Land Resources
(Photo Source: Internet)
LAND RESOURCES ASSAM
The ‘land’ is a very precious gift of nature. His relatively thin cover on the continental surface serving as a medium for plant growth is a product of thousands and million year’s natural activity. It is true that nothing can be achieved without using the elements of nature, but misuse and over utilization causes serious damage to the natural system.
The level of utilization of land depends on the socio-cultural and economic achievement of people living under different nature environment. Accordingly, people have developed different land use techniques and the land use pattern. Thus, land utilization is a dynamic process, varied spatially and temporally. Land use pattern has a long drawn effect on the economy as well as on the ecology of any area.
Wasteland Map of Assam (1:50000) : 2008-09
Land Use Pattern:
The land use classification scheme developed by the National Remote Sensing Agency (Dept. of Space, Govt. of India) has been adopted for the State of Assam. The Major classes of land use as identified by the Assam Remote Sensing Application Centre are built-up land, agricultural land, forest land, wasteland, water bodies and others.
Assam is basically an agriculture dependent state. More than 65 per cent of its total area is under agriculture. The increasing pressure of population and the lack of employment opportunity in other sectors, the pressure on agricultural sector is increasing alarmingly. This situation leads to the intensification of agricultural sector and the fragmentation of land holdings. Such situations cause serious damage to the land and the economy of the state.
Agricultural land:
Agriculture is the dominant land use category in the state. It account for about for about 54.11 per cent of the total geographical area of the state. Including persons dependent on plantation, more than 80 per cent of the total population of Assam is dependent on agriculture. With the increase of population and the development of agro-technology, lots of changes take place in the agricultural scenario of the state. The net area sown as well as the gross cropped area increased significantly in the last few decades. This decreases the area under other uses especially area under forest. Although, the development in agriculture has tremendous important in the economy of the state but the ecological impacts of the changing land use pattern need to be considered.
Forest land:
As per the land use data, the total area under different types of forest is only 17,26,387 ha. which is about 21.9 per cent of the total area of the state. The actual area under forest in the state is less than the area under it should be as per its location i. e. 33.3 per cent to the total area. Out of the total (21.9 %) forest area 12.47 per cent is under evergreen/semi evergreen forest, 5.7 per cent under deciduous forest, 2.72 per cent in degraded forest and 1.01 per cent is under forest plantation. The over exploitation of forests and the large-scale encroachment of forest lands, the forest resources of the state depleting very fast. The shifting cultivation especially in the hill districts is one of the principal causes of the forest lost in the state.
Wastelands:
Among the most potential sector of land uses for development is the wastelands. The total area under different types of wasteland in the state is 10606020ha. which account for about 13.5 per cent of the geographical area of Assam. The different types of wasteland seen in the districts are – water logged area, swamps and marshes, gullied and ravinous land, land with or with out scrub and the area under shifting cultivation. Shifting cultivation constituted the most dominant class accounting about 9.48 per cent state’s area. The two hill districts namely Karbi Anglong and the N.C.Hills have 42.37 per cent and 59.65 per cent areas respectively under shifting cultivation. The large-scale shifting cultivation is one of the main causes of forest degradation in the districts.
The swamps and the marshes of the state are ecologically very important as these areas having rich aquatic biodiversity. But due lack of proper conservation and development, most of them are now being filled up and converted to agricultural land. The over and uncontrolled exploitation of these swamps and marshes, the aquatic biodiversity of these areas have lost to greater extent. The degradation of forest in the upper catchments of the rivers intensive the problem of gully erosion, which already reach to unmanageable proportion in some area of the state.
Thus an integrated wasteland development strategy is the need of the time. The distribution of wastelands in different districts of the state are as in the table below:
Others:
Among the other categories of land use, the grassland/grazing land and mining area are seen in Assam. The grasslands claim 3.00 per cent of the total area of the state whereas the mining covers only 0.02 per cent of the total area. Mining area is mainly seen in the Tinsukia district of the state. The grasslands are widely distributed in the state
FOREST RESOURCES
FOREST RESOURCES
Assam is known for its extensive forest areas and availability of rich floras and faunas besides other valuable forest products. As per information available from the State Forest Department, the total area under forests in Assam was 26,781.91 Sq.km. at the end of March, 2003, out of which 15,492.329 Sq. Km. was under Reserved Forests and 2,860.942 Sq. Km. under Protected Forest Area. But this rich forest cover and valuable forest resources of the state are disappearing rapidly particularly from the last few decades due to massive deforestation, illegal felling, forest fragmentation, encroachment in the fringe areas, poaching, biopiracy and other unplanned development activities.
