HPE Book 9_2076 Edition

water is available to the terrestrial life on Earth. We can study water in terms of surface and ground water. Fresh Water (3%) All Water Marine Water (97%) Ice caps & Easily accessible Fresh Water glaciers (2.4%) surface freshwater (0.1%) Grounded water (0.5%) Easily accessible surface Lakes (52%) fresh water Soil moisture (38%) Water within living organisms (1%) Rivers (1%) Atmospheric water vapour (8%) Fig : 6.2: Distribution of the World’s Water 1. Surface Water The water that is available on the surface of the Earth is called surface water. Rivers, ponds, lakes, streams, wetland are the best examples of surface water. There are more than 6,000 rivers and rivulets altogether in Nepal. Therefore, Nepal is also called as one of the rich countries in fresh water resources. Among them, the rivers like Sapta Koshi, Sapta Gandaki, Karnali, Mahakali, Bagmati, Kankaimai are the big rivers of our country. The main source of surface water is rain water. In the case of the rivers originated from the mountain, their source of water is glaciers of the snow capped high mountain range. 2. Ground Water The water that is available under the surface of the Earth is called ground water. This type of water is recharged through rainfall. As per the report of ICIMOD and ADB, (2006), there is 12 cubic kilometer ground water in Nepal. In the Inner Terai and 151

Bhabar region the water level is observed below 50 feet from the Earth’s surface. Similarly, in the main Terai region water is found about 5 to 10 feet below the Earth’s surface. According to the census report of 2011 AD, 47.78% people use ground water for drinking purpose with the help of tube-well, well, tap, etc. Functions of Water Water is important for the survival of the living beings It is important to generate hydro electricity It is important to run industries It is important for irrigation It is also useful for transportation It is essential for household chores like washing, cleaning, bathing, cooking, etc It is also important for recreational purposes for example boating, rafting, surfing, swimming, etc. Activity Visit various places of your locality. Study the impact of human activities on land and water resources in that area. Discuss about their solutions in the class in the presence of your subject teacher. C. Land (Soil) Land is one of the most important natural resources. Land occupies major component of the lithosphere. The surface area of land is formed by the soil. Soil is the mixture of living and nonliving substances found in the top layer of the Earth’s crust. It is a mixture of weathered rock, materials and organic materials both of which are formed through the physical, chemical and biological processes occurring gradually for a very long period in the Earth’s surface. Soil generally contains the following substances: e Sand e Humus e Water e Air e Soil biota (plant roots, micro organisms) e Minerals of different kinds e Inorganic particles 152

Land according to ecological division: 8. . . 7 Great Himalaya 6 Sub-Himalaya Meters ‘000’ 5 TREE 4 LIMIT Mahabarat Mid Valley 3 Siwalik 2 Bhabar Dun KATHMANDU 1 Tarai HETAUDA TRISHULI 1 2 3 4 5 6 7 k8il ometer9s 10 11 12 13 14 15 .......160 Fig: 6.3: A Cross-Section of the Country Through the Kathmandu Valley a. Mountain Region The mountain region lies to the north from the Mahabharat range. This region has occupied about (35%) of the total area of the country. This region is mostly rocky, barren and snow covered land. The Himalayan chain of mountains starts from about the elevation of 4,000 m above the sea level. The highest peak in the world, Mt. Everest lies in this region along with other peaks. The land is cultivated up to the height of 4,000 meters where clouds hang low over the fields. The soil of this region contains lesser amount of limestone, boulders and humus. The soil of this region is not very fertile and its topography is rough. b. Hilly Region To the north of the Siwalik there lies the larger range of hills known as the Mahabharat, running almost the whole length of Nepal from east to west. This region has occupied almost (42%) land of the total area of the country. The topography of this region is steep. The type of soil of this region Topogrophy of Hill Region is silty and sandy. The composition of silty soil of this region is loam or silty loam. Similarly, the sandy soil contains sand and pebbles so this kind of soil is not suitable for cultivation. Soil erosion is a great problem in this region. c. Terai Region The flat ground between the outermost foothills and the Indian boarder is called the Terai. This region has occupied (23%) of the total land area of the country. This plain 153

Terai is about 25 km broad and runs along the whole length of the country from east to west. In days gone by, most part of the Terai were covered by dense forest, but now these forests can be found only in some parts from east to west. The land of this region is formed by fertile, alluvial and humus mixed sandy soil. The soil of this region contains the elements like potassium, limestone, phosphorus, etc. The land of this region is fertile and very useful for agriculture. D. Forest Resource We can find different types of natural forests in our country due to the topographic diversity. According to the census report of 2001 AD, 64 percent of the total population had been still using firewood as the source of fuel for cooking and other purpose. Forest resource is one of the important natural resources in the environment. Forest is important for various essential things for human beings. For instance, the forest products like forage, medicinal plants, non-wood fibers, gums, waxes, resins, non-timber commodities, timber, wood, wild animals, vegetation etc are very useful. At present, about (29%) of the total area of the country is occupied by the forest and (10.6%) of the land is covered by the bushes and herbs. Similarly, about (12%) area is occupied by the grassland. Due to the variation in topography and climate, there are different types of forest in our country. They are described below: Table 6.2: Distribution of Vegetation of Nepal in terms of Area Vegetation Type Area Occupied in (%) Forest 29 Shrub 10.6 Grassland 12 Total Area of Nepal 1,47,181 km2 Source: Environment Education, TU/IUCN, 2000 AD 1. Tropical Forest This type of forest is found in the southern part of Terai region of Nepal. But tropical forest is found even in Chure region and inner Terai also. In the Southern part of Nepal, this type of forest is distributed up to 1,000 meters altitude. However, in the case of Western part of the country, this type of forest is found up to the altitude of Tropical forest 1,200 meters. It grows in hot and frequently rainfall areas. This type of forest mostly remains evergreen throughout the year. Different species of hard wood trees like 154

Sal, Seemal, Jamun, Dapdape, Budidhayaro, Sahaj, Sisau, Khair, Satisal, etc are found in this forest. The timber of this forest is very valuable for construction work and furniture. This type of forest is playing important role for the protection of wildlife, natural beauty and ecological balance in the country. Status of Tropical Forest in Nepal Tree Species Distribution Importance Sal, Seemal, Altitude Eco-region i. For the protection of wildlife, Jamun, Kusum, i. Eastern natural beauty and ecosystems. Dapdape, part: up i. Main Terai Budidhayaro, ii. Inner Terai ii. Very useful for making furniture Sahaj, Sisau, to 1,000 iii. Chure and construction works meter. Khair, Satisal, ii. Western iii. Very valuable medicinal herbs Pithari, part up are available. Tantari, Valayo, to 1,200 Hallunde, etc. meter. iv. Great role for the conservation of biological resources. 2. Sub-tropical Forest Sub-tropical forest is expanded from the altitude of 1,000 meters to 1,700 meters from the sea level in the Eastern part of Nepal. However, in the Western part of the country this type of forest is expanded from the 1,200 to 2,000 meter altitude. This type of forest is distributed at the lower part of Mahabharat range and upper part of the Churia range. This forest is extended from east to the west of Nepal. The trees like Sal, Semal, Peepal, Bar, Satisal, etc. Laligurans and pine trees are found in abundant number at the upper part of this region and the trees like Uttis, Okhar, Chilaune, etc are available in great number in this forest. This forest also has done great contribution for the conservation of biodiversity and ecological processes. Status of Sub- tropical Forest in Nepal Tree Species Distribution Importance Pankuri, Uttis, Altitude Eco-region i. For the protection of wildlife, Peepal, Kavro i. Eastern i. Mahabharata natural beauty, and ecological Banayan, part: Range balance. Seemal, 1,000 ii. Churiya ii. Very useful for making furniture and construction Sahaj, Satisal, to 1,700 Range works. Sal, Okhar, meters. iii. Very valuable medicinal herbs Chilaune, ii. Western are available. Katus, Lankuri, part: Badahar, Harro, 1,200 iv. Great role for the conservation to 2,000 of biological resources. Barro, Champ, etc. meters. 155

3. Temperate Forest Temperate forest are located in the high hills and lower parts of the mountain region. Temperate forest is also divided into two categories like lower temperate forest and upper temperate forest. In which, the lower temperate forest is extended from 2,000 meter to the altitude of 2,700 meters in the Western part and 1,700 to 2,400 meters Temperate Forest altitude in the Eastern part of the country. The lower temperate forest is also known as warm temperate forest. On the other hand, the upper temperate forest is expanded from 2,700 to 3,100 meters altitude from the sea level in the Western part. However, it is found at the altitude between 2,400 to 2,800 in the Eastern Nepal. This type of forest is also known as cold temperate forest. There is dominance of sub-tropical trees in the lower part of the forest and dominance of alpine trees are observed in the upper part. Hence, this type of forest also can be called as mixed forest. The trees like Dhupi, Bijaya Sal, Peepal, Khair, Sal, Kharsu, Devdar, Laligurans, Rani Salla and the herbs like Timur, Chiraito, Panch Aunle are predominantly present in this forest. The forest products of this forest can be utilized for furniture, medicine, paper and pulp, resin, paint, etc. Status of Temperate Forest in Nepal Tree Species Distribution Importance Dhupi, Altitude Eco-region i. For the protection of wildlife, Bijayasall, natural beauty, and ecological Devdar, i. Eastern i. Mahabharata balance. part: 1,700 Range Kharsu, to 2,800 ii. Very useful for making Laliguras, Rani meters. ii. Churiya furniture and construction Salla, Gobre ii. Western Range works Salla, Okhar, part: 2,000 iii. Very valuable medicinal herbs are available. Chilaune, to 3,100 Katus, Lankuri, meters. iv. Great role for the conservation etc. of biological resources. 4. Alpine Forest Alpine forests are found in the high mountain region. Alpine forests are also divided into two clusters such as lower alpine forest and upper alpine forest. Lower alpine forest is found at the altitude of 3,100 to 4,200 meters in the west and 2,800 to 3,000 meters in the Eastern part and upper alpine shrub land is extended from the altitude of 4,000 to 4,500 meters. 156

