京津水源区小流域土壤侵蚀及其空间分异  

Soil Erosion and Its Spatial Differentiation of a Small Watershed in Water Source Areas of Beijing City and Tianjin City

作　　者：江青龙[1] 谢永生[1,2] 张应龙[1] 张义[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《水土保持通报》2011年第1期249-255,F0003,共8页Bulletin of Soil and Water Conservation

基　　金：水利部公益性行业专项经费项目"冀北山区生态输水小流域治理模式与关键技术"(200901051);中国科学院知识创新工程重大项目"耕地保育与持续高效现代农业试点工程"(KSCX-YW-09-07);中国科学院农业项目(kscx2-yw-N-46-04);国家科技支撑计划项目(2006BAD09B10);国家科技支撑计划项目(2006BAD15B01-03)

摘　　要：针对京津水源区生态环境脆弱,水土流失空间分异大,突发性强等问题,选择河北省滦平县西北沟小流域为研究对象,利用气候、土壤、地形、土地利用及植被盖度等数据,运用GIS和RUSLE的方法对小流域土壤侵蚀强度及其空间分异特征进行了研究。结果表明,流域多年平均侵蚀模数为3 816.835t/(km2.a),属中度侵蚀;潜在侵蚀模数为31 583.150t/(km2.a),是现实侵蚀模数的8.28倍;不同土地利用方式中,零星分布的大坡度坡耕地侵蚀强度最大,其次为高度风化,坡度较大的退化荒草地,退化荒草地面积占流域总面积的59.38%,侵蚀量占总量的88.48%,是最主要的泥沙来源地;不同坡度土壤侵蚀强度随坡度加大而显著增加,流域坡度>25°的面积约占流域总面积的1/3,侵蚀量约占2/3;不同坡向的土壤侵蚀空间分异也十分明显,表现为正阳坡>半阳坡>半阴坡>正阴坡>平地。In the water source areas of Beijing City and Tianjin City,ecological environment is highly fragile,and soil and water loss often exhibits strong spatial variability and occurs unpredictably.Along with data of climate,soil,terrain,land use and vegetation coverage,soil erosion and its spatial differentiation were studied based on the revised universal soil loss equation（RUSLE） model and geographic information system（GIS）,in Xibeigou watershed of Luanping County,Hebei Province.The results show that the annual average rate of soil erosion was 3 816.835 t/（km2·a）,classified as middle-grade erosion.Annual average of potential soil erosion was 31 583.15 t/（km2·a）,about 8.28 times of the former.Meanwhile,soil loss was obviously spatially differentiated.Among different land uses,sporadically distributed farmlands with steep slopes had the strongest soil erosion intensity,and next to it was highly weathered and degraded grassland＇s,which accounts for 59.38% of the total area of the watershed and 88.48% of the total sediment as the main source of the soil loss.With the increasing slope,the soil erosion intensity increased markedly.Approximately one third of the total area of this region has a slope degree higher than 25°,while this proportion contributed two third of soil loss.Soil losses also differed among lands of various aspects,as in order of sunny slope half-sunny slope half-shady slope shady slope flatland.

关 键 词：京津水源区 地理信息系统(GIS) 修正通用水土流失方程(RUSLE) 土壤侵蚀 

分 类 号：S157.1[农业科学—土壤学]