1) Terrestrial Ecosystems:
Forest Ecosystem: Forest ecosystem of the State includes the national parks, biosphere reserves, wildlife sanctuaries and reserve forests. These ecosystems of the state are very rich in plant and animal diversity. The forest ecosystems of the state posses within them wetlands having rich aquatic diversity.
Grassland Ecosystem:
The grassland ecosystem occurs in the alluvial plains abd riparian flats throughout the state and many of the areas are generally inundated every year during the monsoon period.
The Forests area constitute about 34.14 percent of the total geographical area of Assam. The forests in the plain districts are managed by the State Forest Department while the authorities for management of the forest in the two hill districts are their respective District Councils.
Social Forestry
The Social Forestry programme is an important programme being undertaken by the State Forest Department. The programme mainly aims at increasing area under Afforestation especially in Residential Area and otherwise Occupied Areas of the State. The achievement under Social Forestry scheme was 3871 hectares of area during 2001-2002 against the targeted area of 3835 hectares The number of seedlings planted under this scheme was 96.76 lakh during the year.
Soil Type:
The diversified geological conditions, topographical characteristics, climatic situations and vegetation types have favour the formation of different types of soil in the state. The soils of Assam can broadly be divided into four main groups, viz. alluvial soils, piedmont soils, hill soils and lateritic soils.
The alluvial soils are extensively distributed over the Brahmaputra and Barak plain and are very fertile. The alluvial soils can further be divided into two main sub types-young alluvial and old alluvial soils. The young alluvial soils is characterized by modern alluvium deposits. The colour of these soils is generally gray to molted gray. On the other hand, the old alluvial soils occurs in some patches of Kokrajgar, Barpeta, Nalbari, Kamrup, darrang, Sonitpur, Lakhimpuir and Dhemaji district. Generally, the old alluvial soils are very deep with fine loams to coarce loams in texture. The piedmont soils are confined to the northern narrow zone along the piedmont zone of the Himalayan foothills. The soils are very deep and fine to coarse loamy in texture. The hill soils are generally found in the southern hill regions of the state. These soils are deep, dark grayish brown in colour and fine to coarse loamy in texture. The lateritic soils are extensively occurring in N.C. Hills district and in some parts of the southern Karbi Plateau. These soils are dark and finely textured with heavy loams.
Soils
Soil is the most valuable nature resource and serves as one of the prime requisite of life. Soils and in its turn the land through their relative fertility support all agricultural activity ant the plant growth and thereby the most important element of the natural ecosystem. As regards the soils of Assam, geology (parent material), topography and climate seem to play vital role in their formations. Therefore, under varying geological conditions, topographical characteristics and agro-climatic situations different types of soils are found to occur in the hills, piedmonts, plateaus and plains. The soils of Assam may thus generally be divided into four groups, viz.
Alluvial soils
Piedmont soils
Hill soils
Lateritic soils.
a) Alluvial Soils:
The alluvial soils are extensively distributed over the Brahmaoutra and Barak plain. These soils are very fertileas they formed from the alluvium deposits, deposited by the rivers Brahmaputra, Barak and their tributaries. The alluvial soils of Assam can be further be divided into two sub-types base on some micro differences in character such as – younger alluvium and old alluvium.
The younger alluvial soil occurs in an extensive belt of the north-bank and south-bank plains including the active flood plains of the Brahmaputra and the Barak rivers. This soil characterized by recent deposition of alluvium, moderately deep to very deep with grey to molted grey colour . It is mostly composed of sandy to silty loams and slightly acidic in nature. On the riverbanks it is less acidic and sometimes nutral or slightly alkaline. The soil lack in prifile development and is deficient in phosphoric acid, nitrogen and humus.
The old alluvial soil occurs in some patches of Kokrajhar, Barpeta, Nalbari, Kamrup, Darrang, Sonitpur, Lakhimpur and dhemaji districts between the northern piedmont soil belt and the southern new alluvial soils of the Brahmaputra valley. In the south bank districts of the valley it occurs in a narrow belt bounded between the southern hill soils and northern new alluvial soils. In the Kopili plain covering Nagaon district the old alluvium finds wider extension. The Barak plain, on the other hand, has some elongated patches of old alluvial soil confined between the new alluvial soils of the active floodplain and the hill soils boardering Mizoram. Generally the old alluvial soil is very deep, brownish to yellowish brown with texture of fine loams to coarse loams and is slightly to moderately acidic.
