昆明市松华坝水源区小流域土壤侵蚀分析

以1993-2009年松华坝水源区及昆明市的气象资料、2009年土地利用资料、第二次全国土壤普查资料、水源区牧羊河小流域的径流和泥沙观测资料为基础,用SWAT模型模拟分析了牧羊流域土壤侵蚀的空间差异。结果表明：牧羊河小流域输沙在年际上表现为与年降水量和输沙量峰谷变化具有较好的一致性,在年内表现出,输沙主要集中在6-9月；空间上牧羊河土壤侵蚀模数多年平均值介于21.4~4 586.5 t/(km²·a),且以中轻度为主,土壤侵蚀模数的空间变化与土地利用类型和地形坡度密切相关；土壤侵蚀模数与降水在年际变化上有较好的一致性。这一研究可为水源区土壤侵蚀空间分布的掌握和估算,以及制定有针对性的水土保持措施提供重要的理论依据。

Spatial Difference of Soil Erosion in the Small Watershed of Songhuaba Water Source Area in Kunming City

Spatial difference of soil erosion in Muyang river watershed was analyzed by SWAT hydrological model. The research was carried out based on the meteorological data from 1993 to 2009 and land use data in 2009 in Songhuaba water source area and Kunming city, and the second national general soil survey data as well as the observed data of runoff and sediment discharge in the small watershed. Results showed that the interannual peak and valley values of precipitation and sediment discharge were in good coherence. While within the year, the sediment discharge occurred mainly from June to September. The average soil erosion modulus varied from 21.4 t/(km²·a) to 4 586.5 t/(km²·a), indicating that the soil erosion is mainly between middle to moderate levels. The spatial variation of soil erosion is closely related with land use type and topography and slope angle. Interannual variations of soil erosion modulus and precipitation were also in consistency. The research provides basis for estimating the spatial distribution of soil erosion and making targeted conservation measures.