关键词: 土壤侵蚀; 植被覆盖度; 空间尺度; 遥感影像; 岩溶区;

Abstract: To study the applicability of vegetation coverage at different spatial scales in soil erosion intensity discrimination, the vegetation coverage was calculated by using three remote sensing images of MODIS,Landsat8 and GF1 with different spatial resolutions.Combined with the bedrock bare rate, terrain slope and land use, the soil erosion strength was determined in karst areas, according to Techniques standard for comprehensive control of soil erosion and water loss in the karst region(SL461-2009).Differences of the calculation results of vegetation cover and soil erosion across spatial scales were compared.The results show that MODIS,Landsat8 and GF1 images can basically reflect the relative situation of vegetation coverage in the study area.The spatial trends are approximately the same, but there are some differences in local region.The vegetation coverage based on MODIS and Landsat8 images are roughly the same in each grade of distribution area, but that based on GF1 image is significantly different.The spatial distribution trend of soil erosion is similar to that of vegetation.The higher the resolution of vegetation coverage's image is, the more serious the soil erosion is.Soil erosion intensity based on GF1 image is the highest, followed by that based on Landsat8 image, the soil erosion intensity based on MODIS image is the lowest.Therefore, the selection of vegetation coverage factor is very important to soil erosion intensity discrimination in karst area and the scale applicability evaluation is required.

Key words: soil erosion; vegetation coverage; spatial scale; remote sensing image; karst area;