金沙江流域水土流失现状与河道泥沙分析

SURFACE EROSION AND FLUVIAL SILT IN THE JINSHA RIVER WATERSHED

对金沙江流域水土流失、河道泥沙及主要影响因素系统作了分析，认为地质、地貌及气候因子是影响水土流失的主要因素，人为活动加剧水土流失的发生发展。河道泥沙主要来自金沙江下游，特别是下游干流河谷区间，流域的地面侵蚀与河道泥沙的空间关系不密切，影响输沙量的主要因素为年径流量和清水区年径流量，以及滑坡、泥石流等重力侵蚀，尽管水土流失治理对于流域的河道泥沙减沙效应显著，但短期内对流域干支流输沙量影响甚微。

Based on the analysis of major influence elements of the surface erosion and fluvial silt in the Jinsha River Watershed,the authors confirm that the conditions of geology, landform and climate are the major factors effceting the surface erosion,and the injudicious social economic activities intensified the occurrence and development of soil and water loss.The fluvial silt is chiefly produced in the lower reaches of the River,especially in the main river valley of the lower reaches.The surface erosion of the watershed is not closely related to the flvial silt in space,the major elements which in fluence the amount of water borne silt are the runoff volume in the watershed and in the clear water are of the watershed.Although the effect of the control of soil and water loss is remarkable in the reduction of fluvial silt in small warershed,yet is scarcely in fluences the amount of water borne silt in the mainstream and tributaries of the River.The fluvial silt of Jinsha River Watershed will not be notably reduced in short times.