The trees like Gobre Salla, Dhupi, Bhojpatra, Devdar, Juniper, Thigure Salla, Laligurans are found in the lower alpine forest. Similarly, smaller species of Laligurans, Lichens, moses, bushes and grass are available in the alpine zone of the forest. Forest resources of Nepal have greater importance. They are the sources of wood and non wood forest products. Besides this, it is Alpine forest also the common habitat of many valuable species of mammals, birds, reptiles, amphibians and so on. Similarly, the diversified vegetation supplies different varieties of pulp wood, fuel wood, medicinal plants and beautiful flowering aromatic plants. At the same time, it also plays an important role in balancing ecosystems. Status of Alpine Forest in Nepal Tree Species Distribution Importance Gobre Salla, Dhup Sallai, Altitude Eco-region i. Important habitat of Bhojpatra, many valuable species of Devdar, i. Lower alpine mammals, birds, reptiles, Thigure Salla, forest: 3,100 to insects and ecological Laligurans 4,200 m in the balance. Rani Salla, West & 2,800 to Chilaune, etc. 3,000 meters in Mountain ii. Sources of wood and non the East. Region wood forest products. ii. Upper alpine iii. Source of valuable medicinal shrub land: 4000 plants and beautiful to 45,000 m. flowering aromatic plants. iv. Great role in balancing ecosystems. E. Wildlife Although Nepal represents (0.1%) of the world’s land surface area it comprises over (2%) of the world’s flowering plants and (2.2%) of the world’s recorded plants. Similarly, Nepal’s known species of birds comprise approximately (9.4%) of the world’s total recorded bird species. Nepal is rich in biological diversity due to the variation in topography, climate and altitude. It has created a favorable environment for the conservation of wildlife in our country. According to the data of biodiversity project profile prepared in 1995 AD, about 5,160 species of flowering plants, 181 species of mammals, 856 species birds, 640 species of butterflies, 5,000 species of insects 100 species of reptiles 43 species of amphibians, over 700 species of medicinal plants and 185 species of fishes are found in our country. 157

In the same way, the reptiles like Gharial Crocodile, Golden Monitor Lizard and Asiatic Rock Python are found in Nepal. Along with this, there are dozens of species of poisonous and nonpoisonous snakes which are also found in our country. The wildlife has played great roles in social, economic and environmental aspects. F. Minerals Minerals are the substances such as Tin, Salt, Sulphur, Copper, Coal etc. Minerals are also one of the important natural resources found in the Earth’s crust that are formed naturally in rocks and Earth. About 99% of the Earth’s crust consists of compounds of eight elements like Oxygen, Silicon, Aluminum, Iron, Magnesium, Calcium, Sodium and Potassium. In Nepal, Geological Survey and Exploration of minerals in scientific way was started from 2024 BS. Since then, various mineral industries have been established in our country. Some of the examples are Cement industries, Limestone industries, Marble industries, Slate industries, etc. Proper utilization and exploration of minerals is essential to promote the economic development of the nation. Some minerals discovered from the survey and exploration are given below: 1. Iron Ore Iron is an element which usually takes the form of a hard, dark, grey metal. Iron ore is one of the principal natural resources of Nepal. According to the survey report, the deposits of iron are found in Phulchoki (Kathmandu), Ramechhap, Chitwan, Makawanpur, Nuwakot, Pyuthan. It is estimated that 3.6 million tonnes of iron ore are deposited in Phulchoki. It is essential for the construction of buildings, bridges, machineries, equipment, weapons, etc. 2. Copper Copper is another important mineral resource of Nepal. It is found in various places of the country like Makawanpur, Tanahu, Gorkha, Nuwakot, Ilam, Sindhupalchok, Taplejung, Baglung and Baitadi. Copper is widely used to make utensils, electrical wires and so on. 3. Lead Lead is a soft, grey heavy metal. It is also an important mineral resource of our country. It is found in Makawanpur, Rasuwa, Baglung, Nuwakot and Bhajhang. It is important for the manufacturing of colour, pencil and batteries. 4. Mica Mica is a hard mineral which is found as a small flat crystal in rocks. It has a great resistance to heat and electricity. It is also an important mineral resource of Nepal. It is found in Bajhang, Chainpur, Doti, Bhojpur, Lamjung, Nuwakot, Dhankuta and Sindhuli. Mica is widely used to make electrical materials. 158

5. Limestone Limestone is a whitish coloured rock. It is a principal mineral resource of Nepal. It is found in various places of Nepal like Chobhar (Kathmandu), Dhading, Makawanpur, Dhankuta, Hetauda, Udayapur and Pokhara. Limestone is used for making cement, chalk, etc. Table 6.3: Limestone Deposits of Nepal with Production Capacity Place Deposits (in crore tonnes) Cement Production/day 800t/day Udaypur (Sindhuli) 7.0 400t/ day Not Mined Choabhar (Kathmandu) 1.53 775t/day Not Mined Nigale (Dhankuta) 1.15 Not Mined Okhare (Hetauda) 1.9 Bhaise (Makwanpur) 0.8 Total (estimated deposits) 12.38 Source: Environment Education, TU/IUCN Nepal, 2000 AD 6. Talc Stone (Khari Dhunga) Talc stone is also an important mineral deposits of Nepal. It is found in Baglung, Sindhupalchok, Dolakha and Udayapur. It is widely used for making talc powder and other cosmetics. 7. Slate Slate is a dark, grey rock that can be easily split into thin layers. It is found in Tanahu, Kaski, Bajhang, Gulmi and Dhading. It is also explored in western, mid-western and eastern hill region. Slate is used to decorate house and cover roof. 8. Coal Coal is a hard black substance that is extracted from the ground and burned as fuel. Coal deposits are found in Dang, Salyan, Kailali, Chitwan, Mustang, Baglung and Kanchanpur. It is an important sources of fuel energy. But the quality of the coal found in Nepal is proved to be poor. 9. Nickel Nickel is a silver coloured metal. It is found in various places of Nepal like Ramechhap, Sindhupalchok and Dhankuta. It is used for making high quality steel and coating metals. 10. Gold Thin flakes of gold are found in the sand of several rivers of Nepal. Kaligandaki, Marsyandi, Budhigandaki, Sunkoshi, etc are supposed to have gold deposits. It is 159

widely used for making jewellery, sculpture, topping the metal’s outer surface and as an international currency. 11. Petroleum Products and Natural Gas Petroleum is oil which is found under the surface of the Earth or under the sea bed. The places like Mustang, Dailekh, Dang, Salyan, Pyuthan, Surkhet, Jhapa, Morang are the possible area of petroleum and natural gas deposits. Similarly, sufficient quantity of Methane gas has been found in Kathmandu valley. Table 6.4: Minerals of Nepal with Location and their Uses and Importance SN Name of Location Importance the mineral 1. Iron Ore Phulchoki (Kathmandu), Construction of buildings, Ramechhap, Chitwan, bridges, machineries, Makawanpur, Nuwakot, equipment, weapons Pyuthan 2. Copper Makawanpur, Tanahu, Gorkha, Copper is widely used to make Nuwakot, Ilam, Sindhupalchok, utensils, electrical wires and so Taplejung, Baglung on 3. Lead Makawanpur, Rasuwa, Baglung, It is important for the Nuwakot and Bhajhang manufacturing of colour, pencil and batteries. 4. Mica Baglung and Udayapur It is widely used for making talc powder and other cosmetics 5. Limestone Chobhar (Kathmandu), Limestone is used for making Dhading, Pokhara, cement, chalk, etc. Makawanpur, Dhankuta, Hetauda, Udayapur 6. Talc power Baglung and Udayapur It is widely used for making talc powder and other cosmetics. 7. Slate Tanahu, Kaski, Bajhang, It is used to decorate house Dhading and cover roof. 8. Coal Dang, Salyan, Kailali, Chitwan, It is an important sources of Mustang, Baglung and fuel energy. Kanchanpur 9. Nickel Ramechhap, Sindhupalchok It is used for making high quality and Dhankuta steel and coating metals. 160

10. Gold Kaligandaki, Marsyandi, Making jewellery, topping the Budhigandaki, Sunkoshi metal’s outer surface and as an international currency. 11. Petroleum Mustang, Dailekh, Dang, It can be useful for fuel. products Salyan, Pyuthan, Surkhet, Jhapa, Morang 6.3 Conservation of Natural Resources Human life is possible through the natural resources. Humans utilize natural resources to fulfil their needs. For this purpose, man should make best use of natural resource. This helps to maintain natural balance between consumption and preservation of natural resources. If we continue this principle while utilizing the resources, the ecological process of nature will automatically keep ecosystem in balance. In fact, utilization of natural resources without disturbing their regeneration and restoration process is called Growing Fruit Trees in Vases conservation of natural resources. Conservation of natural resources comprises the efforts to reduce unnecessary resource waste, prevent over use of renewable natural resources and preservation of nonrenewable natural resources. 6.3.1 Conservation Principle of Natural Resources Conservation of natural resources means using those natural resources without hampering their restoration and regeneration process. Conservation of natural resources helps to keep environment in balance. If human beings develop positive interaction with the environment; it helps in conservation of the natural resources. Various types of approaches exists for the conservation of natural resources. Some of the common conservation approaches are popularly known as Absolute Conservation and Relative Conservation approaches. They are explained below: A. Absolute Conservation Absolute conservation is that conservation principle in which natural resources should be kept in existing state without any disturbance. In other words, the conservation approach of maintaining natural resources in the same quantity and quality is called absolute conservation. In this approach, natural resources are preserved without using them. This approach is more suitable for the conservation of rare and endangered species of biological resources. This conservation principle has been widely applied in the Ex-Situs and In-Situs like Zoo, National Park, Wildlife 161

Reserves etc. Here, In-Situ is the conservation areas in which biological resources are protected inside their natural habitats whereas Ex-Situ is the conservation areas in which biological resources are preserved outside their natural habitats. National Parks, Wildlife Reserves and Conservation Areas denotes the In-Situ while Ex-Situ comprises the conservation areas like zoo, botanical gardens, nurseries and sanctuaries etc. It is difficult to follow this principle to conserve natural resources in every time and situation because we cannot survive without utilizing natural resources. B. Relative Conservation Relative conservation is that conservation principle in which conservation and consumption of the natural resources should be conducted together in an integrated way. In this approach, people should not disturb the regeneration and restoration process of the resources while consuming them. The practices like less use, reuse and recycle of nonrenewable natural resources play positive role in relative conservation. Similarly, the consumption of renewable resources like animals, birds, plants and forest resources according to their reproduction and regeneration capacity help for their conservation. This approach helps to maintain co-ordination between the natural resources and living being including human. This conservation principle can be applied for those resources which are available in sufficient quantity and population at present. This principle is successfully practiced in the Community Forests programme in Nepal. It is the most appropriate conservation model except the resources which are not in endangered state. The differences between Absolute and Relative conservation principle of natural resources is demonstrated in the following table: Difference between Absolute and Relative Conservation Absolute Conservation Relative Conservation • Absolute conservation refers to the • Relative conservation refers to the conservation of natural resources conservation and utilization of the without using them at all. natural resources once at a time. • This conservation principle is • This conservation principle is absolutely applicable in the In-Situs absolutely applicable in community and Ex-Situs. forest, poultry, bee keeping, etc. • This principle is more appropriate • This principle is appropriate for the for the preservation of endangered conservation of renewable natural species of biological resources. resources. • It is more theoretical conservation • It is more applicable conservation approach. approach. 162

