基于GIS和RUSLE的星云湖流域土壤侵蚀空间分布特征

研究星云湖流域水土流失,揭示水土流失的空间分异规律,能够为该流域水土流失治理提供理论基础。根据典型的土壤侵蚀RUSLE模型,选用能体现流域特点的估算模型分别计算出了降雨侵蚀力因子、土壤可蚀性因子等五个因子,运用ArcGIS空间分析工具计算出星云湖流域土壤侵蚀模数,并统计分析流域的侵蚀状况。结果表明:星云湖流域土壤侵蚀以微度侵蚀为主;剧烈侵蚀主要分布在流域的北部和东部区域,其中,子流域中主要集中在螺浉河小流域和北部坝区小流域,乡镇中主要在路居镇,用地类型主要为其他用地和耕地;其次流域内平均侵蚀量最大的地形主要集中于25°~35°之间,以半阴坡坡向为主。应加强螺浉河小流域和北部坝区小流域的水土流失治理,坡度大于25°和坡向为半阴坡的区域水土流失较为严重,不适宜耕种,应加强退耕还林工作,优化未利用地的管理,有针对性地对流域内水土流失进行治理与防治。

The spatial distribution of soil erosion in the lake basin based on GIS and RUSLE

The study on soil erosion condition about xingyun lake basin can provide theoretical basis for water loss and soil erosion control in river basin, this paper uses the typical soil erosion model, RUSLE model, to evaluate the soil erosion condition of xingyun lake basin. Factors were calculated trough different models. The results show that micro erosion is the principal soil erosion type in xingyun lake basin , and sever erosion, which is mainly located in the northern and eastern regions of the basin, has the largest proportion of soil loss which is more than 50%; as regards sub-basin, township and land use type ,the soil erosion is most severe in luoshihe basin and north dam basin, lujv town, unused land and cultivated land ,respectively; besides, the largest mean soil loss is in the topography whose slope mainly between 25 and ~35 degrees, and most of which are half shady slope. Water and soil erosion control in aforementioned sub-basins should be strengthened. The areas where slope is greater than 25 degrees and the areas of half shady slope should return farmland to forests because severe land erosion makes them not suitable for farming. Furthermore, we should optimize the management of unused land and prevent water and soil erosion pertinently in the basin.