喀斯特石漠化地区土地利用变化对水土流失的影响——以贵州省务川仡佬族苗族自治县为例

为了分析喀斯特石漠化地区土地利用、石漠化、水土流失空间分布与面积变化趋势,以石漠化现象较为严重的贵州省务川仡佬族苗族自治县为研究区,利用2000,2005,2010,2015年遥感影像获取务川县土地利用类型空间分布与估算石漠化等级空间分布,并运用修正的通用水土流失方程建立的喀斯特地区水土流失方程进行水土流失计算。结果表明:土地利用变化对石漠化与水土流失有显著影响,林地、草地面积的增加显著降低了水土流失量。务川县2000～2015年林地面积增加80.37 km~2,旱地面积减少91.69 km~2;2010～2015年重度石漠化面积减少263.73 km~2;2000～2015年微度侵蚀面积增加636.13 km~2,轻度侵蚀面积减少157.21 km~2,中度侵蚀面积减少356.28 km~2,强烈侵蚀面积减少111.23 km~2。务川县2000～2015年实施的退耕还林与石漠化治理工程使得水土流失现象有了明显的好转。

Effect of land use change on soil erosion in Karst rocky desertification area: case of Wuchuan County,Guizhou Province

In order to analyze the change trend of land use, rocky desertification and soil erosion in Karst rocky desertification area, Wuchuan County in Guizhou Province was selected as the research area. Remote sensing image data in 2000, 2005, 2010 and 2015 was collected and used to obtain the spatial distribution of land use types and estimate the spatial distribution of rocky desertification levels in Wuchuan County. Water loss equations adapted for the Karst area were established by modifying general soil and water loss equations. The land use, rocky desertification, water and soil loss spatial distribution and area change trends were studied. The results showed that land use change had a significant impact on rocky desertification and soil erosion, and the increase of forest land and grassland area significantly reduced the amount of soil erosion. Forest area increased by 80.37 km2,while the dry land area decreased by 91.69 km2 from 2000 to 2015.Severe rocky desertification area decreased by 263.73 km2 from 2010 to 2015. Slightly eroded area increased by 636.13 km2 and lightly eroded area decreased by 157.21 km2 from 2000 to 2015.The moderate erosion area decreased by 356.28 km2,and the severe erosion area decreased by 111.23 km2.After the implementation of the projects of returning farmland to forests and rocky desertification in Wuchuan County from 2000 to 2015, the soil erosion phenomenon improved significantly.