LAND AND SOIL RESOURCES Chapter 1

Transcription

1 Humans through technology and institutions transform things available with nature. Resources are of two types natural and human. Resources can be classified in the following ways (a) On the basis of origin biotic and abiotic (b) On the basis of exhaustibility renewable and non-renewable (c) On the basis of ownership individual, community, national and international (d) On the basis of status of development potential, developed stock and reserves. The oceanic area up to 12 nautical miles from the coast line is called territorial waters of a country. The area up to 200 km from the coast line in which the country has the exclusive rights to exploit the natural resources is the exclusive economic zone. It includes territorial waters in it. Resource planning is the technique or strategy for the judicious use of resources in a country. Sustainable economic development means development should take place without damaging the environment, and development in the present should not compromise with the needs of the future generations. Agenda 21 is the declaration signed in 1992 at the UNCED, Rio de Janeiro, Brazil. It aims at achieving global sustainable development. It is an agenda to combat environmental damage, poverty, disease through global co-operation. Land supports natural vegetation, wild life, human life, economic activities, transport, and communication systems. About 43 per cent of the land area is plain, which provides facilities for agriculture and industry. Mountains account for 30 per cent of the total surface area of the country. They ensure perennial flow of some rivers; provide facilities for tourism and ecological aspects. About 27 per cent of the area of the country is the plateau region. It possesses rich reserves of minerals, fossil fuels and forests. Islands are less than 1 per cent of the area of the country. They provide opportunities for sea trade, tourism, and fish catch. Net sown area is over 80 per cent of the total area in Punjab and Haryana. Due to gentle sloping lands covered with fertile alluvial soils and black soils, climate favours cereal cultivation, good irrigation facilities, high population pressure. Net sown area is less than 10 per cent in Arunachal Pradesh, Mizoram, Manipur and Andaman Nicobar Islands because of mountainous areas, lack of irrigational facilities, infertile soils, low density of population, etc. The use of land is determined both by physical factors such as topography, climate, and soil types as well as human factors such as population density, technological capability and culture and traditions etc. If a land is left uncultivated for more than 5 agricultural years it is called Culturable waste land. If a land is left uncultivated for the past 1 to 5 agricultural years it is called Other than current fallow. If a land is left without cultivation for one or less than one agricultural year it is called Current fallow. Net sown area is the total area sown with crops and orchards. Area sown more than once in the same year is counted only once. Suryaveer Singh Page 1 of 9

2 Area sown more than once in an agricultural year plus net sown area is known as gross cropped area. Barren Land: This includes all land covered by mountains, deserts, etc. Land which cannot be brought under cultivation except at an huge cost is classified as unculturable land. The top most layer of the earth crust which is composed of organic and non-organic matter is called soil. Soil is renewable natural resource. The soil is a living system. 33 % of geographical area should be under Forest in the country according to the National Forest Policy Alluvial soils are the most widely spread and important soil of our country. Alluvial soils are found in the entire northern plains, Rajasthan and Gujarat, eastern coastal plains, deltas of the Mahanadi, Godavari, Krishna and Kaveri rivers. Duars, Chos and Terai are the Piedmont plains where alluvial soils are coarse. According to their age alluvial soils are of two types: old alluvial (Bangar) and new alluvial (Khadar). Black soils are also known as regur soils or cotton soils. Black soils develops on Basaltic lava rocks. Black soils are found in the Deccan trap (Basalt) region of Deccan plateau, the plateaus of Maharashtra, Madhya Pradesh and Chhattisgarh. Red soil develops on crystalline igneous rocks. Red and yellow soils are found in the eastern and southern parts of the Deccan plateau, the Western Ghats. The laterite soil develops due to intense leaching in areas with high temperature and heavy rainfall. Laterite soils are found in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, and the hilly areas of Orissa and Assam. The denudation of the soil cover and subsequent washing down is described as soil erosion. When the running water cuts through the clayey soils and makes deep channels it is called gullies. The land becomes unfit for cultivation and is known as bad land. In the Chambal basin such lands are called ravines. Sometimes water flows as a sheet over large areas down a slope. In such cases the top soil is washed away. This is known as sheet erosion. Wind blows loose soil off flat or sloping land known as wind erosion Q.1 Define the term resources. Ans. Everything available in our environment which can be used to satisfy our needs, provided, it is technologically accessible, economically feasible and culturally acceptable can be termed as Resource Q.2 Describe the type of resources classified on the basis of origin. Ans. On the Basis of Origin: 1. Biotic Resources: These are obtained from biosphere and have life such as human beings, flora and fauna, fisheries, livestock etc. 2. Abiotic Resources: All those things which are composed of non-living things are called abiotic resources. For example, rocks and metals. Suryaveer Singh Page 2 of 9