• The management of national parks, • The management of community wildlife reserves, zoo and conservation forest, poultry farming, fish farming, areas denote the examples of absolute bee keeping denote the examples of conservation principle. relative conservation principle. 6.3.2 Conservational Use of Natural Resources Rationale use of natural resources by sustaining their quality and quantity is called conservational use of natural resources. The objective of conservational use is to conserve and keep the natural resources for future generation. Conservation use has basically three main objectives such as: to maintain essential ecological processes and life support system to preserve biodiversity to ensure that any utilization of species and ecosystem is sustainable Conservation of natural resources, therefore makes important contributions to social and economic development without degrading the balance of ecosystem and nature. The conservational use encompasses the following principles: Optimum utilization of perpetual natural resources. Maximizing the regeneration capacity of renewable natural resources. Nominal and rational use of nonrenewable resources. Reuse and recycle of the products time and again made from the nonrenewable natural resources. Conservation of sources of energy by utilizing the alternative sources of energy. In fact, recycle and reuse practices save our expenses and valuable resources. Hence, it helps us to prevent from energy crisis and environmental pollution. Therefore, this kind of resource recovery process needs to be encouraged for sustainable management of resources. To translate the knowledge of conservational use of natural resources, people need to transform their knowledge into day to day life. For instance, they need to follow the reduction and recycling principle while using materials. They should not involve in deforestation and environmental pollution causing activities. At the same time, they need to make clear concept about the conservational use of natural resources too. Activity Conduct an interaction programme on need of conservational use of natural resources for sustainable development in your school. 163

6.4 Care for the Earth 6.4.1 Introduction to Care for the Earth The Earth is only one living planet in the universe. It is the common habitat of the living beings. The Earth is so kind to man including other living beings. But rapidly increasing human population have expanded their needs. With scientific progress and technological development man started utilizing natural resources at a much larger scale. It will create a dreadful situation when the nonrenewable resources may come to an end after few decades. As a result, we would be using all those resources which are in fact the property of future generation. This condition will make survival of the living beings very difficult. In effect of global realization about the urgent need to conserve the natural resources, the world conservation strategy (WCS) was prepared in 1980 AD by the joint effort of UNEP, WWF and IUCN. It has made contribution to prepare foundation for the integration of natural resource conservation and development activities. This strategy has focused on sustainable life of the living The Common Habitat of all living beings beings. IUCN, WWF and UNEP jointly introduced the strategy of caring for the Earth in 1991 AD under the backdrop of the WCS. Generally speaking, caring for the Earth refers to the sustainable use of natural resources, minimize the environmental degradation and pollution and maintain the Earth as the favourable shelter for all living beings for years. The national and international agencies and Non-governmental Organizations (NGOs) have agreed to implement the strategy of caring for the Earth. It was launched on 4th Kartik 2048 BS in more than 55 cities including, London, Tokyo, New York, Kathmandu and so on. Major Principles of Care for the Earth The World Conservation Strategy (WCS) has adopted the following guideline principles for the caring of the Earth: e Promotion of renewable resources and preservation of nonrenewable resources e Conservation of biodiversity e Maximizing the utilization of alternative sources of energy and technology e Reduction of gap between rich and poor e Integration between conservation of resources and development programmes e Utilization of natural resources for sustainable living 164

6.4.2 Earth as a Living Planet Earth has a distinct feature in comparison to other planets in the solar system. The unique characteristics like situation, temperature, revolution, climate and distance have made the Earth as a living planet. The Earth is about 15 crore kilometers far away from the Sun. Hence, it has become a favorable place for living beings. Earth is the only one habitat for the living beings among the planets. Living beings can survive on the Earth due to the presence of air, water, sunlight, food chain and favorable habitats. There is a vast varieties of living beings in different natural settings like land, rivers, oceans, forests, grasslands, ponds etc. These regions such as land, rivers, oceans, forest, etc are inseparable parts of the Earth and they are interrelated to each other. It is also called Biosphere. It also can be termed as biological world or biotic world. It is possible to be formed by the Lithosphere, Hydrosphere and Atmosphere. This favorable condition has made this Earth to be a common habitat of all the living beings in the world. Some of the features of the Earth which have made this planet as a living planet are as follows: Continental Crust A. Land Structure Oceanic Crust Lithosphere The land part of the Earth is called Crust 2900 km Lithosphere. It contains three layers 5100 km Upper Mantle such as the outermost layer called Crust, the middle Mantle and the Mantle inner part Core. Lithosphere has occupied about (29%) of the total Lower Mantle Outer Core Core Inner Core area of the Earth. The terrestrial 6378 km living beings live on the Crust. It is Structure of the Lithosphere the solid outermost zone or surface of the Earth. It is 40 to 50 km thick on land and 5 km thick on the sea bed. The crust surface contains soil, igneous and sedimentary rocks. Its structure varies with respect to topography and altitude. There is variation of ecosystems on the Earth due to the variation of land topography and vegetation. The plants and animals are found different due to the variation in ecosystem. So, various types and species of organisms can exist in this planet. B. Air Atmosphere has surrounded the Earth. It is composed of Nitrogen, Oxygen, Carbon dioxide, Hydrogen, Water Vapour, dust particles and inert gases. Survival of the living beings has become possible due to the presence of Oxygen in the atmosphere. There are different layers in the atmosphere. In which, there is a very important life 165

supporting layer called ozone layer that THERMOSPHERE protects the living beings and vegetation from the harmful ultraviolet radiation. MESOSPHERE Due to the presence of ozone layer in the STRATOSPHERE Stratosphere the required sunlight reaches TROPOSPHERE the Earth’s surface that helps the vegetation and animals to conduct their life processes. C. Season Change The Earth revolves around the Sun in its Structure of the Atmosphere own orbit. Due to this rotation there is systemic change of the seasons. The natural process such as change in season, day and night, variation in temperature, rainfall, wind, storm, precipitation, climate change, etc are continuously going on in the Earth. As a result, there are different kinds of climate in different seasons. Living beings adopt themselves to survive in different weather and climate occurring on the Earth. D. Water Water is a compound made up of one part Oxygen and two parts Hydrogen. It is the very essence for life on the Earth. Of the total surface of the Earth, about (71%) is covered by water bodies such as oceans and seas. Less than (3%) of the world’s water is fresh water. The Earth is the only single planet containing water which has made it as a living planet. Rivers, streams, lakes, ponds, seas and oceans are the sources of water on the Earth. E. Heat and Light The main sources of light and heat is the sunlight. Sunlight is the main source of energy of the living beings. Light energy is essential for different life process of the living beings. Plants need it for chlorophyll production, transpiration and growth. Similarly, animals need light energy for growth and development, metabolism, reproduction and various activities. At the same time, hydrological cycle is possible only with the help of heat from the sunlight. So, the presence of adequate heat and light from the sun has made animals and plants life cycle possible in this planet. F. Food Chain Food is the most fundamental need of living beings including humans. Life is not possible in its absence. Plants prepare their food themselves through photosynthesis process. The herbivorous animals get their food from green plants. Similarly, carnivorous and omnivorous animals get food from the predators like plants, animals and insects. In this way, plants and animals are linked together by their nutrition requirement which develops a nutrient interlink called food chain. 166

When the animals and plants die out Sun they are decomposed by the microbes and consequently, decomposed Plants Herbivores Carnivores Omnivores organic and inorganic materials are again returned to the producers. This unique feature of the Earth has made it a living planet. G. Recycling Decomposers All the animals and plants die out one Food Chain day. The decomposers decompose them and they are mixed up into the soil. Then those organic and inorganic raw materials become nutrients for the green plants and vegetation. Again they supply food to the consumers. In this way, the nutrient recycle process continues. This process continues in the ecosystem. This very nature of recycling process of nutrients between producers, consumers and decomposers have made our Earth as a living planet. 6.4.3 Need for Caring for the Earth It is obvious that the Earth is the habitat of all living beings. We get all kinds of life supporting resources from the Earth. People conduct various activities like construction of road, bridge, buildings, drainage, establishment of industries that may affect the ecological balance of the Earth. The effects which are seen at present may be serious challenge in the future. So, we should conduct our activities by considering the fact that we are not disturbing the balance of natural environment. Hence, proper care of the Earth is essential. Some major reasons needed for caring the Earth are mentioned below: A. Conservation of Natural Resources Air, water, forest, land, vegetation, minerals are the integral parts of the Earth. People use natural resources to fulfill their basic requirements. But unplanned development activities and over exploitation of resources go against the nature. This may result into various problems like Flood, Landslide, Desertification, Deforestation, Acid Rain, Global warming, etc. So, natural resources should be utilized without decreasing their deposits. In this way, the sustainable use of natural resources helps to take care of the Earth. Conservation of Natural Resources 167

