摘要
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高耕作>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、人工掏挖与等高耕作方式下地表高程平均分别降低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<等高耕作。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)产沙量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。
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,and also despression storage went down except CK.The runoff yield of contour tillage,artifical hoe,artifical dig decreased by 38.17%,17.88%,9.43% compared to CK,respectively,and the amount of sediment yields were 65.6%,36.3%,23.4%.The descending order of the changes of runoff time is contour tillage,artifical hoe,artifical dig,and CK,there was a sharp increase of runoff yield at the beginning of rainfall,and then has a smooth upward trendency;the initial sediment yield increased,then decreased and gradually developed to a stable process.The impact of slope on runoff and sediment showed that the greater the slope degree the earlier of runoff generation and the more the runoff and sediment yield.In conclusion,the effects of soil and water conservation of tillage practice are related obviously with soil surface micro-relief.
出处
《中国水土保持科学》
CSCD
2011年第2期64-70,共7页
Science of Soil and Water Conservation
基金
国家自然科学基金"水蚀过程中地表糙度的演化及其侵蚀响应规律研究"(40871133)
国家973计划"不同类型区土壤侵蚀过程与机理"(2007CB407201)
黄土高原土壤侵蚀与旱地农业国家重点实验室基金"黄土坡面土壤侵蚀形态演化数值模拟"(10501-283)
关键词
耕作措施
人工降雨
地表糙度
黄土
tillage practices
simulated rainfall
soil surface roughness
Loess
