基于GIS和CSLE的陕西省土壤侵蚀定量评价方法研究

通过对陕西省土壤侵蚀的定量评估,探索省域尺度上土壤侵蚀定量评价制图方法,以期为第四次全国土壤侵蚀普查提供技术支撑.利用陕西省日降雨数据、土壤类型图、土地利用图、DEM、植被覆盖图,选择CSLE模型.在ArcGIS平台上计算研究区2006年土壤侵蚀量,并与水利部标准评价结果进行对比分析.探索了坡度坡长变换对土壤侵蚀的影响.定量化的评价结果能较好的反映气候,土壤及水保措施对土壤侵蚀的影响,比水利部标准评价结果更能反映实际侵蚀.坡度坡长变换后对土壤侵蚀有明显影响.在GIS支持下,通过土壤侵蚀模型进行定量评价,可高效、客观反映土壤侵蚀情况及其主要影响因子,对区域治理和有关决策有极其重要参考价值.为了准确真实的反映土壤侵蚀程度,必须进行坡度坡长变换.

GIS and CSLE Based Quantitative Assessment of Soil Erosion in Shaanxi, China

The purpose of this study is to explore the mapping methods for quantitative assessment of soil erosion in the provincial scale with the hoping of providing some technical support to the 4th national soil erosion survey by quantitative assessment of soil erosion in Shaanxi province. We collected the daily precipitation data, soil type map, land use map, digital evaluation map(DEM) and vegetation cover graphs of Shaanxi province, with the using of CSLE model to calculate the soil loss of this study area in 2006, and compared the results with the standard evaluation results of Ministry of Water Resources. We also explored the impact of transformation of slope and slope length in soil erosion. The results of quantitative assessment can reflect the influence of soil, climate and measures of soil and water conservation on soil erosion more accurately than the standard evaluation results of Ministry of Water Resources. There was a significantly effect after the slope and slope length had been transformed. The quantitative assessment by a soil erosion model and with the support of GIS, can reflect the soil erosion and its key impact factors efficiently and objectively. There is an extremely important reference value in regional governance and decision-aking. In order to reflect the true extent of soil erosion accurately, we must transform the slope and slope length during the evaluation.