不同降雨带上的土壤侵蚀状况分析

利用遥感和地理信息系统技术对我国不同降雨量等级下的土壤侵蚀情况进行了分析 ,结果表明 ,轻度以上水蚀的百分比和水蚀综合指数的最高值都出现在降雨量为 2 5 0～ 40 0 m m的半干旱、农牧交错区的带上 ,分别为 5 5 .7%和 182。风蚀综合指数、冻融侵蚀综合指数和土壤侵蚀综合指数的最高值分别为 6 40 ,192和 44 7,均出现在降雨量小于 2 0 0 mm的干旱地带上。在降雨量大于 16 0 0 mm的带上不存在冻融侵蚀。在湿润、潮湿和过湿的地带上主要以水蚀为主 ,均占 96 %以上。在半湿润地带上 ,水蚀也占优势 ,占 76 .1%。在半干旱地带上 ,水蚀、风蚀和冻融侵蚀接近于各占 30 %。在干旱地带上 ,以风蚀为主 ,占 5 8.6 %。

Analysis of Soil Erosion Under Different Precipitation Condition

The soil erosion under different precipitatio n was analyzed byusing remote sensing and geographical information system techn ologies. The results show that the maximum of percentage of water erosion above light and water erosion index take place in the annual precipitation between 250 mm and 400 mm, and the maximum of the wind erosion index, the frozen erosi on index and the soil erosion index all take place in the annual preci pitation under 200 mm. There is no frozen erosion in the precipitation above 1 6 00 mm. Water erosion dominates in the region of annual precipitation from 800 mm to 1 000 mm, 1 000 mm to 1 600 mm , and above 1 600 mm, all accounting for above percent 96. In the region of the precipitation from 400 mm to 800 mm, water er osion, wind erosion and frozen erosion respectively account fo r closely percent 30. Wind erosion dominates the region of precipitation under 200 mm。