B. Conservation of Living Beings Plant Protection The Earth is the home of all living beings. There are millions of living beings living in different natural surroundings choosing their own habitats. Some are aquatic and some are terrestrial by their habitats but they are interrelated and interdependent. If one of them is destroyed the other will be affected. So, conservation of plants and animals is essential for the conservation of life on the Earth. For this, we should be responsible and conduct activities accordingly, that support the conservation of natural resources, conservation of flora and fauna and conservation of environment. It will help in fulfilling the guiding principles for the care of the Earth. 6.4.4 Measures of Caring for the Earth The care and conservation of the Earth has become a felt need. In this juncture, the care for the Earth will be easy if people develop positive attitude. Such attitude also helps for the existence of humans themselves. Its main objective is to undertake programs of caring for Earth at local, national and global level in different sectors. Some measures need to be adopted for caring for the Earth are mentioned below: A. Knowledge of the Structure of the Earth In order to support the programs on caring for the Earth, it is necessary to know about the structure and functional process of the Earth. In this situation, the knowledge of Biosphere, Atmosphere, Hydrosphere, Lithosphere, seasonal change, land topography will support the Earth care programs. Hence, it is essential to have knowledge on Earth’s situation and the importance of its revolution process. Such knowledge inspires us to participate in Earth care programs. B. Respect to the Nature People should learn to live and abide by the rules of nature. We should not go against nature for the greed of money. Our social and cultural traditions help to respect the nature. Everyone has to respect the environmental aspects of their locality. Such activities may support the programs for caring for the Earth. C. Nature friendly Development People conduct various development activities for their better and productive life. Those development activities should be conducted within the carrying capacity of the Earth. For this, we should put environment in the centre while carrying out any kind of development activities. At the same time, we should follow the principle 168

of sustainable development so that we can carry on development activities and resources conservation programs side by side. So, that development programs will be in harmony with environment in favor of caring the Earth. D. Proper Utilization of Natural Resources People are using natural resources to fulfill their various needs. So, they have to consider resource sustainability and the impact on future generation while exploiting the resources. These rational activities help to improve living standard of the people. But over exploitation and unsustainable use of natural resources worsens the condition. Hence, we should develop positive attitude and behaviour for sustainable use of natural resources which eventually supports caring of the Earth. E. Involvement in Conservation Activities It is our prime responsibility to take care of the Earth since it is the common habitat of all the living beings. Caring of the Earth depends on the conservation of ecosystems. For this, various programs can be conducted for the protection of ecosystems and regulation of ecological balance. So, we should participate actively in those conservation programs. We can make plans and implement conservation programs for the protection of ecosystem. Conserving ecosystem means conserving our common habitat. 6.4.5 Major Programmes for the Caring of the Earth It is the prime responsibility of Boon of the Earth all people to care for the Earth. A single nation’s efforts to conserve and care for the Earth is almost impossible. So, all the countries should put equal efforts to conserve ecological balance on the Earth. Different countries and territories can conduct different conservation programs according to the priority of requirement. Some of the programs for caring for the Earth are mentioned below: A. World Conservation Strategy Earth is the common habitat of all living beings. They will get extinct if the Earth is not provided proper care. So, the policies and programs for the protection of the Earth is the need of today. But unless conservation policies are translated into 169

realistic operational programs, the expected WORLD results cannot be realized. The programs can CONSERVATION only be effective when there are adequate human resource, technology and financial STRATEGY resources to support and implement them. In this situation, the World Conservation Strategy Living Resource Conservation for (WCS, 1980) has managed various conservation Sustainable Development policies like: conservation of habitats, conservation of biodiversity, conservation Three Man Objectives: of soil, conservation of forest resources, 1. Maintain essential ecological processes and life support systems conservation of wildlife, conservation of wet- 2. Preserve genetic diversity essential to improving cultivated land ecosystem etc. At the same time, IUCN, WWF and UNEP have jointly introduced plants and domestic animals strategy for caring for the Earth for the world in 3. Ensure that utilization of wild species and ecosystems is 1991 AD. These conservation strategies in fact help to protect the Earth’s resources. sustainable B. National Conservation Strategy Objectives of WCS, 1980 AD There must be national policies to conserve the various aspects of the Earth like natural, biological, physical, social and cultural aspects. Being the party country of the World Conservation Strategy, most of the countries have developed their own national conservation policies and implementing at local and national level. Our country also had executed National Conservation Strategy in 1988 AD. The National Conservation Strategy has given emphasis on sustainable development, conservation of biodiversity and resources, integrated resource management, environmental education, environmental impact assessment (EIA) etc. In the same way, different programs like community forest programme, soil conservation, watershed conservation etc are conducted at local level. But environmental management at local level can only be effective when the local governments are capable of managing and monitoring environmental quality in their jurisdiction. Anyway, these programs certainly help in caring for the Earth. C. Environmental Planning All the countries carry out development activities for their social, economic and cultural development. There must be integrated programs for sustainable development and proper management of natural resources side by side. Environment related programs with long term vision and goal is called environmental planning. Environmental planning eventually support for sustainable development and resource conservation. In this matter, Nepal also has given priority for environmental issues by including a separate chapter for environment and resources conservation from its eighty five year plan (1992-1997 AD). 170

D. Formulation of Policies and their Implementation Various policies and laws have to be formulated for the protection of natural resources. Those polices and laws need to be translated into effective implementation in programme level. Such efforts have been initiated by different countries. Our country also has been formulating some dozens of conservation laws and environment conservation polices in different time periods. For instance, the National Conservation Strategy was implemented in 1988 AD in order to preserve biological diversity, to ensure the sustainable use of land and renewable resources and to maintain ecological and life support systems. Similarly, the Nepal Environment Policy and Action Plan was endorsed by the government in 1993 AD with the purpose of conservation management and expansion of rare plants and wildlife, including wetlands. Finally, we can conclude that good policies and its effective implementation can support the Earth care strategy. E. Institutional Reform There are various organizations and agencies, involved in utilization of natural resources of the Earth. There are large number of industries which directly depend upon natural resources for raw materials. In this condition, the knowledge, skill and technologies should be developed and extended on them to utilize resources rationally. At the same time, they should be encouraged to conduct programs on caring for the Earth. In this condition, the government of Nepal also has reformulated its policies and programs as well as provisions in existing laws according to the present needs for resource conservation. F. Awareness Raising Programme Different awareness programs should be conducted at local, national and international level for caring of the Earth. Such programs motivate people for their involvement in caring of the Earth. Local people should be the target population in such programs because their participation is important for the protection of resources and ecosystem. So, awareness programs should ensure the active participation of local communities for the Environment Awareness Campaign conservation activities. Different countries including our country have carried out such programs according to their needs. 171

Activity Prepare an one act play about the effect of over exploitation of natural resources on the social, economic and environmental aspects and perform it in the school program. 6.4.6 Man and the Earth Earth is the common habitat of all the living species including human beings. The Earth provides us with all our essential needs such as; air, water, food, shelter and so on. People conduct various activities by utilizing the resources of the Earth to fulfill their needs and aspirations. Various types of constructional and developmental works are done on the Earth. If we conduct these activities without proper planning and Environmental Impact Assessment (EIA), it adversely affects the natural environment. Our irrational activities over the natural resources causes various problems like Flood, Landslide, Acid Rain, Deforestation, climate change, loss of biodiversity, Ozone depletion etc. Therefore, there must be sustainable use of natural resources while using them to fulfill our needs. Various programs are necessary to protect the resources of our common habitat for present and future generation. All the living beings of the Earth are interdependent to one another. It is essential for the people to develop positive attitude and behaviour to the nature. We should pay respect and honour to the nature. Our activities should not hamper life system of other living beings of the common habitat. We should maintain natural balance of ecosystem while getting benefits from the available resources. So, we should keep harmony in human needs and resource conservation for caring of the Earth. We need to pay our attention in the following areas to care for the Earth: • Our day to day work or activity should help in the reduction of the emission of green house gases. • There should be rational use of natural resources. • We should not forget that we can survive if the Earth exists. Measures to Improve the Interaction between Man and the Earth e There should be proper and rational utilization of natural resources. e Development activities need to be carried out according to the plan. e There should be optimum utilization of modern technology but it should not hamper the environment. e Our activities should not go beyond the carrying capacity of the Earth. e We need to learn to adjust with the rule of the nature (adaptation skill) e We need to develop environment friendly attitude and behaviour. e Focus should be given on forestry and agriculture education. 172

Activity Organize a speech competition on the topic “Relation between man and natural resource” in your school with the help of your teacher. 6.4.7 Local Level Efforts for Caring for the Earth Environment conservation programs can be conducted at different levels such as local, national and international level. But focal point should be the local level conservation programs. The way of conserving the resources varies at local level from place to place. Some possible programs to carry out at local level for caring for the Earth are as follows: Tree plantation in open areas and barren land helps to increase greenery While collecting the forest products like timber, firewood, dried twigs, grass and leaves from forest we should not destroy small plants Community should safeguard the religious places, public places, open ground, rivers, streams, ponds, wetlands, etc Community should take initiation for the sanitation, drainage and solid waste management programmes We should not do cultivation in the very steepy land and marginal areas We should do plantation of trees at the edge of farmland and at the bank of the rivers, lakes and ponds Participation of community should be increased for the preservation of cultural heritages like temples, monasteries, mosques, etc We should replace chemical fertilizers and pesticides with compost manure and bio- pesticides We should educate the people about water harvesting from the rain water in the dry areas We should encourage the people for management of population and stop unmanaged settlement Encourage the community for the use of alternative sources to preserve nonrenewable resources We should disseminate information to the people about the conservation and promotion of the environment Activity List down the impact of various human activities on the ecosystem of your locality in a chart paper. Put it on the black / white board of your classroom and discuss about the solution in the presence of your subject teacher. 173

Summary M Caring for the Earth refers to the sustainable use of natural resources, minimizing the environmental degradation and maintains the Earth as the favourable shelter for all living beings. M Carrying capacity means the capacity to make possible the existence of the maximum population of living beings (biological species) with the available food materials, water, air, habitat, and other necessary things available in the environment. M The World Conservation Strategy (WCS, 1980 AD) has formulated various conservation policies like Conservation of wildlife habitats, conservation of biodiversity, conservation of forest resources, conservation of wetland ecosystem, etc. M The National Conservation Strategy (NCS, 1988 AD) of Nepal has given strong emphasis on sustainable development, conservation of biodiversity, integrated development, environment education, and environment impact assessment (EIA). M The resources like air, water, soil, minerals, forest, temperature etc available in nature for our survival, growth, development, and life cycle are called natural resources. M The natural resources, which never get exhausted despite their continuous use are called perpetual natural resources. (eg. solar energy, wind energy, tides, flowing water, etc). M The natural resources, which can be regenerated or restored in certain duration of time, are called renewable natural resources. (eg. fertile soil, fresh air, clean water, animals and plants, etc). M The natural resources which cannot be regenerated or restored once they are exhausted or finished are called nonrenewable natural resources. (eg. fossil fuel, metallic minerals, non-metallic minerals, etc). M Of the total volume of world water, (97%) is in the Ocean and the fresh water occupies the remaining (3%). Out of the (3%), also (2.4%) is frozen in the South and North Poles and the high mountain peaks and the remaining (0.5%) and (0.1%) water is available as the surface and ground. M Nepal is rich in biodiversity due to the variation in altitude, topography, ecosystem and climate. M Absolute conservation refers to the conservation of natural resources without using at all. M Relative conservation refers to the conservation and utilization of the natural resources at the same time. M The sum total of carrying capacity of various geographical regions is considered as carrying capacity of the Earth. 174

