基于RS和GIS的元阳县水土流失变化研究

以RS和GIS技术为支撑,采用USLE模型,以ETM+为遥感数据源,结合降雨、植被、土壤类型及DEM等数据,提取相关因子,得到1999、2005和2010年元阳县的水土流失分等图。结果表明,元阳县流失区域主要分布于低海拔地区,集中分布于河流两岸。极强烈流失及剧烈流失主要发生在工矿用地和坡度大于35°的坡耕地。1999～2010年微度和轻度侵蚀区面积持续减少,年均减少2.60%,约57.03 km2。1999、2005、2010年中度以上侵蚀面积分别占总面积的36.53%、56.74%、62.57%,呈现明显的上升趋势。结合元阳县水土流失空间变化特征,提出了加强林草植被建设、发展保护性农业耕作和加强执法力度,加大法制宣传教育,依法防止和控制新的水土流失等水土保持建议。

Study on Change of Soil Erosion in Yuanyang County Based on RS and GIS

The study was conducted based on the data of ETM+,combined with the rainfall,vegetation,soil type and DEM data of Yuanyang County,with the support of the RS and GIS techniques and using the USLE model.By extracting the relevant factors,three soil erosion grading chart were got during 1999,2005 and 2010 in Yuanyang County.Results were showed as follows: The loss areas are mainly distributed in low-lying areas and concentrated along the banks of the river of Yuanyang County.The overwhelming loss and severe loss areas are mainly the mining sites and slope farmland with the slope of greater than 35 °.The micro-degree and slight erosion area continued to decrease,with an average annual decrease of 2.60%,about 57.03 km2 in the past 10 years.The total area of moderate erosion accunted for 36.53% in 1999,56.74% in 2005 and 62.57% in 2010,showing a clear upward trend.Combined with the soil erosion spatial variation characteristics,several suggestions were put forward,including strengthen the establishment of vegetation,develop conservation farming and strengthen law enforcement,increase law publicity and education,prevent and control soil erosion according to the law.