摘要
黄土丘陵沟壑区水土流失非常严重。近年来退耕还林政策的实施对土壤侵蚀及水土流失有根本的影响。为了解该区水土流失情况,以陕北安塞县马家沟流域为例,以2008年土地利用实地调查及数据为基础,采用水利部颁《土壤侵蚀分类分级标准》(SL190-96),计算流域土壤侵蚀模数并分析其空间分布。研究结果表明:在2008年土地利用和土地覆被条件下,马家沟流域土壤侵蚀模数估算值为5700t/(km2·a)。各侵蚀级别面积占流域分布比例呈正态分布,中度侵蚀级别占流域面积的53.65%,然后是强度、轻度级别,为17.23%、14.64%,极强度、微度和剧烈侵蚀面积较少,为9.2%、4.16%和1.12%。流域上、中、下游侵蚀级别的分布格局受流域地形地貌特征影响很大。上中游各侵蚀级别分布格局与全流域非常相似。下游则呈现微度、强度侵蚀集中,轻度、剧烈侵蚀较少的格局。
Soil erosion in Loess Plateau is very serious.In recent years,implementation of the policy of returning farmland to forest has a fundamental impact on soil erosion.In order to learn the situation of soil erosion in this area,taking the Majiagou gully which lies in the north part of Shaanxi province,the typical hilly and gully loess region as the example,based on land use filed survey and data in 2008,using Standards for classification and gradtion of soil erosion（SL190-96）from Ministry of Water Resources,this paper calculated soil erosion modulus of watershed and analyzed their spatial distributions.It is shown that soil erosion modulus in Majiagou was 5 700t/（km2·a）under the conditions in the land use and land cover.The areas of classification erosion levels present normal distribution.The moderate erosion takes 53.65%area of watershed,the intense and slight levels take 17.23%,14.64%,respectively.Severe,weak and extreme severe level take less erosion area,for 4.16%,1.12%and 9.2%.The erosion distributions of upper,middle and downstream area are affected by terrain geomorphology.In upper and middle area,it matches the whole watershed erosion distribution.In downstream area,most area erosion level is weak or intense,gentler and severe levels concentrate less in proportion.
出处
《水土保持研究》
CSCD
北大核心
2010年第4期29-33,共5页
Research of Soil and Water Conservation
基金
中国科学院西部行动计划(二期)项目"黄土高原退耕还林(草)环境效应与效益评价"(KZCX2-XB2-05-03)
关键词
土壤侵蚀
空间分布
黄土丘陵区
soil erosion
spatial distribution
hily-gullt region