Exercise A. Very short answer questions. 1. What do you mean by natural resources? 2. Define absolute conservation principle. 3. Write any two importance of Limestone. 4. Mention any two conservation methods of natural resources. 5. What do you mean by caring for the Earth? 6. Write two points which show the necessity of caring for the Earth. 7. What is the carrying capacity of the Earth? 8. Mention any two conservation activities of National Conservation Policy with reference to Nepal. 9. What is absolute conservation principle? 10. Mention any tow importance of Mica. B. Short answer questions. 1. Classify the natural resources and explain them in brief. 2. Explain briefly about air and mention its functions. 3. Explain the types of water sources and its functions. 4. Why is conservation and proper utilization of natural resources essential for the sustainable development of the nation? Explain. 5. Explain the land resource of Nepal according to ecological division. 6. Mention any four importance of natural resources. 7. Explain the relationship between man and the Earth. 8. Explain any four major programmes for caring for the Earth. 9. Natural resources should be consumed within the limit of carrying capacity of the Earth. Why? Give reasons. 10. Mention any four approaches of the World Conservation Strategy for the care of the Earth. C. Write short notes on: 1. Minerals of Nepal 2. Wildlife of Nepal 3. Earth as a living planet 4. Caring for the Earth 175

5. Environmental planning 6. Carrying capacity of the Earth D. Write differences: 1. Absolute and Relative conservation 2. Perpetual and Renewable natural resources 3. Worldwide conservation and national conservation policy E. Long answer questions. 1. What is mean by care for the Earth? Explain the major programmes for the caring of the Earth. 2. What is forest resource? Explain the types of forest of Nepal. Project Work Write a report to the your VDC/Municipality office about the local environment conservation programs conducted by any one NGO that you have observed in your locality. a. Name of the NGO b. Objectives of that NGO c. Location of the Conservation Program d. Socio-economic and environmental impact of that conservation program: Impact of the Program Social Aspect Economic Aspect Health Aspect Environmental Aspect 1. ......................... 1. ......................... 1. ......................... 1. ......................... 2. ......................... 2. ......................... 2. ......................... 2. ......................... 3. ......................... 3. ......................... 3. ......................... 3. ......................... 4. ......................... 4. ......................... 4. ......................... 4. ......................... 5. ......................... 5. ......................... 5. ......................... 5. ......................... 176

Unit ENVIRONMENTAL HEALTH 7 Learning Objective After completing this unit, students will be able to: • Clarify the concept of environmental health and pollution. • Describe the causes, effects and controlling measures of environmental pollution. • Analyse the various management methods of solid waste. • Explain the different compost preparation methods. • Compare various types of latrines. 7.1 Concept of Environmental Health The term ‘Environment’ has been derived from the French words ‘Environ’ and ‘Ment’. Its literal meaning is wind circuit. Hence, its common meaning is those external factors which exist in our surrounding and determine our survival, growth, development and day to day activities. Hence, the factors like land, water, forest, animals, plants and so on exist in our surrounding can be considered as the components of environment. Environment is precious and essential to us. We can not imagine human life without environment. In fact, condition of environment determines the quality of living standard of people. It means, people can have healthy and productive life in good environment. In this context, the process of promoting the condition of human health by improving the quality of the components of environment can be considered as environmental health. Under the initiation of the UN, since 1972 AD, 5th June is being celebrated as the World Environment Day. Nepal also celebrates this auspicious day as the environment day every year. Environment Protection Act, 2053 BS and Environment Protection Regulation, 2054 BS has made a great contribution for the conservation of environment and pollution control programs. Environmental health is an important aspect of human life. Various activities related to physical, biological and socio-cultural aspects affect the condition of 177

environmental health. We know that the health of an individual is determined up to some level by his/her internal and external environment. In this regard, we study various components of environment and their impact on human health in Environmental Health. Environmental health is related with human health and quality of life. The concept of environmental health is developed to address the essential factors of quality of life such as physical, biological, social and cultural factors of environment. The concern of environmental health is the promotion of human health by maintaining environmental components. It includes the activities like conservation, management and proper utilization of environmental resources to uplift human health. According to WHO; “Environmental Health is the field of science that studies how the environment influences human health and disease. ‘Environment,’ in this context, means things in the natural environment like air, water and soil, and also all the physical, chemical, biological and social features of our surroundings”. The ultimate goal of environmental health is to control possible negative impact and maintain healthy environment for qualitative and productive life. Environmental health affects everyone. Human beings are dependent upon their environment. So, for the promotion of human health, the environment should be clean and free from hazards. In this regard, environmental sanitation is the most essential component for healthy human life. Hence, environmental sanitation and human health are inseparable aspects. Some major areas of environmental health are: e Proper disposal of waste materials, sewage, human excreta and refuse, e Supply of clean and safe drinking water, e Proper housing, e Safe distribution of milk and other food materials, e Personal hygiene, e Control of environmental pollution, e Clean environment. 7.2 Environmental Pollution and Management of Pollution People conduct different development works and activities in the environment. They use different types of resources to accomplish those works. The haphazard development activities without giving concern about environmental aspect ultimately degrades the balance of environment. Such activities result into various types of environmental pollution. Unmanaged industrialization, unplanned urbanization, unsustainable development activities, experiment of radio-active weapons are some examples which directly and indirectly deteriorates the balance of environment. These activities may cause water pollution, Acid Rain, climate change and many more life threatening fatal diseases spread to the human beings. 178

Since the rational beings, it is our responsibility to control and make proper management of pollution. Since, the whole Earth is the common habitat, we should put all possible effort for the control and management of pollution. 7.2.1 Introduction to Environmental Pollution Population growth has become a major factor affecting the environment of the Earth. Due to rapid population growth, humans have started exploitation of natural resources ruthlessly. It has reached a stage wherein Earth’s in-built ecosystem is adversely affected. We must reduce the effects of pollution on environment from our level best. Actually, pollution is a man-made problem basically of effluent or industrialized countries. Thus, pollution has become a necessary evil of all development. In this situation, pollution control should be the great concern for all (i.e. the local community, nation and the world). Environmental pollution can be defined as ; pollution is and undesirable change in the physical, chemical or biological characteristics of air, water and soil that may harmfully affect the life or create a potential health hazard of any living organisms. The pollution causing substances are called pollutants. A pollutant may include any of the chemical, geochemical, physical or biotic components or its products. A. Importance of Environmental Health i. Helps to identify the relation between health and environment. ii. Motivates for environmental sanitation and management of solid waste. iii. Makes responsible towards the pollution controlling measures. iv. Helps to be prevented from the prevalence of pollution borne disease. v. Helps to maintain individuals physical and mental health in proper order. vi. Helps to conserve and balance the environment. B. Measures to Maintain Environmental Health in Family and School: i. To keep the surrounding clean. ii. Proper management of waste produced from house and school. iii. Plantation of trees around the house and school. iv. Proper cleanliness and management of toilet. v. Control of cattle from tress passing into the school premise. vi. Construction of garden at home and school. vii. By preventing the establishment of industries, factories and organizing fair, festivals around the school. 7.2.2 Sources and Causes of Environmental Pollution Change in physical, chemical and biological components of the environment use 179

to occur due to the various kinds of natural and anthropogenic causes. Change occurring in both quantity and quality in the state of those components of the environment is known as environmental pollution. Environmental pollution does not occur itself but happens due to the change in the nature and human activities. Global warming, Volcanic Eruption, Flood, Landslide, Soil Erosion, Earthquake, etc are considered as natural sources of environmental pollution. On the other hand, industrialization, unmanaged urbanization, deforestation, explosion, mining, war, construction work, etc are considered as anthropogenic sources of pollution. Now, human have started exploiting nature ruthlessly. In this context, population growth has become a major factor affecting the environmental situation of the earth. The sources of environmental pollution from both of the nature and human side are explained below: A. Natural Sources In the earth, we can observe change in the temperature time to time. Similarly, some natural occurrence like Volcanic Eruption, Acid Rain, Earthquake, Flood, Landslide, Ozone Layer Depletion, Green House Effect, etc are frequently seen in the Earth. Indeed, these are the environmental pollution causing natural factors. Some aspects that cause pollution from the natural sources are explained below: 1. Change in the Earth Temperature Due to the increase of concentration of carbon dioxide and carbon monoxide and decrease in the proportion of oxygen, there is increase in the temperature of the Earth. In the long term, it results into climate change. The factors like deforestation, burning of plastics, emission of gases from old vehicles, factories, industries, Volcanic Eruption, etc contribute in increasing the temperature Effect of Global Warming of the Earth. In environmental term, it is appropriate to say Global warming. As a result, different environmental problems such as melting of ice in the high Himalaya and polar regions, occurrence of Glacier Lake Outburst Flood (GLOF), Flash Flood in the river, drought, etc increases in the earth. 2. Volcano Volcano is one of the natural disasters. It occurs due to the pressure exerted by the molten substances and gases. Volcano breaks the weak surface of the Earth. The molten substance called magma come out with the great force causes the Volcanic Eruption. Volcano causes Earthquake 180

and Landslide in the affected area. It also destroys life and property along with the physical development structures like road, power station, buildings etc. Consequently, it results into many environmental crises in that area. 3. Earthquake Volcanic Eruption A sudden shaking or series of vibration in the earth’s surface caused by the sudden release of slowly accumulated strain by faulting is called an Earthquake. This vibration is also known as seismic wave, which can be defined as the wave of vibration produced from hypocenter of the Earthquake. The seismic wave move in all direction from hypocenter. Based on the movement of the Earth Damaged by Earthquake surface, Earthquakes are of two types: i.e. Horizontal Earthquake: It is the movement of back and forth of the parts of the Earth. It is more dangerous in comparison to the vertical Earthquake. Vertical Earthquake: It is the movement of up and down of the parts of Earth. It is less dangerous than the horizontal Earthquake. The Earthquake usually begins deep in the Earth. The point within earth surface where seismic waves are produced is called hypocenter. The hypocenter of the Earthquake is always below the surface of the Earth. On the other hand, the point in the earth surface vertically above the hypocenter is called epicenter. The magnitude of Earthquake is more at epicenter than the other places of the surface of the Earth. It plays the role to trigger the incidence of landslide. It destroys the life and property. It may cause serious damage to the roads, houses, bridges and other constructions. It consequently deteriorates all aspects of environment. 4. Flood Flood Hazard The overflow of water in a river or stream is called Flood. The nature of the Flood depends upon the various factors like amount and intensity of rainfall, nature of the soil, vegetation cover and the slope of the land. The amount of Flooding 181

