Studying On Soil Wind Erosion And Potential Duststorm Source Of Duststorm Area In Northwest China

Object: study the characteristic of the soil wind erosion of northwest China,make clear the potential dust source of northwest China,provide the theoretical support for the duststrom administration measures.Methods:Used on-the-spot tests,experiments and soil wind erosion test of different scale during the duststrom in HOTAN and WUWEI,MINQIN of GANSU provice,combined with the history material and RS image treatment,analysed the characteristic and reason of the duststorm in northwest China,studyed the soil wind erosion characteristic and the potential dust source of dust area in northwest China.Results:The annual happen times of the northwest dust area presents slowly descend tendency,but the situation of the duststorm defence is still critical. The natural and man-made element result in the frequent dust weather.In the HOTAN test, the quantity of sand transport and desendent of the desert,the intermediate zone and oasis had significant differences and had an obvious relationship with vegetation coverage. Under the small scale test,The quantity of sand transport of the different earth'surface had significant differences,the quantity of sand transport of the farm land with 82% average vegetation coverage was less than 10% of the desert sand transport quantity,In the windward and leeward test,the leeward sand transport quantity increased 2.39% than the windward'in farm land,7.90% in abandoned farm land and reduced 2.24% in farm land,the test results indicated the importance of increasing vegetation coverage to alleviate soil wind erosion in hotan. In WUWEI,MINQIN test, the oasis tillage area has the highest percentage of pellet which is easy to rise, the Gobi,bush,degenerate grasslands have the most potential duststorm source.The duststorm source in west,northwest part of this area provided material factor for 2005·7·17 duststorm.. Increasing the vegetation coverage of the area above can alleviate the duststorm endanger.Conclusions:High coverage vegetation can enhance the soil's ability to denfence the wind erosion obviously,of the area above can alleviate the duststorm endanger,increase the vegetation coverage is the effective channel to reduce the soil wind erosion.The percentage of the soil easily to be eroded by wind in farmland and farmland abandoned is higher than desert and Gobi.The potential dust source quantity of the Gobi,bush and degenerate grasslands are more than farmland and desert.Sealing and breadingthe Gobi,bush and degenerate grasslands,establishing the forest system for defencing wind and strengthening the sand, expanding the crops like winter wheat,lucerne which has high vegetation coverage during the frequently-occurring time of the dust weather,resuming the farmland abandoned,expending the conservation tillage technologies like no-tillage,minimum-tillage,reserving high stubble and straw coverage can reduce the duststrom endanger in northwest China.