3 Q.3 Describe the type of resources classified on the basis of exhaustibility. Ans. On the Basis of Exhaustibility 1. Renewable Resources: The resources which can be renewed or reproduced by physical, chemical or mechanical processes are known as renewable or replenishable resources. The renewable resource may further be divided into continuous or flow such as wind, water etc. and biological such as forest and wildlife. 2. Non-Renewable Resources: These resources take a very long geological time (millions of years) to form. Some of the resources like metals are recyclable and some like fossil fuels cannot be recycled and get exhausted with their use. Q.4 Describe the type of resources classified on the basis of Ownership. Ans. On the Basis of Ownership 1. Individual Resources: These resources are owned privately by individuals. For example farm land owned by farmers, urban people own plots, houses and other property. 2. Community Owned Resources: These resources are available to all the members of the community. For example the village common land for grazing, burial, village ponds, public parks, picnic spots, playgrounds are available to all the people living there. 3. National Resources: All the minerals, water resources, forests, wildlife, land within the political boundaries and oceanic area upto 12 nautical miles (19.2 km) from the coast are included in national resources. 4. International Resources The oceanic resources outside 200 km of the Exclusive Economic Zone belong to open ocean and no individual country can utilise these without the agreement of international institutions. Q.5 Describe the type of resources classified on the basis of status of development. Ans. On the Basis of the Status of Development 1. Potential Resources: Resources which are found in a region, but have not been utilized are called potential resources. For example, wind and solar energy is abundant in Rajasthan and Gujarat but so far these have not been developed properly. 2. Developed Resources: Resources which are surveyed and their quality and quantity have been determined for utilization is called developed resources. The development of such resources depends on technology and level of their viability. 3. Stock: Resources which have the potential to satisfy our needs but human beings do not have the appropriate technology to use these, are included among stock. For example, inflammable gases; hydrogen and oxygen are compounds of water, which can be used as a source of energy. But we do not have the required technical know-how to use them for this purpose. Hence, it can be considered as stock. 4. Reserves are the subset of the stock, which can be put into use with the help of existing technical know-how but their use has not been started. The water in the dams, forests etc. are a reserve which can be used in the future. Q.6 Mention the major problems which has arisen due to indiscriminate use of resources. Ans. Human beings has used resources indiscriminately and this has led to the following major problems. 1. Resources have depleted due to the greed of few individuals/countries. 2. Resources have accumulated in few hands, which, in turn, divided the society into two segments i.e. haves and have nots or rich and poor. Suryaveer Singh Page 3 of 9

