2000—2015江淮分水岭区域土壤侵蚀动态变化

Dynamic changes of soil erosion in Jianghuai watershed area from 2000 to 2015

基于GIS和RS技术,利用江淮分水岭2000年、2005年、2010年、2015年4期遥感影像数据,计算并对比该区域4期的土壤侵蚀量,达到对江淮分水岭土壤侵蚀时空动态监测。结果表明:1)江淮分水岭区域土壤侵蚀空间分布主要为皖西山地丘陵区,皖东环滁低山丘陵地带,微度和轻度侵蚀的土壤面积占总面积的99%以上。2)江淮分水岭区域15a间土壤侵蚀模数总体下降14.21t/(km2·a),各等级土壤侵蚀面积向微度侵蚀转移,土壤侵蚀状况总体发生好转。3)15a间江淮分水岭区域土地利用类型转变明显,耕地面积减少2 208.17km2(7.23%),林地、水体面积分别增加133.76km2(2.80%)、552.34km2(15.71%)。植被覆盖度的提高和水域面积的增加是土壤侵蚀改善的根本因素。

Based on GIS and RS technology,the four remote sensing image data of Jianghuai watershed2000,2005,2010 and 2015 were used to calculate and compare the soil erosion of the region,to achieve the goal of temporal and spatial dynamic monitoring of soil erosion of the Jianghuai watershed.The results show that:(a)The spatial distribution of soil erosion in the Jianghuai watershed area is mainly in the hilly area of west Anhui and around the Chuzhou.In addition,the soil area of mired and mild erosion accounts for more than 90 % of the total area.(b)During the 15 years,the total soil erosion modulus of the Jianghuai watershed decreased by 14.21 t/(km2·a).The soil erosion intensity of each grade was transferred to the micro erosion,and in better circumstances.(c)The change of land use type in the Jianghuai watershed in 15 years is obvious.The cultivated land area decreased by 2208.17 km2(7.23%).The woodland and water area increased by 133.76 km2(2.80%)and 552.34 km2(15.71%),respectively.The improvement of vegetation coverage and the increase of water area are the fundamental factors of soil erosion improvement.The result can provide the scientific basis for the improvement of soil erosion in the Jianghuai watershed area.