黄土坡耕地耕作方式不同时微地形分布特征及水土保持效应

 利用GIS技术模拟黄土坡耕地微地形空间分布特征，并对其水土保持效应进行研究。结果表明：1)地表微地形起伏大小依次为等髙耕作 > 人工掏挖 >人工锄耕 > 直线坡面（CK),和CK相比，人工锄耕与人工掏挖微地形呈随机相间的坑洼特征，等高耕作呈沟垄相间的空间特征；雨后CK、人工锄耕、人工掏挖与等商耕作方式下地表髙程平均分别降低0.015、0.014、0.018和0.015 m。2)除CK地表填洼量为增大外，其余方式均为减小；地表产流时间依次为直线坡面 < 人工掏挖< 人工锄耕< 等髙耕作。3)产流量随降雨时间呈先增大,后趋于平稳的过程。4)与CK相比，等高耕作、人工锄耕和人工掏挖产流量分别减小38. 17%、17.88%和9.43%。5)产沙最随降雨时间呈先增大，后减小并逐渐趋于稳定的过程，与CK相比，等高耕作、人工锄耕和人工掏挖产沙量分别减小65.6%、36.3%和23.4%。6)坡度对产流产沙的影响主要是坡度越大,产流时间越早，产流产沙量也越大。因此，不同耕作方式的水土保持效应与其形成的地表微地形空间特征密切相关。

Micro-relief characteristics of loess sloping farmland under different tillage practices and its effects of soil and water conservation

The spatial distribution of micro-topographical features of loess sloping farmland and its effects of soil and water conservation were studied using GIS under simulated rainfall conditions.The results showed that the descending order of the changes of micro-relief is contour tillage,artifical dig,artifical hoe,and CK,and the mean changes of different type of tillages(CK,artifical hoe,artifical dig and contour tillage) decreased as 0.015,0.014,0.018 and 0.015m after simulated rainfall conditions,respectively...