4 3. Indiscriminate exploitation of resources has led to global ecological crises such as, global warming, ozone layer depletion, environmental pollution and land degradation. Q.7 Why resource planning is necessary for country like India? Ans. Resource planning is necessary due to - i. An equitable distribution of resources is essential for a sustained quality of life and global peace. ii. The large diversity in the availability of resources in India. a. For E.g. We are rich in metallic minerals but deficient in non-metallic minerals. iii. Some regions which are rich in certain types of resources but are deficient in some other resources. a. For E.g. The state of Rajasthan is very well endowed with solar and wind energy but lacks in water resources. b. Arunachal Pradesh has abundance of water resources but lacks in infrastructural development. iv. Some regions are self sufficient in resources while others are have acute shortage of vital resources. a. For example, the states of Jharkhand, Chhattisgarh and Madhya Pradesh are rich in minerals and coal deposits. b. While, The cold desert of Ladakh is deficient in water, infrastructure and some vital minerals. Q.8 Explain the three stages of resource planning in India. Ans. Resource planning is a complex process which involves: (i) First step is identification and making inventory (list) of resources found across the regions of the country. This involves surveying, mapping and qualitative and quantitative estimation and measurement of the resources. (ii) Second step is developing a planning structure which has appropriate technology, skill and institutional set up for implementing the resource development plans. (iii) Matching the resource development plans with overall national development plans. Q.9 Mention three factors on which the development of resource depend. Ans. In India resource development involve i. The availability of resources, ii. The availability of technology, iii. The quality of human resources, iv. The historical experiences of the people. Q.10 Explain why some regions are resource rich but are economically backward? Explain why some regions are resource poor but are economically developed? Ans. It is because of the following two reasons:- 1. The eastern states are economically backward even when they have vast resource. It is because they do not have appropriate technology and institutions to use the available resources profitably. 2. Mere availability of resources does not guarantee economic development. For the development it is necessary to have good quality of human resources. 3. Rich states are capable of importing resources from outside therefore some states which are poor in resources are more developed. Suryaveer Singh Page 4 of 9

5 Q.11 Why resource conservation is important? Ans. Resource conservation is important because - 1. Resources are vital for any developmental activity. 2. Irrational consumption and over-utilisation of resources has lead to socio-economic and environmental problems. 3. The greedy and selfish individuals and exploitative nature of modern technology has caused depletion of resources at the global level. 4. To overcome these problems, resource conservation at various levels is important Self Activity 1 A.1 Study the diagram showing Land Use patterns and answer the following questions: i. What is the percentage of land under: a. forests, - b. current fallow land, - c. net sown area, - d. pastures and grazing land - e. tree crops, - f. Barren and waste land, - g. Land put to non agricultural usesh. culturable waste land, - i. Other than current fallow lands. - ii. Which type/types of land use shows an increase/decrease during 1960 to 2002? iii. What does low area under permanent pastures indicates? (Hint: large scale cultivation, high population pressure, huge cattle population) iv. What are fallow lands? How much is total cultivated area if the fallow land is included under cultivated area? Why fallow lands are decreasing? (Hint: left uncultivated, poor quality soils, the cost of production) 54% v. What is the desired percentage of forest area essential for maintenance of the ecological balance in India? How are forests helpful? (Hint: livelihoods of people) vi. What are waste lands & land put to non-agricultural uses? vii. What is main cause of land degradation in India? (Hint: Continuous use of land, no conserve and manage) Self Activity 2 Study the figure showing waste lands and answer the following questions: i. Below are given in List A the names of different waste lands of India and in List B the percentages of waste lands. Write against each waste lands, the relevant percentage of it. LIST A (i) Water eroded area, (ii) forest eroded area (iii) saline & alkaline land and (iv) Wind eroded area. LIST B 10%; 28%; 6% and 56% ii. iii. Which type of waste land is largest of all types? Mention its percentage. Why this type of wasteland largest in all types. Give one reason Suryaveer Singh Page 5 of 9

