山西耕作土壤样品磁性空间分异及其环境意义

本文分析了山西高原土壤耕作层(0-20cm)25个样品的磁性,用GIS空间分析方法,得出土壤磁化率平面分布等值线图和空间三维模型。磁化率空间分布机理如下:首先,强烈的人为影响使土壤中磁性矿物人为来源占有重要地位。第二,土壤磁性矿物以亚铁磁性的磁铁矿和磁赤铁矿为主导。第三,土壤磁化率极值差及其与母质之间的差异均受广泛而较均一的黄土母质的影响。第四,晋西北和晋中等区域出现土壤磁化率高值区域。第五,人为作用强烈影响掩盖了气温、降水等气候因子对土壤磁化率的作用。

A Study on theMechanism of Spatial Distribution and Environmental Meanings of Magnetic Characters of Farming Soil Samples in Shanxi

Magnetic susceptibility and other parameters were analyzed for 25 surface ( 0- 25cm) cultivated soil samples from Shanxi highland, by GIS ( geographic information system) spatial analysis, achieved the contour map of magnetic susceptibility and three dimension model. The distribution mechanism of magnetic susceptibility as follows: first, magnetic minerals from human activity in soils play an important role; secondly, soil magnetic minerals are mainly ferrimagnetism, i. e. magnetite ( Fe3O4)& maghemite( Fe2O3) , the crystal sizes of magnetite are single domain( SD) , Multi- domain(MD) &. Superparamagnetic( SP) , concurrence; thirdly, effects from the same parent material- - loess, so soil magnetic susceptibility has less difference ( maximum and minimum) in this area; forthly , the special parent material and energy/ heavy chemistry industry distribution affect soil magnetic susceptibility, so higher value area in the northwest and middle; lastly, human activity effect is so intensive that the influence of air temperature, precipitation, etc. on soil magnetic susceptibility was masked.