is conditioned by several factors such as deforestation, rainfall, Earthquake, out bursting of glacial lake, global climate change, over grazing and silting. In the context of Nepal and South Asia, monsoon rainfall poses a severe Flood hazards. Some of the important effects of Flood are as follows: It decreases fertility of land by depositing sand, stone, and gravel in fertile land. It also damages roads, bridges, industries, powerhouses and other physical structures including life and public property. At the same time, it causes Landslide and soil erosion. Moreover, it spreads some epidemics like dysentery, typhoid, diarrhea, etc. 5. Landslide The sliding of the soil and rocks downwards on the slope land is known as Landslide, the movement of the soil and rocks downwards occurs due to gravity. Steep sloppy mountains and hills with loosely arranged soil is the major natural factor of Landslide. Similarly, the Earthquake, deforestation and A Devastating Landslide overgrazing may play some role for Landslide. At the same time, the unscientific use of dynamites to blast the hills for the construction of roads dislocate and weaken the land that also may cause Landslide. Landslide eventually destroys the fertile land. It causes the damage of human made infrastructures like road, building, temple, etc. It causes loss of lives of an animals, human beings, etc. As Secondary effect, it causes pollution in the sources of water and rivers. In addition, it causes epidemic disease. Similarly, it causes the destruction of the infrastructure of communicable, electricity, transportation, etc. 6. Ozone Layer Depletion Ozone is a gas that is naturally present in our atmosphere. It is an ionized form of iosxfyoguenndwphreimreareialychatotzwooneremgioolnescuolfetchoenatatminosstphhreeerea(tio.em. sinotfhoexyugpepner(Op3a)r.tOozfotnhee troposphere and stratosphere). The large amount of ozone in the stratosphere is often called ‘ozone layer’. It is a poisonous gas. Though ozone is a poisonous gas it is only the substance present in the atmosphere that has power to check the harmful ultraviolet radiation coming from the sun. The gases like chlorofluorocarbon (CFC), bromine monoxide (BrO), chlorine monoxide(CIO), halons, etc used in the refrigerators, coolers, foam industries, fire 182

extinguishers and other industrial works deplete the ozone layer. These gases bring chlorine and bromine to the stratosphere and eventually cause depletion of the ozone layer. The ultraviolet radiation on the earth surface increases as a result of depletion of the ozone layer. This situation results into the various kinds of health problems such as cancer, skin diseases, eye diseases and damage of immune system. It may also cause reduction in the productivity of plants and animals. Similarly, it may destroy plankton and other microscopic organisms which may ultimately affect fish and other aquatic life. Activity Organize a talk program on natural sources of pollution and their mitigating measures with a panel of experts. B. Anthropogenic Causes/Sources The different kinds of negative human activities have been playing a great role in environmental pollution. Deforestation, war, explosion of weapons, mining, physical construction works, industrialization, unmanaged urbanization, unmanaged solid waste management, unmanaged drainage, unsustainable farming come under these kinds of activities. Such kinds of activities after all become the sources of environmental pollution. At present, human activities have resulted into unlimited exploitation of every bit of natural resources. Unlimited exploitation of the gifts of nature by man causes environmental pollution and eventually it disturbs the delicate ecological balance between living and nonliving components of the biosphere. In this way, the unfavorable conditions created by man himself have threatened the survival of not only man himself but other living organisms too. People establish cement industries, textile industries, brick industries, beverage industries. They manufacture useful things for us. But due to the lack of proper management of those industries we have to take public warning as “Air unfit for breathing!”, “Water unfit for drinking”, “Do not eat fish caught here!” etc. Besides this, there is a large number of industrial waste and emissions particularly poisonous gases in the atmosphere. Due to the lack of culture of pollution control, there has resulted a great problem of gaseous, liquid and solid waste pollution in our country. Similarly, chemical fertilizers and pesticides used by farmers pollute the water sources. As a result, various types of air borne and water borne diseases spread in the country as epidemic diseases. Some of the manmade cause of environmental pollution are explained below: 183

1. Deforestation A Tragic Deforestation Forests have important role in the conservation of the natural environment. Forests are important components of our economy and environment. Besides economy; forest check air pollution and soil erosion. They save the hill-slopes from Landslides. It is believed that forests attract rainfall too. However, the deforestation rate is increasing day by day due to growing demand of timber and other forest products in our country. As a result, forests are fast vanishing from our country. Due to the unabated deforestation, land is becoming drier and natural disasters like Landslides, destruction of natural beauty and reduction on productivity of our cropland are increasing day by day in the country. At the same time, the amount of oxygen is decreasing whereas the proportion of carbon dioxide is in the increasing trend due to the rapid deforestation. Moreover, due to the deforestation emission of green house is also increasing day by day, which may result into the environmental problems such as Global warming and climate change. 2. Mining Various kinds of minerals are deposited in different places of the earth. Those minerals can be used in various purposes in the development of the society and the nation. The government and other concerned organizations are involved in mining of those mineral deposits. If those mining People Working at Coal Mining works are not managed in a proper and systematic way, it happens to cause various forms of environmental pollution. For instance, various kinds of environment related problems like soil erosion, water pollution, air pollution, sound pollution may occur due to the haphazard mining activities. Such activities may spread different kinds of physical and mental health problems like diarrhea, dysentery, typhoid, deafness, cataract, hypertension, and other associated diseases to the human beings. At the same time, the haphazard mining activities may deteriorate the balance of ecosystem of that place and may affect the habitat of wildlife and other biological resources adversely. 184

3. Construction Work The development activities, related to the physical construction are essential to improve people’s living standard. Construction works like road, canal, bridge, damp, building, towers, airports, railways, etc are related to development activities. These construction related works might cause degradation of ecosystems. Various forms of Construction of Hydro Plant construction works like roads, bridge, towers, canals, railways and large buildings without Environment Impact Assessment (EIA) may destroy the agricultural land and ecosystem. At the same time, very fragile wetlands ecosystem are also severely affected by such constructional works. The activities such as construction of housing, roads, pipelines, etc causes habitat loss that ultimately poses threat to species. It also disturbs reproduction and breeding process of the wildlife. The mobility of wildlife becomes gradually narrower due to the destruction, fragmentation, and deterioration of the forest. Moreover, the tendency of exploiting agricultural land for housing and other purposes are also the causes of loss of agricultural land. Such works depletes the resources and deteriorates the natural beauty. Dust particles and unmanaged piling of waste as the byproduct of the construction work makes the environment polluted. Construction of tall buildings in urban areas depletes the aesthetic value of the cultural heritage and its importance. 4. Industrialization Industrialization really helps in the socio-economic development process of the nation. However, lack of advance technology and unsystematic management of industry; it has left several negative effects on the environment. We know that industrial works are directly related to the environment. Though they have various benefits, they create several A Factory environmental implications also. Unmanaged industries pollute environment very severely. Release of solid and liquid waste causes water pollution, air pollution 185

and very often sound pollution too. Consequently, it causes depletion of aquatic and terrestrial flora and fauna. Moreover, it destroys physical environment of the surrounding. Industries established near the residential areas create sound and air pollution which affects human health negatively. 5. War and Explosion A throat cut competition between the countries results into the serious problems like misunderstanding, conflict, dispute and war. The arms and ammunitions such as atom bombs, hydrogen bombs, and other devastating atomic weapons may endanger the existence of human life and survival. It may damage the human civilization, Casualties by Bomb Explosion which is very difficult to restore. The experiment and trial of those explosive and harmful weapons create severe and unprecedented environmental problems. As a result, people have to live paralyzed and risky life where they cannot breathe freely. They cannot enjoy liberty and humanitarian life. War and explosion damages both the natural and cultural environment. Hence, it is also considered as a prominent source of environmental pollution in the present world. 6. Unmanaged Urbanization The haphazard urbanization without urban planning and basic urban facilities can be termed as unmanaged urbanization. Unmanaged urbanization has created various problems as evidenced in the deteriorating environmental conditions of many large crowded cities. The process of urbanization without any plan can Traffic Jam leave the adverse effects on the environment like unhealthy settlement, improper management of drainage and waste, etc. Unplanned urbanization and settlements are the conditions resulted by lack of effective urban planning which results into adverse effects on health, sanitation, security, housing and other aspects of life. As a result, people will be deprived of the minimum facilities like drinking water, health services, transport, electricity, employment, communication, etc. Due to unmanaged urbanization, a large number of people are deprived from the access to employment, health and other enumerable urban facilities. It might increase the 186

possibility of robbery, theft, black marketing, rape, murdering, food adulteration, kidnapping, urban poverty and other many antisocial activities. Among the various municipal problems, the disposal of solid waste and sewage are the most remarkable problems of those urban areas. Activity Organize a debate program on the topic “Natural sources of pollution is more severe compared to anthropogenic sources of pollution” in the class under the guidance of your subject teacher. 7.2.3 Impact of Environmental Pollution on Health It is obvious that people have to involve in different activities in their day to day life. Those human activities bring some environmental problems. Those environmental problems are described below: A. Land Pollution All types of land have their own value in the environment. People throw-out waste materials in the environment. People throw out waste materials such as broken glasses, plastics and other unwanted materials on the land that causes land pollution in the long run. Similarly, the random use of chemical fertilizers, pesticides, insecticides and industrial effluents cause land pollution. Land pollution Haphazard Dumping refers to the degradation of bio-chemical quality of soil due to mixing and dumping and accumulation of waste products on soil. Causes of Land Pollution Disposal of waste materials like broken glasses, plastics, metals, etc Continuous production of the same type of agricultural crops Excessive use of chemical fertilizers, pesticides, insecticides, etc Nuclear explosions Fluorides, Lead and Acid Rain also cause soil pollution Improper disposal of solid and liquid by-products from leather-tanning, industry, paper factory, distillery and hotels also cause land pollution Improper disposals of cans, bottles, aluminium paper, batteries also are the causes of soil pollution in the mountaineering and tourist areas Defecation and urination in open places 187

