基于3S和^(137)Cs技术的三峡库区小流域泥沙输移比研究  

Sediment Delivery Ratio of Small Watershed in the Three Gorges Reservoir Region Based on 3S and Cesium-137 Tracing Techniques

作　　者：张一澜 文安邦[1] 俱战省[1,2] 严冬春[1] 史忠林[1] 

机构地区：[1]中国科学院成都山地灾害与环境研究所山地环境演变与调控重点实验室,成都610041 [2]中国科学院大学,北京100049

出　　处：《水土保持学报》2014年第3期46-51,共6页Journal of Soil and Water Conservation

基　　金：国家科技支撑计划项目(2011BAD31B03);中国科学院西部行动计划项目(KZCX2-XB3-09);国家自然科学基金项目(41201275)

摘　　要：用3S技术对重庆忠县石宝寨的菱角塘小流域进行侵蚀单元的划分,通过137 Cs示踪技术配合GIS空间插值法,评估小流域1963年以来的地面侵蚀量;同时,以137 Cs定年法为主要研究手段,确定塘库不同层位的淤积泥沙的年龄,计算1963年以来小流域塘库泥沙淤积量,从而获得小流域以塘库入口为观测断面的泥沙输移比。研究结果表明:(1)不同土地利用类型的土壤侵蚀量差异明显,从1963-2013年这50年间,小流域侵蚀总量为7 240.5t,林地侵蚀总量为2 095t,坡耕地土壤侵蚀总量为5 145.5t,是林地侵蚀总量的2.45倍;(2)用137 Cs定年法进行计算得出小流域塘库淤积总量为1 927.5t,输出库外的泥沙643t;(3)计算菱角塘小流域1963年以来的泥沙输移比为0.36,小流域的低泥沙输移比说明流域内在坡面下方集中分布的水田以及修建的塘库能够很好拦蓄流域上部坡面的侵蚀产沙。Soil erosion and sediment delivery ratio was conducted on the Lingjiaotang small watershed of Shibao town in Zhongxian county, Chongqing, using 3S and cesium-137 tracing techniques. The results showed as following： （1）Soil erosion amount in different land use types varied greatly, soil erosion amounts for the small watershed, forestland and sloping cultivated land were 7 240.5 t, 2 095 t and 5 145.5 t, respectively, which soil erosion amount for sloping cultivated land was 2.45 times greater than that for forestland. （2）The pond deposits amount dating with 137Cs in the Lingjiaotang small watershed was 1 927.5 t and the sediment amount transported out of pond was 643 t. （3） The calculation of sediment delivery ratio in the small watershed was 0.36. It indicated that the paddy fields and pond loeated in the lower watershed had a great importance for decreasing sediment yields and played an important role in soil and water conservation in the Three Gorges Reservoir region.

关 键 词：3S技术 137 Cs示踪技术 三峡库区 泥沙输移比 

分 类 号：S157.1[农业科学—土壤学]