基于GIS与RUSLE模型的喀斯特地区土壤侵蚀研究——以贵州省为例

目的]对贵州省土壤侵蚀进行快速定量研究,为土壤侵蚀治理工作和土地利用决策提供科学依据。方法]在GIS技术的支持下,利用日降雨量、土壤类型、土地利用、DEM,MODIS-NDVI等数据,结合RUSLE模型估算研究区土壤侵蚀量。结果]研究区的2010年年均土壤侵蚀模数为880.81t/(km~2·a),属轻度侵蚀。大部分区域主要以小于500t/(km~2·a)的微度侵蚀为主,占研究区总面积的59.60%。土壤侵蚀面积(轻度侵蚀以上)达71 164.14km~2,占总面积的40.40%。强度以上土壤侵蚀面积达10 431.60km~2,占总面积的5.91%,主要分布在研究区西北部和东北部,以及北部大楼山、武陵山、东南部苗岭以及西部乌蒙山等地势较高以及中东部乌江,西南部北盘江等河流流域。结论]林地、耕地和草地以及海拔在600~1 600m之间的区域是今后水土流失防治的重点区域。

Research on Soil Erosion in Karst Area Based on GIS and RUSLE Model- A Case Study in Guizhou Province

Objective] A rapid and quantitative study has been done on soil erosion in Guizhou Province in order to provide scientific basis for the management of soil erosion and land use decision.Methods] With the support of GIS technology and data on the rainfall, soil type, land use, DEM and MODIS-NDVI, we used RUSLE model to estimate of soil erosion.Results] The annual average soil erosion modulus of the study area was 880.81 t/km², which belongs to mild erosion. Most area belongs to the micro erosion with soil erosion modulus less than 500 t/(km²·a), which accounted for 59.60% of the total study area. Soil erosion area(above the mild erosion) reached 71 164.14 km², which accounted for 40.40% of the total area. The area above strong erosion level was 10 431.60 km², which accounted for 5.91% of the total area and mainly distributed in the northwest and northeast of the research area, and in the Northern Dalou Mountain, Wuling Mountain, Southeastern Miaoling Mountain and Western Wumeng Mountain with high altitude and middle east of Wujiang River, southwest of North Panjiang and other river basins.Conclusion] Woodland, farmland, grassland and region between elevation of 600~1 600 m is the key area for soil and water conservation in the future.