Some of the effects of land pollution are as follows: ^ Waste that contain Lead, Zinc, Mercury, cadmium, etc produce toxic effect to the living organisms in the soil ^ Pesticides and insecticides manufactured from the harmful chemicals when spread on the crops may cause various diseases to the consumers ^ Excessive use of chemical fertilizer causes soil and water pollution and eventually affects human health ^ Acid Rain and other harmful chemicals destroy the vegetation and organisms in the soil and water ^ It affects the natural beauty and degrades natural and cultural environment ^ It decreases productivity of land B. Water Pollution Rivers, wells, lakes, springs are the sources of water. Human activities pollute water sources. For instance, disposal of solid wastes, improper use of chemical fertilizers, improper management of sewage pollute the water sources. Water pollution can be defined as; Physical, biological and chemical changes of water from its original natural quality due to Pollution in Water Source mixing of harmful pollutants is called water pollution. Causes of Water Pollution ^ Washing clothes and utensils, swimming, in the water resources ^ Direct disposal of solid and liquid waste materials into the water sources ^ Improper use of chemical fertilizers pesticides and insecticides in farming ^ Improper water storage system, corrosion of water pipes, leakage in water pipes ^ Natural causes like Flood, Landslide, Heavy rain, etc ^ Acid rain is also a major cause of water pollution ^ Mixing of discharge from the hotels, hospitals, laboratories, industries without treatment into the water sources Some of the effects of water pollution are as follows: ^ Polluted water spreads various water borne disease like Typhoid, Hepatitis, Diarrhoea, Dysentery, Cholera, etc ^ It causes depletion of aquatic animals ^ It degrades the beauty of water resources ^ Irrigation of agricultural land with polluted water may kill young plants and seedlings ^ Bad smell from polluted water causes air pollution 188

C. Air Pollution Air pollution is mainly caused by man and his activities. Air pollution has no geographical and political boundaries. So, it is also called the global health problem. It can be defined as; an undesirable change in the physical, biological and chemical characteristics of air due to the intrusion (mixing) of pollutants like harmful gases, smoke, dust particles, pathogens, etc. Causes of Air Pollution A Source of Air Pollution ^ Use of automobiles, aircraft, etc ^ Dust particles from untopped roads ^ Smoke from forest fire ^ Volcanic Eruption ^ Harmful gases emitted from industries and vehicles ^ The use of firewood, dried dung and agricultural residues for cooking ^ Burning of plastics and rubber during strikes ^ Improper disposal of solid waste and sewage Some of the effects of air pollution are as follows: ^ Prevalence rate of respiratory disease, eye irritation, allergy increases ^ Concentration of dust particles, Carbon dioxide methane other harmful particles in the atmosphere reduce the visibility of sunlight ^ Concentration of Chlorofluro Carbon (CFC) and Carbon Tetrachloride deplete the Ozone layer ^ Air pollution causes negative impact on the physical and cultural aspects of environment ^ People suffer from Anaemia, COPD, Bronchitis and other various forms of respiratory diseases ^ Threat of Global warming increases D. Noise Pollution Noise pollution refers to the wrong sound in the wrong place at the wrong time. We are living in an increasingly noisy environment. Crowd of people, loudspeaker, means of transportation and machines are the sources of sound. It can be defined as; an unwanted Sources of Noise Pollution and unpleasant sound that is harmful to health and productivity of human health is called sound pollution. 189

Causes of Noise Pollution ^ Unmanaged urbanization and industrialization ^ Automobiles and aircrafts ^ Crowd of the people ^ Sound produced from cement factories, rice mills, grill factories, saw mills, etc ^ Construction of road, buildings, etc ^ Musical instrument played in the concerts Some of the effects of noise pollution are as follows: ^ Loud noise may cause deafness ^ Sound pollution adversely affects digestive system ^ People feel tired and affects daily activities ^ Blood pressure increases ^ It also causes sleeplessness (Insomnia) problem ^ It interferes with speech communication ^ It may cause anxiety and frustration to people ^ It also causes irritation and lack of concentration Activity Organize an essay writing competition on causes, impacts and controlling measures of different types of environmental pollution in the context of urban areas of Nepal in your school with the help of your subject teacher. 7.2.4 Mitigating Measures of Environmental Pollution At present, environmental pollution has become a serious and major issue in the world. So, the whole world including Nepal have made their commitment to control environmental pollution through all possible measures. In this context, the government agencies, NGOs, INGOs and different community level local organizations have been conducting pollution mitigating programs. In this situation, there must be rational utilization of resources to fulfill present needs without hampering the future needs. Moreover, we should not forget that environmental pollution can be controlled by addressing the issues of poverty, unemployment, food scarcity and backwardness of the nation. A. Measures to Control Land Pollution Different measures can be adopted to control land pollution. Some of them are as follows: ^ Biodegradable waste like residue of vegetables, weeds, left over grass, etc can be used for compost manure 190

^ Practise reuse and recycling methods for paper, plastics, beverage bottles, metals, etc ^ Over use of chemical fertilizers, pesticides, insecticides, etc should be controlled ^ Farmers should be encouraged to use organic or compost manure ^ Use of polythene materials should be controlled ^ Sewage from industries, hotels, laboratories should be treated before disposal ^ Afforestation should be done in the open and barren land ^ There should be proper management of solid waste ^ Discourage the use of nuclear weapons ^ Education and awareness campaign about the causes, impact and control measures of land pollution B. Measures to Control Water Pollution Different measures can be adopted to control water pollution. Some of them are as follows: ^ Waste water from industries, hotels, hospitals, etc should be properly treated before discharging outside ^ Awareness programmes should be carried out on the effects of water pollution on public health ^ Discourage the open urination and defecation and encourage to use toilets ^ Establishment of water recycling and purification plants in industries, hotels and laboratories ^ Regular supervision and maintenance of water supply pipes and storage system ^ Encourage tree plantation and discourage deforestation to prevent Flood and Landslide C. Measures to Control Air Pollution Different measures can be adopted to control air pollution. Some of them are as follows: ^ Education and awareness campaign about the ill effects of air pollution should be conducted in massive scale ^ Exploration and utilization of alternative sources of energy instead of conventional sources like animal dropping, firewood, kerosene, etc should be done in time ^ Old automobiles should be replaced by the new eco-friendly vehicles ^ Tree plantation on the road side as well as afforestation programme should be done through community participation ^ There should be proper management of industries 191

^ There should be proper management of solid waste and sewage in the urban areas ^ The government should enforce the environment protection law and regulation for the protection of environment D. Measures to Control Sound Pollution Different measures can be adopted to control sound pollution. Some of them are as follows: ^ Education and awareness campaign about noise pollution issues ^ Proper management of urbanization, industrialization and transportation system ^ Establishment of bus parks, railway stations and airports far away from the residential areas ^ Plantation of trees on the road sides and surrounding the houses and factories ^ The workers who work in the noisy places should be given earplugs and ear muffs ^ Silence zone must be maintained nearby school, hospitals, college, etc ^ Unnecessary volume of loud speaker at public places should be controlled ^ Vehicles should be prohibited to use unnecessary horns Activity Prepare a speech on “Problems and Challenges of unmanaged Urbanization in the context of Nepal” and perform it at the school assembly. 7.3 Solid Waste Management Unmanaged solid waste disposal is one of the main causes of environmental degradation of localities. Solid waste management problem is growing day by day especially in urban areas of the country. In rural areas, the higher proportion of generated waste is biodegradable and natural system is able to absorb it. Therefore, the problem of solid waste management is not yet felt in rural areas of our country. On the other hand, increasing population density is the leading cause of solid waste management problem in urban domain in Nepal. Here, solid waste management can be defined as: Solid waste management means handling process of solid waste materials from generating at source to disposal. It is noted that people’s cooperation is the vital aspect in the solid waste management activities. At the same time, habits and attitudes of the inhabitants affect highly in the waste management activities. According; to the Municipal Act, 1989 AD., the respective Municipality is the main responsible institution for the cleaning localities and waste management. 192

Waste should be managed at the place from where it generates. More wastes are produced in the city areas because of dense population than rural areas. Hence, proper managements of waste is essential to save the environment of these localities. The proper management of solid wastes connotes different steps from collection of wastes generated from different sources to composting and disposal of the waste materials in a safe manner. A. Sources of Solid Waste The places, institutions, organizations, and sites that generate solid wastes are known as the sources of solid waste. The nature of the waste depends upon the sources of those wastes. For instance, the waste generated from the agricultural field and commercial places are less hazardous in comparison to the waste produced from the hospitals and its pathology and labs. Some of the major sources of solid wastes are explained below: 1. Domestic Sources Domestic wastes are those wastes, which are generated from household. They contain a variety of materials thrown out from homes. These wastes include many substances and materials like peels of fruits and vegetables, packing materials, pieces of glasses, food waste, paper, cardboard, plastics, textiles, yard wastes, wood, glass, metals, ashes, cloth, waste paper, glass bottles, polythene bags, waste metals, etc. 2. Industrial Sources The wastes generated from the industries like chemical plants, manufacturing and refinery industries come under industrial waste. The waste paper, plastics, cardboard, packaging paper, damaged machine parts, cans, bottle, polythene bags, rubbish, scrap metals, rubber, glass, wood, paints, dyes, etc are generated from the industries. 3. Commercial Sources The wastes that are generated from the shops, vegetable markets, hotels, offices and institutions are known as commercial waste. These wastes include packaging materials, plastics, cardboard, waste paper, cans, bottle, polythene bags, rotten fruits and vegetables, etc. 4. Institutional Sources Schools, colleges, hospitals, prisons, government offices, and religious sites are considered as the solid waste generating places. The institutional wastes include plastics, cardboard, waste paper, packaging material, cans, bottle, polythene bags, damaged furniture, food wastes, empty pens, etc. 193

5. Constructional Sources The waste materials generated from the construction and demolishing of buildings, construction of road, paving the pipes of drinking water and sewage are called construction related waste. Those wastes include the construction and demolition materials like concrete, sand, bricks, wood, debris, pieces of iron rods, etc. 6. Hospital Sources Hospitals, nursing homes, polyclinics, laboratories and pathology, generate hazardous waste. Those wastes include infectious items such as amputated body parts, body fluids, cultures of pathogens, anatomical wastes, infectious wastes, etc. They also include scalpels, needles, bandages and other wastes from operating theatres and laboratories. 7. Agriculture Sources The wastes are also generated from the places like orchards, vineyards, dairies, fishponds, poultry and cattle farm. Spoiled food wastes, agricultural wastes, rotten vegetables, spoiled tea leaves, dry leaves, weeds, damaged fertilizers, pesticides, and insecticides come under the waste of this kind. B. Classification of Solid Waste According to the nature, the solid waste can be classified primarily into three groups such as organic (biodegradable/ decomposable) waste, inorganic waste (non- biodegradable/non- decomposable) waste and disposable or landfill waste. Classification of Solid Waste Organic Inorganic Land fill Waste Waste Waste Vegetable Residue Broken Glasses Disposed Mineral Water Bottles Rotten Fruits Torn out Polythene Bags Film Reels Left Over Food Broken Plastic Utensils Weeds Discarded Gifts Wrappers Sludge Metal Pieces Broken Ceramics Paddy Husk Damaged Computer Parts Damaged Parts of Vehicles etc. Discarded Laminated Papers Dead Animals etc. Biscuits & Chocolate Wrappers etc. Fig: 7.1 Classification of Solid Waste 1. Organic or Decomposable Waste All the biodegradable solid wastes are known as organic solid wastes. Agricultural residues, weeds, rotten fruits, vegetable residue, leftover food, dead animals, dung 194

