黄丘一区地理概况及小流域土壤侵蚀特征  

Geography in the First Subzone of Gullied Rolling Loess Region and Characteris-this of Soli Erosion in Small Wateshed

作　　者：史景汉[1] 刘汉喜[1] 

机构地区：[1]黄委会绥德水土保持科学试验站

出　　处：《中国水土保持》1990年第12期23-27,共5页Soil and Water Conservation in China

摘　　要：黄丘一区位于北纬36°41′～40°23′、东经108°39′～120°09′之间,面积70748km^2,是黄河多沙粗沙主要产区。研究该区土壤侵蚀特性和综合治理后的土壤侵蚀变化,对于制订水土保持规划和开展流域综合治理具有重要意义。本文根据有关自然综考及调查资料,对该区地理概况及小流域土壤侵蚀特征进行论述。The first Subzone of gullied rolling loess region,With an area of 70748 km^2,is the main source of coarse sediment entering the Yellow River.In this Subzone, the main stratums Covering on the ancient shallow valley and low mound are Lishi Loess,Wucheng Loess and Malan Loess formed in the Quaternary Period.Ann。 ual precipitation in this a rea ranges f rom 280 mm to 500 mm.sediment yield from the catchment concentrates in a short pe riod and the sediment output du ring one storm event occuUpies 52.6%～89.1% of the annual sediment load.Influenced by both water erosion and gravity erosion,annual sediment yield from the gullied atea in this subzone covers over 60% of the annual sedirnent yield in the whole catchment.The pa per systematically describes the ways of soil erosion in the sub-region and expounds the variation of erosion patterns and e rosion characteristics in different locations befo re and after control

关 键 词：小流域 土壤侵蚀特征 

分 类 号：S157.1[农业科学—土壤学]