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对取自贵州西南部紫云县麦岗水库的沉积物柱芯MG1-1进行了包括SIRM、ARM、χlf、χfd、IRM-20mT和IRM-100mT等磁性参数的矿物磁性测量,并计算了ARM/SIRM、HIRM和IRM-100mT/SIRM。根据沉积物的这些矿物磁性特征,并结合137Cs、粒度、TOC、C/N分析结果,推测了麦岗水库流域在1960～2007年(47年)间的土壤侵蚀变化情况。研究表明:麦岗水库流域的土壤侵蚀强度变化虽然存在一些波动,但整体上呈现由强到弱到强再到弱的变化过程。结合降水资料和土地利用/土地覆被变化情况,探讨了影响土壤侵蚀变化的主要原因。结果表明,降水量对流域土壤侵蚀变化的影响不大,而人类活动,特别是土地利用的变化可能是引起流域土壤侵蚀变化的主要原因。
The magnetic measurements of minerals including magnetic parameters of SIRM, ARM, χlf, χfd, IRM-20mT and IRM-100mT were carried out for the sediment core MG1-1 taken from the Makang reservoir in Ziyun County, southwest Guizhou Province. / SIRM, HIRM and IRM-100mT / SIRM. According to the magnetic characteristics of these minerals in the sediment and the results of 137Cs, particle size, TOC and C / N analysis, the soil erosion change in the Makang reservoir basin was estimated from 1960 to 2007 (47 years). The results show that although there are some fluctuations in the changes of soil erosion intensity in the valley of Maigang Reservoir, the whole process of the changes from strong to weak to strong to weak changes. Combined with precipitation data and land use / land cover changes, the main reasons for the impact of soil erosion changes were discussed. The results show that precipitation has little effect on the change of soil erosion in the basin, but human activities, especially the change of land use, may be the main reason for the change of soil erosion.