and sludge, etc are the examples of organic solid wastes. This kind of solid wastes occupies about 70 percent of the total quantity of solid wastes in our localities. These wastes can be used for composting. 2. Inorganic or Indecomposable Waste All the non-biodegradable wastes which do not contain carbon compound are called inorganic solid wastes. Turn out plastics, Pieces of metals, broken glasses, disposed film reels, discarded wrapping papers, etc are the examples of inorganic solid wastes. This kind of solid wastes occupies about 20 percent of the total volume of generated solid waste. 3. Disposable Waste (Land Fill Wastes) The solid wastes which can neither be used for composting nor be utilized for reuse and recycling are considered as disposable or land fill wastes. Disposed laminated paper, film reel, wrapping paper, ceramics, etc are the examples of disposable wastes. This type of waste materials contains about (5%) in the total generated solid wastes. C. Measures of Solid Waste Management Waste should be managed at the place from where it generates. We can live a healthy life through proper management of waste in our day to day activities. Proper management of waste makes environment in proper order. The waste can be managed in different ways according to their respective nature, which are explained below: 1. Management Methods of Solid Waste a. Collection Methods of Solid Waste Collection, transfer and proper disposal of solid wastes should be done for the proper management of solid waste. Proper collection of solid waste from all the possible areas of locality is the first step in solid waste management system. Various methods can be applied in operation for the collection of solid waste. Some of them are mentioned below: i. Community Method In this method, huge size metal containers are placed at different corners in the community. People from every house put the waste materials into the container nearest to them. When the containers are filled up with the wastes, they are carried to the land fill site for disposal. ii. Block Method In this method, vehicles are used to collect solid wastes. Such vehicles go through the fixed route and stope at fixed stoppages for the convenience of people. When 195

the vehicles are moving they give siren to the people for information. Then people come to the fixed stoppage and put wastes into the vehicle. When the vehicle is filled up with the wastes, it is carried to the dumping site for disposal. iii. Door to Door Method It is also one of the popular methods for the collection of solid wastes. In this method, waste collecting vendor visits each house and collects waste materials keeping in a waste carrier. The waste collector carries such waste materials to a fixed place for disposal. Then vehicles may take that wastes to the dumping site. b. Disposal Methods of Solid Waste i. Open Dumping Dumping of solid waste generated from household, offices, commercial places, and community is considered as open dumping. Generally, we happen to see open dumping of solid waste at the public places such as side of the road, chowk, at the side of the main market area, Bus Park, open field, etc. People use to Open Dumping throw garbage, rubbish and other kinds of municipal wastes in those places. It is an old traditional dumping method. This method has been proved to be the most unhygienic method of solid waste management. It causes various types of pollution such as land pollution, water pollution and air pollution. Moreover, it also spreads bad odour and various types of communicable diseases in the surrounding area. So, WHO has band this method of dumping. ii. Sanitary Landfill It is the most hygienic method of solid waste disposal where wastes are dumped into the sanitary landfill site. Sanitary landfill site is the scientifically prepared trench, which covers a larger area for dumping of solid wastes. In a sanitary landfill, garbage is spread out in thin layers and compacted them with the help Sanitary Landfill Site of rollers or bulldozers and toping over the layer with soil every day. In the modern landfills, the bottom is covered with an impermeable liner, usually several layers 196

of clay, thick plastic and sand. The liner protects the ground water from being contaminated due to percolation of leachate. Leachate from bottom is pumped and sent for treatment. When landfill is full, it is covered with clay, sand, gravel and top soil to prevent seepage of water. Methane produced by anaerobic decomposition from this site can be collected and used as fuel. It is the best landfill method for human health and sanitation perspective. There are three methods in sanitary landfill, which are mentioned below: e Trench Method e Ramp Method e Area Method iii. Burial In this method, a pit of 4-6 feet diameter and about 2 meters depth is dug for dumping purpose. The pit size depends on the quantity of the waste. This method is commonly practiced for short-term camping activities. It is also equally appropriate for a small family. After making the pit, waste is dumped everyday and it is topped with a thin layer of soil. When the pit is filled up, it is covered with thick layer of the soil. Moreover, a new pit can be prepared for the next time. It is a simple and cost effective disposal method. iv. Incineration The term incinerates means to burn something until nothing is left but ashes. It is a hygienic way of disposing solid waste. It is suitable if waste contains more hazardous material and organic content. Burning of solid wastes is not widely recommended since it causes air pollution by releasing harmful gases. However, some wastes are very hazardous and sensitive, so that waste such as used syringes, catheters, gloves, needles Burning of harmful waste in incinerator and other hazardous by products should not be dumped into the landfill site. Thus, such hazardous waste by-products need to be burnt in the incinerator. In this method, the solid wastes are burnt in a furnace called ‘incinerator’. It is constructed of heavy, well-insulated materials so that it does not give off extreme amounts of external heat. Combustible substances such as rubbish, garbage, dead organisms, used syringes, catheters, gloves, needles and other hazardous by products are burnt in more than 700°C temperature without emitting harmful smoke. 197

Activity Observe the solid waste management practice and behaviour of the people in your locality. Ask them about more effective management methods of the waste and its impact on environmental health. Then prepare a report and present it in the class under the guidance of your subject teacher. c. Composting Methods of Organic Solid Waste Composting is a biological process in which microorganisms, mainly fungi and bacteria, convert degradable organic waste into humus like substance. This finished product, which looks like soil, is high in carbon and nitrogen and is an excellent medium for growing plants. Of the total generated municipal wastes, the biodegradable waste materials occupy more than (75%). Composting Aerobic method of composting practice has been started perhaps with the beginning of agrarian society. Compost manure can be prepared by using biodegradable waste materials like animal dung, plant residue, grasses, sludge, etc. Aerobic or anaerobic bacteria decompose the waste materials and finally convert them into compost manure in this process. Pits of different size can be made for composting, according to the quantity of waste materials. Some of the composting methods are mentioned below: i. Aerobic Method The composting method in which aerobic bacteria are activated for compost manure preparation through aeration (passing air) into the manure pit is called aerobic method. In this method, a pit of desirable size is made in the earth. Decomposable wastes of all kinds are put into the pit. It can take some days or even months to be filled up with the wastes. When the pit is full with the wastes, that waste should be turned upside down once in a week. It helps to turn the waste of upper level at the bottom and the waste of bottom at the upper level. Then it helps to decay the waste material of the upper level, which are raw. This should be done repeatedly every week, which helps the waste decaying faster. Compost manure can be prepared within 3 to 4 months under this method. ii. Anaerobic Method The composting method in which anaerobic bacteria are activated for composting by not allowing aeration facility into the pit is called anaerobic method. In this method, as in the aerobic method, a pit of desirable size is made in the earth. After 198

that, all kinds of biodegradable waste materials are kept into that manure pit. When the pit is full with the waste, it should be covered with a thick layer of soil at the top. When the pit is completely closed, then anaerobic bacteria multiply its population, begin its decomposition process over the wastes, and increase the temperature of the pit. It takes the period of 4 to 6 months for compost preparation under this method. Difference between Aerobic and Anaerobic Composting Methods Aerobic Composting Method Anaerobic Composting Method • The compost manure prepared by • The compost manure prepared in the the aeration process is called aerobic absence of aeration facility is called composting method. anaerobic composting method. • In this method, aerobic bacteria • In this method, anaerobic bacteria decompose the waste materials. decompose the waste materials. • In this method, aeration facility is • In this method, aeration facility is not allowed in the manure pit. allowed in the manure pit. • The pit is less stinky due to aeration. • The pit is more stinky due to the absence of aeration. • The waste is turned upside down • The pit is covered with a thick layer periodically once in a week. of soil when it is filled up with the waste. • It takes generally 3-4 months for • It takes about 4-6 months for composting. composting. iii. Mechanical Method In this method, the biodegradable waste materials are cut into small pieces with less than two inches. Then that waste materials are mixed up with waste, sludge and wastewater to maintain proper moisture of the wastes. At the same time, paddy husk, straw or saw mill husk also should be added in the waste materials in essential amount to balance C: N Ratio (Carbon Nitrogen Ratio). Similarly, the temperature should be made stable within the range of 22°C to 30°C (neither too cold nor too hot) for fast composting process. Compost can be prepared within one or two month under this composting method. iv. Vermi Composting Method Vermi-composting has become very popular in the last few years. In Greek word, vermi means earth worm. Hence, the technology in which compost manure is prepared with the help of vermis (a particular species of Earthworms) is called vermi-composting method. A bamboo basket, a small amount of animal dung, mud, straw and a small number of Vermis are required to prepare compost manure through this method. At first, a two inches layer of straw bedding should be 199

managed at the bottom of the basket. After that, animal dung and mud layer should be managed over the straw bedding. Then small number (200-500) of Vermis can be released over the bedding. Then, the biodegradable wastes like vegetable residue, leftover food and rotten fruits can be kept in the basket as per the requirement of those vermis. Vermicomposting method The cast of the Vermis can be collected in 2 months duration continuously. It is the best kind of compost for the plants. These vermis are photosensitive so always keep them away from the direct sunlight and cover the basket’s lid with black cloth. Activity Observe the methods that are applied by your family to manage organic or decomposable solid waste. Prepare an individual report based on your finding and present it in the class. 2. Solid Waste Management Principles Solid waste management is accepted as a growing issue that has caused environmental pollution especially in the urban areas. According to the survey report of IUCN 1997 AD, solid waste generation per head per day for Kathmandu Metropolitan City was 0.56 kg. At the same time, solid waste generation for all municipalities in average was estimated to be 0.25 kg. per day per head. According to this estimation, the total daily waste generation is more than 1,000 metric tons daily from the urban areas of the country. So, for the proper management of the solid waste, we should follow the principle of solid waste management. It is also called “3R principle”. They are: Reduction, Reuse and Recycle of waste materials. a. Reduction This principle gives emphasis on less use of things and generating less quantity of wastes. If usage of raw materials is reduced, the generation of waste also gets reduced. For this, we can develop our habits like using jute and paper bags while buying goods from the market to replace polythene bags, by not cooking more food than our requirement. Similarly, we can buy milk from the dairy in our own pot or utensils rather than using polythene. These are the examples of reduction principle. If majority people follow this principle, we can preserve the natural resources in one hand and able to control environmental pollution in other hand. 200