【作者】 刘国庆；

【导师】 李少昆；

【作者基本信息】 石河子大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 目的:研究西北沙尘多发地区沙尘暴土壤风蚀特征,明确西北地区潜在尘源,为西北地区沙尘暴危害的治理提供理论支持。方法:通过在新疆和田、甘肃武威民勤的实地考察取样、不同尺度条件下沙尘暴发生期间土壤风蚀试验,结合历史资料及遥感影像分析,分析了西北地区沙尘天气发生特征及原因,研究了西北沙尘多发区土壤风蚀特征及潜在尘源。结果:建国以来西北沙尘区沙尘年发生次数总体上呈缓慢下降趋势,但防御沙尘天气的形势依然严峻。西北地区沙尘天气的频繁发生是由自然、人为原因共同作用的结果。在和田试验中,主要地表类型沙漠、过渡带和绿洲土壤输沙量、降尘量具有显著性差异,并与覆盖度存在明显的相关性。在小尺度下观测的结果表明,不同地表类型输沙量也存在显著差异,相同高度下平均覆盖度82%的农田输沙量不足沙漠输沙量的10%,沙漠观测点下风口输沙量比上风口增长2.39%,弃耕地下风口输沙量比上风口增长7.90%,而覆盖农田下风口输沙量比上风口减少2.24%,说明提高植被覆盖对减少当地土壤风蚀的重要性。在武威民勤试验中,绿洲耕作区易起尘颗粒百分含量最高,戈壁、灌丛、退化草原潜在尘源总量最大,农田、沙漠次之。该地区西部、西北部的沙尘源为7月17日沙尘暴提供了物质条件。增加上述地区的植被覆盖度可减轻当地沙尘暴危害。结论:西北绿洲区农田、弃耕地土壤中易起尘物质百分含量高于沙漠、戈壁。河西走廊东部戈壁、灌丛、退化草原含有的潜在尘源总量最大,农田、沙漠次之。高覆盖度植被可明显提高土壤抗风蚀能力,提高植被覆盖度是减少西北沙尘多发区土壤风蚀的有效途径。对戈壁、灌丛、退化草原进行封育,营造防风固沙林体系,在农田中推广种植冬小麦、苜蓿等在沙尘暴多发时期植被覆盖度高的作物,恢复弃耕地、推广少耕免耕、留高茬及秸秆覆盖等保护性耕作技术可减轻西北地区沙尘暴危害程度。更多还原

【Abstract】 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.更多还原