基于淤地坝淤积信息的小流域泥沙来源及产沙强度研究

根据黄土丘陵区王茂沟流域关地沟3号淤地坝29年泥沙沉积旋回变化,以及各旋回层泥沙中、坝控流域沟间地和沟谷地表层土壤中137Cs的测量,结合淤地坝修建、运行历史资料及次降雨资料,估算了坝控流域沟间地和沟谷地的相对产沙量和坝控流域不同时期的侵蚀产沙强度。研究表明,沟间地是该小流域泥沙主要来源,该流域泥沙的70%源自沟间地;坝控流域1959~1987年期间,年侵蚀产沙强度由强变弱,呈显著降低趋势。

Research on the Sediment Source and Sediment Yield Intensity in a Small Watershed Based on the Alluvium Information of Soil-Saving Dam

The relative sediment production in the inter-gully land and gully land controlled by soil-saving dam and the sediment yielding intensity by erosion in the different periods in the soil-saving dam controlled watersheds are estimated based on the measurement of 137Cs in the sedimentary deposit rotary change and the sediments of each rotational layer for 29 years by No.3 soil-saving dam in Guandi gully of Wangmaogou watershed in the Loess Hilly Area and in the surface soil layer of inter-gully land and gully land controlled by soil-saving dams as well as in combination with the analysis of history of soil-saving dam construction,operation data and rainfall data records.The studies indicate that the inter-gully land is the main source of sediments in the small watershed,in which 70% of sediments come from,and that in the soil-saving dam controlling watershed,the sediment yielding intensity by yearly soil erosion during the years of 1959-1987 become from strong to weak,appearing to have the significantly decreasing trend.