6 Q.12 Describe the natural as well as human causes of land degradation in India. Ans. The natural causes are: i. Erosion caused by running Water such as streams and rivers in hilly areas. ii. Depletion of forests. iii. Increase in salinity & alkalinity of land due to water logging and droughts. iv. Erosion caused by the wind in semi-arid and arid areas. The human factors are: i. Mineral processing activities: - The mineral processing like grinding of limestone for cement industry and calcite and soapstone for ceramic industry generate huge quantity of dust in the atmosphere. It retards the process of infiltration of water into the soil after it settles down on the land. ii. Industrial activities: - In recent years, industrial effluents as waste have become a major source of land and water pollution in many parts of the country. iii. Mining activities: - Mining sites are abandoned after excavation work is complete leaving deep scars and traces of over-burdening. iv. Deforestation: - In states like Jharkhand, Chhattisgarh, Madhya Pradesh and Orissa deforestation due to mining have caused severe land degradation. v. Overgrazing: - In states like Gujarat, Rajasthan, Madhya Pradesh and Maharashtra overgrazing is one of the main reasons for land degradation. vi. Over irrigation: - In the states of Punjab, Haryana, western Uttar Pradesh, over irrigation is responsible for land degradation due to water logging leading to increase in salinity. Q.13 Describe various measures to solve the problems of land degradation in India. Ans. There are many ways to solve the problems of land degradation. i. Afforestation and proper management of grazing can help to some extent. ii. In dry and arid areas: - Planting of shelter belts of plants, control on over grazing, stabilisation of sand dunes by growing thorny bushes are some of the methods to check land degradation. iii. In industrial and suburban areas: - Proper management of waste lands, control of mining activities, proper discharge and disposal of industrial effluents and wastes after treatment can reduce land and water degradation. Q.14 Describe the factors which control the formation of soil. Ans. A number of factors contribute to the soil formation and fertility. i. Parent rocks: - the rock on which the soil is formed decomposes and disintegrates under the processes of weathering. The characteristics of rocks influence the characteristics of soils. For example Black soils are formed on lava rocks and Red soils are formed on iron oxide rich rocks. ii. Climate: - climate influence the rate of weathering of rocks and type of vegetation, thus these influence the characteristics of soils. iii. Slope: - the nature of relief and slope influence the accumulation of soils. Mountains have thin soil cover but the plains have thick soil cover. iv. Time: - time provides maturity to the soil. v. Various forces of nature such as change in temperature, actions of running water, wind and glaciers, activities of decomposers etc. contribute to the formation of soil. vi. Chemical and organic changes which take place in the soil are equally important. Suryaveer Singh Page 6 of 9

7 Q.15 Name the different types of soils found in India. Ans. the different soils found in India are: i. Alluvial soils ii. Black soils iii. Laterite soils iv. Red and yellow soils v. Forest and mountainous soils vi. Arid soils. Q.16 Describe any four important characteristics of alluvial soils. Ans. Important characteristics of alluvial soil are: These soils have been deposited by three important Himalayan river systems the Indus, the Ganga and the Brahmaputra. The alluvial soil consists of various proportions of sand, silt and clay. In the upper river valleys alluvial soil particles are bigger in size. Such soils are common in piedmont plains such as Duars, Chos and Terai. According to their age alluvial soils are of two types: old alluvial (Bangar) and new alluvial (Khadar). Alluvial soils as a whole are very fertile. Mostly these soils contain adequate proportion of potash, phosphoric acid and lime which are ideal for the growth of sugarcane, paddy, wheat and other cereal and pulse crops. Due to its high fertility, regions of alluvial soils are intensively cultivated and densely populated. Soils in the drier areas are more alkaline and can be productive after proper treatment and irrigation. Q.17 Differentiate between Bangar soils and Khadar soils. Ans. The differences are: - a. The bangar soils are old alluvium whereas the khadar soils are new alluvium. b. The bangar soil has higher concentration of kanker nodules than the Khadar. c. Khadar soil has more fine particles and is more fertile than the bangar. Q.18 Describe any four characteristics of black soil found in India. Ans. Important characteristics of black soils are: a. The black soils are made up of extremely fine i.e. clayey material. b. They are well-known for their capacity to hold moisture. c. In addition, they are rich in soil nutrients, such as calcium carbonate, magnesium, potash and lime. These soils are generally poor in phosphoric contents. d. They develop deep cracks during hot weather, which helps in the proper aeration of the soil. e. It is believed that climatic conditions along with the parent rock material are the important factors for the formation of black soil. f. These soils are sticky when wet and difficult to work on unless tilled immediately after the first shower or during the pre-monsoon period. Suryaveer Singh Page 7 of 9

