Land Resources it consists of Land as a resource, Land Degradation, Man induced Landslides, Soil Erosion and Desertification.
Land as a Resource :
Land is the Solid earth where most of the animals and plants are living. About 33% of the earth's surface is made up of land, endowed with variegated soils, minerals and rocks. Some land is unstable and unsuitable for certain kinds of structures and activities. Centuries ago, when the population was much less, there was sample space for all, hence land use planning mattered less. But now a days, with the growing population, it becomes increasingly important to consider not only what can safely be done with a given piece of land, but also, what are the optimum uses to which it can be put.
In fact in the densely populated areas, piece of land is used for several purposes. The strategies involved are termed "Multiple Use" and "Sequential Use". Multiple Use, as the name implies, means using the same land for two or more different purposes one after another. By and large the decisions ultimately made are influenced by biological, eclogical, economical, political and aesthetic factors. Thus, elsewhere, the lands are used for agriculture, dwelling, industrial activities, recreation and also as military bases, scientific laboratories and playgrounds. It is also a great scenic resource and important Wild life habitat.
Land Degradation :
Consequences are manifold when the land gets susceptible to pollution, erosion and other disruptions. Land degredation may be natural or man-induced. The natural land degredation is generally due to any one of the following causes.
They are:-
1. Differential Erosion in Heterogeneous Lithology.
2. Excessive rainfall and later floods.
3. Sudden Earthquakes and Tremors.
4. Deposition of ashes from a near by Volcano.
5. Forest Fire and associated combustion.
6. Mass Movements
7. Sea level changes.
8. Desertification by of wind-blown sand deposits.
The man induced land degredation is generally due to any one of the following causes.
They are:-
1. Mining of Minerals, Sand and Water.
2. Stagnation and dumping of industrial effluents, domestic sewages and wastes.
3. Military operations and bomb testing activities.
4. Over Exploitation of agricultural lands and excessive use of fertilizers, pesticides and insceticides.
5. Idially kept unused lands.
Man Induced Land Slides :
Landslides are rapid down hill movements of masses of rocks or weathered erosional debris, soil, and amy any thing else that be in the way, such as houses, fences and roads. The preconditions for landslides are slopes too steep for the frictional forces to hold the heterogeneous mixtures of rock, soil and unconsolidated sediment in place against the force of gravity. The landslide amy be triggered by natural forces or by human activities. Deforestation, toe removal during cutting of highways and railways around hills, damming of water along hill slopes, anomalous fordable aroung unstable regions and construction of buildings on hill slopes are few causes for man - induced land slide.
Soil Erosion :
The product of weathering called Soil is very important for the develpoment of the livestock. It contains mainly minerals and organic matters. The geological agents like wind and river water are continually removing the soil from its place of origin, by a process called Erosion. Such kind of erosion is harmful for the eco-environmental system and is called Soil Erosion.
Hazards of Soil Erosion :
Soil Erosion usually affects the agricultural production. In fact, the running water and moving wind are removing potential organic matter and nutritious soil from the top layer. As a reslut, the fertility of the soil is completely lost and effective cultivation become impossible. The second kind of loss produced by soil erosion is change in land structure. When Soil Erosion is intensified, small gullies are formed on the surface of the land and hence, the land appears with full of scares. Thirdly, the eroded soil particles are concentrated in the running water amking it turbid and
polluted. Sediments accumulated in dams and reservoirs may reduce the life period of such constructions. Sometimes these fine deposits silted
along the coast may stop the navigation.
Man Induced Soil Erosion :
Soil is eroded when the slope conditions of land gets changed. However, amn induced soil erosion may be due to cutting of wood from the forest for industrial and domestic purposes. Mining and associated blasting operations may cause severe loss to soil of the respective area. Wrong method of plough-practices along the hill slopes may promote soil erosion. Over grazing and removal of grass cover increase soil erosion. The off -road- vehicles will trigger the soil erosion along the highway sides. Slope modifications initiated by construction of new buildings along hill slopes, cutting of roads and rails may alos disturb the stability of slopes. Such change in the repose angles may induce soil erosion.
Preventive Measures of Soil Erosion :
Soil is one of the nature's bounties in which most of teh lives are dwelling and plants are rooted. This valuable gift of nature is not polluted by man, by his over agricultural explotiation, but also lost by his improper urbanization. hence, prevention of soil erosion from human activities is inevitable. Controlling the flowing conditions of streams may mitigate soil erosion. Construction of proper check-dams and canals may help in arresting soil erosion. Proper plough practices along hill slopes, afforestation, and growing bushes across the hill slopes may combat soil erosion.
Desertification :
Almost one third of the earth's land area is arid or semi arid. Deserts are present in all parts of the world. We have hot deserts around equator and cold deserts around poles. SInce the human activity is more around the hot deserts, we will list the reasons for man induced desertification in hot climates.
They are:-
1. Excessive population and subsquent deforestation fro dwelling.
2. Over exploitation of ground water.
This article is very useful to everyone to know about the Land Resources.