water and soil loss
Soil and water loss (also known as erosion and soil erosion) is a kind of natural phenomenon, it is to point to the earth's surface is constantly by wind, water, ice melt, etc of force, wear and surface soil and parent material, rock by all kinds of damage and mobile, accumulation process and water itself loss phenomenon, including soil erosion and water loss.
Special "soil and water loss" is referring to water erosion surface soil phenomenon, make water and soil resources and land productivity damage and loss, the influence to the survival of humans and other animals and plants. Human land use, especially for water and soil resources not reasonable development and management, make the soil cover destruction, bare soil by hydraulic erosion, loss is greater than the parent material into the amount of soil fertility, soil erosion by surface soil erosion, loss of subsoil to parent material loss, and finally exposed rock.
Cause the cause of soil and water loss
Soil and water loss may be due to the natural environment of the cause, such as topography, a steep a large amount of precipitation, or geological changes. But more is due to human activities lead to, such as overgrazing, land reclamation, deforestation, mining road, Fried mountain quarrying, etc. Loss by water erosion may move or the wind, ice and happen. Soil and water loss is unfavorable natural conditions and the unreasonable activities of human being from the mutual mixed effect. Soil and water loss on the local and rivers downstream ecological environment, production and life and economic development cause great harm. Soil and water loss damage surface integrity, and reduce the soil fertility, cause land hard petrochemical, desertification, affect agricultural production, safety, increased threat town drought, the occurrence of natural disasters, development, leading to people living in poverty, production conditions worsen, hinder economic and social sustainable development.
Soil and water loss is in wet or semi-humid region, due to serious damage to
vegetation. If it is in the arid region of vegetation destruction, can lead to dust storms or land desertification, and different from the soil and water loss.
Because vegetation destroyed, plus rain and surface water erosion, lead to soil and water loss.
Increasing vegetation coverage, the soil and water conservation, also can prevent the occurrence of soil and water loss.
harm
Erosion is the natural environmental deterioration of the important reasons. Because of the water flow, take on the surface of the earth, which makes the land became infertile soil, rock bare, vegetation destruction, ecological deterioration. This natural phenomenon can be cycle effect, ecological deterioration caused by soil erosion, soil and water loss and makes the ecological worse. So the land degradation, not farming. Plant death, surface bare. Bad ecological and more lead to climate change, making biological survivable environment deteriorate.
Soil and water loss also makes sediment deposition, river plate drive up, cause water impeded, the water quality is cloudy and even lead to flooding, river diversion, as China's Yellow River.
China's water loss and soil erosion intensity is divided into: Mired, mild, moderate, strength, very strength, severe and six.
From erosion type look, northwest loess plateau soil erosion is mainly because of the soil loose, rainfall concentrated. Loess or loose weathering crust in the absence of vegetation protection case vulnerable to erosion. The slope is steep, surface runoff velocity faster, soil erosion on erosion force is stronger. The longer the slope surface from surface runoff, erosion force more and more strong. Mainly is the erosion type erosion; And the south area, relief, precipitation, rainfall intensity than soil water infiltration strength produce surface (super permeability) flow, which leads to the surface erosion erosion. Soil and water loss is usually is precipitation type erosion.