8 Q.19 Describe any four characteristics of red and yellow soil found in India. Ans. Important characteristics of red and yellow soils are: a. Red soil develops on crystalline igneous rocks in areas of low rainfall. b. These soils develop a reddish colour due to diffusion of iron in crystalline and metamorphic rocks. c. It looks yellow when it occurs in a hydrated form. d. They are found in parts of Orissa, Chhattisgarh. Q.20 Describe any four characteristics of Laterite soil found in India. Ans. Important characteristics of Laterite soils are: a. Laterite has been derived from the Latin word later which means brick. b. The laterite soil develops in areas with high temperature and heavy rainfall. c. This is the result of intense leaching due to heavy rain. d. Humus content of the soil is low because most of the micro organisms, particularly the decomposers, like bacteria, get destroyed due to high temperature. e. Laterite soils are suitable for cultivation with adequate doses of manures and fertilizers. f. After adopting appropriate soil conservation techniques particularly in the hilly areas of Karnataka, Kerala and Tamil Nadu, this soil is very useful for growing tea and coffee. g. Red laterite soils in Tamil Nadu, Andhra Pradesh and Kerala are more suitable for crops like cashew nut. Q.21 Describe any four characteristics of arid soil found in India. Ans. Important characteristics of arid soils are: a. Arid soils range from red to brown in colour. b. They are generally sandy in texture and saline in nature. c. In some areas the salt content is very high and common salt is obtained by evaporating the water. d. Due to the dry climate, high temperature, evaporation is faster and the soil lacks humus and moisture. e. The lower horizons of the soil are occupied by Kankar because of the increasing calcium content downwards. The Kankar layer formations in the bottom horizons restrict the infiltration of water. f. After proper irrigation these soils become cultivable as has been in the case of western Rajasthan. Q.22 Describe any four characteristics of forest soil found in India. Ans. Important characteristics of forest soils are: a. These soils are found in the hilly and mountainous areas where sufficient rain forests are available. b. The soils texture varies according to the mountain environment where they are formed. c. They are loamy and silty in valley sides and coarse grained in the upper slopes. d. In the snow covered areas of Himalayas, these soils experience denudation and are acidic with low humus content. e. The soils found in the lower parts of the valleys particularly on the river terraces and alluvial fans are fertile. Suryaveer Singh Page 8 of 9

9 Q.23 State how is the balance between the soil formation and soil erosion get disturbed? Explain the factors which cause soil erosion. Ans. This balance is disturbed due to human activities like a. deforestation, b. over-grazing, c. construction and mining, d. Defective methods of farming: Ploughing in a wrong way i.e. up and down the slope form channels for the quick flow of water leads to soil erosion. It is also disturbed due to natural forces like: a. Wind, b. Glacier and c. Running water leads to soil erosion. Q.24 Explain the different methods of controlling soil erosion. Ans. Some of the methods of controlling soil erosion are: a. In Hilly areas: Ploughing along the contour lines can slow down the speed/flow of water down the slopes. This is called contour ploughing. Steps can be cut out on the slopes making terraces. Terrace cultivation restricts erosion. Western and central Himalayas have well developed terrace farming. b. Agricultural regions: Large fields can be divided into strips. Strips of grass are left to grow between the crops. This breaks up the force of the wind. This method is known as strip cropping. c. Dry areas: Planting lines of trees to create shelter also works in a similar way. Rows of such trees are called shelter belts. These shelter belts have contributed significantly to the stabilisation of sand dunes and in stabilising the desert in western India. Suryaveer Singh Page 9 of 9