黄土高原风蚀水蚀交错区侵蚀产沙过程及机理  

Sediment-yielding process and its mechanisms of slope erosion in wind-water erosion crisscross region of Loess Plateau,Northwest China

作　　者：脱登峰[1,2] 许明祥[2,3] 郑世清[3] 李强[3] 

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100 [2]西北农林科技大学水土保持研究所,陕西杨凌712100 [3]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《应用生态学报》2012年第12期3281-3287,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41171422;40971174);中国科学院战略性先导专项(XDA05050504);中国科学院"西部之光"人才培养计划项目资助

摘　　要：黄土高原风蚀水蚀交错区由于风蚀、水蚀的耦合作用,侵蚀程度剧烈、过程复杂.采用风洞与模拟降雨相结合的方法,研究了风水交错侵蚀条件下坡面产沙变化过程及侵蚀作用机理,定量分析了风蚀对水蚀的影响程度及其与水蚀的关系.结果表明:风蚀与水蚀之间存在明显的正交互效应.风蚀促进了侵蚀形态的发展,改变了降雨产沙随雨强变化的量化关系.雨强60、80mm·h-1时,未风蚀处理下,坡面产沙量随降雨历时呈下降趋势,并趋于稳定;但风蚀处理后,产沙量降低至一定谷值时,又呈波动增加趋势.60、80、100mm·h-1雨强下,风蚀处理的坡面产沙量增幅为7.3%～27.9%(风速11m·s-1)、23.2%～39.0%(风速14m·s-1);雨强120、150mm·h-1时,降雨15min内,各处理的坡面产沙量均呈下降趋势,但随着降雨历时的延长,风蚀处理的坡面产沙量较未风蚀处理呈先低后高的变化趋势.风水交错侵蚀作用机理复杂,在时空分布特征、能量供给、侵蚀力作用方式等方面相互联系、互相促进.Due to the coupling effects of wind and water erosions in the wind-water erosion crisscross region of Loess Plateau, the slope erosion in the region was quite serious, and the erosion process was quite complicated. By using wind tunnel combined with simulated rainfall, this paper studied the sediment-yielding process and its mechanisms of slope erosion under the effects of windwater alternate erosion, and quantitatively analyzed the efffects of wind erosion on water erosion and the relationships between wind and water erosions. There was an obvious positive interaction between wind and water erosions. Wind erosion promoted the development of microtopography, and altered the quantitative relationship between the sediment-yielding under water erosion and the variation of rainfall intensity. At the rainfall intensity of 60 and 80 mm· h^-1 , the sediment-yielding without wind erosion decreased with the duration of rainfall and tended to be stable, but the sediment-yielding with wind erosion decreased to a certain valley value first, and then showed an increasing trend. At the rainfall intensity of 60, 80, and 100 mm · h^-1 , the sediment-yielding with the wind erosion at speeds of 11 and 14 m·s^-1 increased by 7.3% -27.9% and 23.2% -39.0% , respectively, as compared with the sediment-yielding without wind erosion. At the rainfall intensity of 120 and 150 mm · h^-1 and in the rainfall duration of 15 minutes, the sediment-yielding with and without wind erosion presented a decreasing trend, but, with the increase of rainfall duration, thesediment-yielding with wind erosion showed a trend of decreasing first and increasing then, as compared with the sediment-yielding without wind erosion. The mechanisms of wind-water alternate erosion were complicated, reflecting in the mutual relation and mutual promotion of wind erosion and water erosion in the aspects of temporal-spatial distribution, energy supply, and action mode of erosion forces.

关 键 词：风水交错侵蚀 产沙过程 侵蚀机理 模拟试验 

分 类 号：S157.1[农业科学—土壤学]