The Causes of Land Degradation
Land is degraded when the biophysical environment is compromised. Any disturbance or change that is undesirable or causes damage to land degrades it. Naturally occurring phenomena such as the recent earthquakes and tsunami in Japan, do not cause land degradation. The overall effect of land degradation is the reduced productivity of land. Reduced productivity goes along way into affecting the food basket of a country. This means that the wealth and economic stability of a nation will be greatly reduced.
Clearing land for the purposes of agricultural land, wood for fuel, timber for construction of houses and furniture causes land degradation. Clearing of vegetation and forests degrades land because it leaves the land bare and exposed to wind and water. This two elements cause massive erosion as they wash away the top layers of the soil that is rich and organic, and can support agriculture.
Intense farming and other poor farming practices also causes depletion of soil nutrients. This is because the chemical fertilizers applied to accelerate production of crops kills the naturally occurring soil nutrients. Poor irrigation practices like irrigating with water that contains sodium bicarbonate leads to soil alkanisation, which leads to poor soil structure.
Quarrying of sand, stone, minerals and ore also disturbs the land or changes the landscape of a given environment. The presence of a quarry near a residential area poses danger to the people living around it. This is because it can be breeding grounds for diseases vectors like mosquitoes. Water-filled quarries are also dangerous swimming places and there are statistics everywhere of people drowning in quarries.
Rural to urban migration has led to the emergence of urban sprawls. This is because there is high demand for places to live for the hundreds and hundreds of poor city dwellers. As a result many cities have seen the mushrooming of slums with close to no sanitation facilities, non-existent waste management mechanisms. All these lead to land degradation.
Overpopulation also indirectly causes land degradation; this is because there is increased demand for land for agricultural use. This also results in good agricultural land being saturated and over-farmed hence leading to soil infertility. With population increase and the demand for food comes the need for more water, for a place that experiences less than adequate rainfall, this demand leads to over-drafting; a process that affects the quantity of ground water. In over-drafting, the rate of underground water harvesting exceeds the rate at which nature replenishes the aquifers.