小流域综合治理前后土地利用结构和土壤侵蚀强度变化研究

土地利用结构调整和减少土壤侵蚀面积、降低土壤侵蚀强度是小流域综合治理工程的主要效益,小流域综合治理前后土地利用和土壤侵蚀变化分析是评价工程实施效益的重要方面。以云贵鄂渝水土保持世行贷款/欧盟赠款项目重点监测小流域-盆古小流域为研究对象,基于治理前后的两期高分辨率遥感影像和eCognition、Arcgis软件,对盆古小流域治理前后的土地利用和土壤侵蚀变化情况进行了分析研究。结果表明:2008~2011年盆古小流域旱地、水田等面积减少,有林地和梯田等面积增加;小流域轻度侵蚀在有林地中分布最多,而轻度以上侵蚀主要分布在旱地中;另外,小流域土壤侵蚀这一期间整体呈现由强转弱的趋势,表明小流域综合治理工程取得了明显成效。

Study on the Land Use Structure and Soil Erosion Variation before and after the Small Watershed Comprehensive Management

Main benefits of the small watershed comprehensive management include the adjustment of the land use structure, reduction of the soil erosion areas and the reduction of soil erosion strength. The land use before ＆ after the small watershed comprehensive management and the soil erosion variation analysis are the important aspects in the as- sessment of the project implementation benefits. Based on the high - resolution RS images took before and after the management with the software such as the eCognition, Arcgis, the analysis and study was conducted on the land use and soil erosion variation before and after the management of the Pengu Small Watershed, that is under the Key Moni-toring Small Watershed of the World Bank Loan/EU Grant Project of Yunnan, Guizhou, Hubei and Chongqing Provinces. The results showed that from 2008 to 2011 the area of dry land and paddy land reduced while the areas of forest and terrace increased. Most of the slight erosion is located in the forest land, while the erosion level higher than slight erosion is mainly located in the dry land. In addition, the soil erosion of small watershed during the period appeared the trend of slowing down, that indicate the small watershed comprehensive management reached the obvious achievement.