|
|
|
| Current status and comprehensive control strategies of soil erosion for wind-water complex erosion region in the Northern agro-pasture zigzag zone of China |
| Wang Tao,Qu Jianjun,Yao Zhengyi,Zhang Weimin,Tuo Wanquan,Zhang Jingguang,Yang Gensheng,Chen Guangting |
| Cold and Arid Regions Environmental and Engineering Research Institute,CAS,730000,Lanzhou,China |
|
|
|
|
Abstract As a part of Northern agro-pasture zigzag zone,wind-water complex erosion region located mainly in south edge on Inner Mongolia plateau and the area along the line of Great Wall,the boundaries of east and south part is the south-east end of land desertification,and that of west and north is north-west end of dry farmland.It involves 6 provinces and 74 counties that total area is 42.77×10 4 km2 and total population is 2.4×10 7(in 2004) and average density of population per km2 is 57.There are some ecological problems in this region including desertification developing continuously and dust frequently,bearing capacity of land resources decreasing sharply,and eco-environment worsening obviously and natural calamity appearing frequently.The characteristic of soil erosion is that the action of wind erosion and water erosion alternates in temporal and overlaps in spatial.The wind-water complex erosion region can be divided into three sub region according the characteristics of soil erosion and ratio between two erosional agents: 1) wind-water well-matched region;2) wind erosion predominating region;3) water erosion predominating region.Being controlled by erosional agent systems and environmental systems,the erosion types in wind-water complex erosion region have clear spatial-temporal variation features.The wind erosion part is mainly in three sandy lands-Mowusu,Hunshandake,and Kerqin,The water erosion part is mainly in neighboring area of Shanxi-Shaanxi-Inner Mongolia and north the foot of Yanshan Mountain.The area of soil erosion in 2000 is 261 517.35 km2 which accounts for 61.14% of total land area.The amount of soil loss is 11.97×10 8 t,among which 5.55×10 8 t is eroded by water and 6.42×10 8 t is eroded by wind.In the past 20 years,the area of soil erosion in most parts of the region is decreased for great scale projects of soil and water conservation,but the area of soil erosion in some parts is still increasing.With enhancing eco-environment construction extent,by estimating,in future decades,the soil erosion situation will tend to reversion gradually;but the condition of soil erosion in part area will be still very serious.The comprehensive combating countermeasures in wind-water complex erosion region include carrying out the policy of putting prevention first and giving priority to protection;comprehensive combating by combining biological-agriculture technology with engineering;combining state ecological demand with farmer's economic needs;harmonizing economic development with environment protection in accordance with law;emphasizing technology research and improvement of technology content.On the basis of present situation of soil erosion in wind-water complex erosion region,two key projects bring forward in this paper which includes: 1) comprehensive control of coarse sediment area of Yellow River Basin;2) ecological restoration and regeneration.With putting in practice,the coarse sediment transported into Yellow River will be greatly reduced and soil erosion condition will be improved in the wind-water complex erosion region.
|
|
Received: 23 November 2007
|
|
|
|
|
null
|
|
null
|
|
|
|
