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在乌鲁木齐市,按不同用地类型和空间分布的均匀性,采集45个表土样品。分析了土地利用类型引起的市、郊区土壤磁性参数的差异,研究了土壤磁性参数空间变异性和分布特征,并初步探讨了其人为影响因素。结果表明:除了χFD以外,市区土壤χLF、Soft IRM和HIRM均值高于郊区。研究区土壤以亚铁磁性矿物主导,并伴有少量不完全反铁磁性矿物,市区土壤超顺磁性矿物颗粒含量低于郊区。土地利用类型是导致市、郊区土壤磁性参数差异的重要因素。从变异系数看,4种磁性参数都属于中等变异程度。空间变异性分析表明,各磁性参数的最优拟合模型是球状和指数模型,变程介于15~18km之间。从Q值结果看,χFD、Soft IRM属于高度空间变异性,χLF为中度变异性,HIRM变异程度最低。空间分布特征表明,χLF、Soft IRM值基本以工业区为中心,向外围递减。χFD分布趋势大致与其他参数相反。HIRM分布呈东、西部高,中部低且向南北方向递减的趋势。人为因素是影响乌鲁木齐市土壤磁性空间变异的关键因素。
In Urumqi, 45 topsoil samples were collected according to the uniformity of land use types and spatial distribution. The differences of soil magnetic parameters in urban and suburban areas caused by land use types were analyzed. The spatial variability and distribution characteristics of soil magnetic parameters were studied, and the human factors were also discussed. The results showed that in addition to χFD, the average values of χLF, Soft IRM and HIRM in urban soils were higher than those in suburbs. The soil in the study area is dominated by ferrous magnetic minerals with a small amount of incompletely antiferromagnetic minerals. The content of superparamagnetic mineral particles in urban soils is lower than that in the suburbs. The type of land use is an important factor that leads to the difference of magnetic parameters of soils in suburban and rural areas. From the coefficient of variation, all four kinds of magnetic parameters belong to the medium degree of variation. Spatial variability analysis shows that the best fit model of each magnetic parameter is the spherical and exponential model with a range of 15 ~ 18km. From the Q value results, χFD, Soft IRM belong to high spatial variability, χLF is moderate variability, HIRM variability is the lowest. Spatial distribution characteristics show that χLF and Soft IRM values are basically reduced to the periphery with the industrial area as the center. The trend of χFD distribution is roughly opposite to other parameters. The HIRM distribution tends to be higher in the east and west, lower in the middle and decrease toward the north and south. Human factors are the key factors affecting the spatial variability of soil in Urumqi.