【摘要】 提出了土壤侵蚀综合指数(EI值)的新算法,并利用多项式方程模型法确定剧烈侵蚀强度的侵蚀模数中值为18700tkm-2a-1,还确定了各侵蚀等级的权重分值。利用新方法计算了南方红壤区476个县级行政单位(包括市和区,简称县,下同)在1996年和2002年两个年度的土壤侵蚀综合指数,在GIS支持下,分析了EI值的时空变化。从时间上来看,南方红壤全区的EI值从1986年的3.81降低至2002年的3.02,呈递减趋势,说明该时间段红壤区土壤侵蚀面积和强度都在向好的方向发展。从1996年至2002年5年间,红壤区476个县中,EI值增加的有163个,EI值减少的有285个,EI值保持不变的有28个,分别占红壤区总县数的34.2%、59.9%和5.9%。EI值减少的区域,主要分布在江西、福建和浙江3省,而指数增加的区域,主要分布在广东和湖南,特别是广东省,EI值增加的区域面积较大,说明土壤侵蚀较为轻微的广东省,近年来土壤侵蚀有加重的趋势。更多还原

【Abstract】 A new method is proposed to calculate integrated index of soil erosion(EI)and the mean soil erosion modulus for most serious erosion worked out to be 18 700 t km-2 a-1 by using the polynomial equation modeling method,and then the weight for each grade of soil erosion determined.Based on the EIs calculated with the new method,comparison was made between 1986,1996 and 2002 in soil erosion status of the whole red soil region in South China and of each of the 476 counties(cities)therein.Results show that the EI of the whole region decreased from 3.81 in 1986 to 3.02 in 2002,which suggests that soil erosion was declining in both area and intensity.The results also show that of the 476 counties(cities)in the region,163 increased,285 decreased,and 28 remained unchanged in EI in the period from 1996 to 2002.Areas with decreasing EI were mostly distributed in Jiangxi,Fujian and Zhejiang Provinces,while areas with increasing EI in Guangdong and Hunan Provinces.Particularly in Guangdong Province,the area with increasing EI was larger in acreage,suggesting that though it used to be slight in soil erosion,the situation has been getting worse and worse in the recent years.更多还原