b) Piedmont Soils:
The piedmont soils are confined to the northern narrow zone along the piedmont zone of the Himalayan foothills. These soils comprise the Bhabar soil and the Tarai soil, covering respectively the Bhabar and the Tarai belt of the Brahmaputra valley. The Bhabar soil occurs in the narrow belt along the Assam-Arunachal boarder extending east up to the river Subansiri’ is characterized by unassorted detritus of boulders, pebbles, cobbles, sand and silts. This soil is deep and fine to clay loamy in texture. The Tarai soil occurring just south of the Bhabar soil extends up to Dihang river in some discontinuous narrow patches.This soil varies from sandy to silty loams that remain saturated and support tall grasses in a series of swamps.
c) Hill Soils:
The hill soils are generally found in the southern hilly terrains of the state. The fertility of these soils defers greatly in different regions. These soils are rich in nitrogen and organic matters. On the basis of the physical texture and chemical composition, the hill soils may be divided into –red sandy soils and red loamy soils. The red sandy soils are distributed covering as narrow belt along the Assam- Meghalaya border, the Karbi Plateau, southern part of Barail range of the N.C.Hill district and some parts of the foothills along the eastern border of the Cachar district. This soil is very deep and well drained, brownish to yellowish in colour, strongly to moderately acidic with high organic content. The red loamy soils, on the other hand, occurs in the narrow southern foothill belt running along the Assam’s boarder with Arunachal and Nagaland and also in the southern fringes of the Karbi Plateau and the Barail hills of N.C.Hills district. These soils are very deep, dark grayish brown to yellowish red and fine to coarse loamy. Red loamy soils are slightly to moderately acidic and these lack in nitrogen, phosphoric acid, humus and lime.
d) Lateritic Soils:
The lateritic soils in the state extensively occurs almost entirely over the N.C.Hills district covering some parts of southern Karbi Plateau while few patches are confined to eastern margin of the Hamren sub-division of Karbe Anglong district, southern boarder of Golaghat district and the northern part of the Barak plain along the foothills of the Barail range. These soils are dark and finely texture with heavy loams and deficient in nitrogen, potash, phosphoric acid and lime.
The soils of Assam are very rich in content of nitrogen and organic matter. The alluvial soils of the Brahmaputra and the Barak valley are highly fertile and are very much suitable for raising of varieties of crops round the year such as cereals, pulses, oilseeds, plantation crops etc. The well drained, deep, acidic alluvial soils of upper Assam with good proportion of phosphoric content are mostly for the plantation. New alluvial soils occurring in the charlands of the Brahmaputra are most suitable for growing oilseeds, pulses and rabi crops. The alluvium of the plains offers excellent opportunity for cultivating rice and vegetable. The soils occurring in the upper reaches of the hill slopes are very suitable for horticulture and plantation crops.
Soil Erosion:
Riverbank erosion during high flood period in the valley is a regular annual feature. Over bank flood due to breaches in the embankment render the fertile cultivable land unsuitable for crop production due to deposition of coarse sand on the surface to a variable depth. As per Assam Government Revenue Dept. records, an area of 6116 hectares of land was affected by soil erosion in Upper Brahmaputra Valley and North Bank Plain zone during 1994.
The highly productive and fertile soils of Assam are now facing the serious problem of soil erosion like other parts of the country. Under heavy precipitation and humid climate loss of topsoil through surface run-off is the most common type of soil erosion in the entire state. The problem of topsoil erosion is severe in the plain during the flood season. It is estimated that nearly 3.2 million hectares of land of the plain districts of the state are vulnerable to topsoil erosion with varying intensity. Terrain deformation through mass movement is another type of soil degradation, which is primarily confined to the hill districts of Karbi Anglong and N.C. Hills covering an area of about 1.53 million hectares. Another important type of soil erosion in the state, which assumed serious proportion in the recent time, is the bank erosion by the rivers. It is observed that at some places, a few kilometers of bank along the villages, fertile agricultural lands and roads are being eroded by the rivers. Majuli, the largest river island of the world is now seriously affected by the erosion and virtually facing the threat to existence. The extent of loss to the bank erosion varies from year to year depending on the severity of floods in the state.
Land Pollution:
Land is laid waste by destructive means of plantation and polluted by the disposal of domestic and industrial waste. Jhum cultivation, new habitations and settlements, big reservoirs and dams made for various uses such as irrigation, water supply and power, etc. play a role is destroying and adversely changing the land surface. Unscientific mining and extraction of raw materials from the ground have lasting damage on land. Sludge from the sewage plant is deposited on the land surface and which affect the fertility of the soil. They are harmful to human beings and the plant kingdom alike.
Soil Erosion Statistics of Assam
Social Forestry Parks Constructed
Estimated area affected by soil erosion in Assam under special problem
Sources:
bhuvan.nrsc.gov.in
NEDFi Data Bank
Department of Environment & Forests, Government of Assam
http://online.assam.gov.in/
Need More Information, Click ISBEID