1.The concept of soil erosion
In this process, the soil particles are loosened or washed away in the valleys, oceans, rivers, streams or far away lands. This has been worsening due to human activities such as agriculture and deforestation. Soil erosion is a continuous process that occurs either slowly or at an alarming rate. It results in a continuous loss of topsoil, ecological degradation, soil collapse, etc.
2.The causes of soil erosion
*Natural factors:
(1) Precipitation: rainfall concentration, uneven seasonal distribution; Heavy rain
(2) Soil: loose soil
(3) Vegetation: low vegetation coverage, poor soil and water conservation ability
(4) Topography: large relief, strong erosion by running water.
*Human factors:
(1) Vegetation destruction, deforestation, deforestation; Overcultivation, overgrazing, and excessive woodcutting destroy vegetation
(2) Unreasonable farming and irrigation systems
(3) Open-pit mining and road construction lead to vegetation destruction
(4) population growth is too fast and environmental awareness is poor
3.Jeopardize
(1) Damage soil fertility, resulting in agricultural production
(2) The development of gullies is aggravated, threatening the safety of industrial and mining transportation facilities
(3) The vegetation coverage is reduced, and the ecological environment is deteriorated
(4) silting rivers, lakes and reservoirs, raising river beds, aggravating flood disasters
(5) affecting the comprehensive development and effective utilization of land and water resources
An example:Loess Plateau
Causes of soil erosion in the Loess Plateau:
Nature factors
1. Low vegetation coverage and poor soil and water conservation
2. Rugged terrain and large slope, easy to produce soil erosion Natural causes
3. Frequent geological disasters - accelerate soil erosion
4. Precipitation is concentrated in summer, and heavy rain - easy to cause soil erosion
5. Loess has a special texture - it is vulnerable to erosion
6. Transitional geographical location - fragile ecological environment
Human factors
1. History built palaces, felled trees and fought wars Human causes
2. Population increase - agricultural reclamation
3. Unreasonable land use - round wastage, mining
Damage:
*On the surface, soil and water loss appears as soil erosion, but the process of soil and water loss is a unified change process of geomorphology, soil, biology and hydrology.
1. Sedimentation hazards: hydrological changes - sedimentation, flooding
2. Erosion hazards: geomorphic changes; Soil erosion in gully and gully; Topsoil loss and fertility decline
3. Ecological deterioration: vegetation reduction and gradual disappearance; Climate deterioration; Increased evaporation and drought.
*The hazards caused by soil and water loss interact with each other. For example, geomorphic changes will affect hydrological changes, and geomorphic changes will be affected by soil erosion. Soil erosion will also degrade vegetation, which in turn leads to climate deterioration.