胜利矿区土壤养分空间变异特征与影响因素

Spatial Variability and Influencing Factors of Soil Nutrients in Shengli Mining Area

研究矿区土壤养分空间变异特征对矿区土地复垦与生态保护具有重要意义。选取胜利矿区土壤作为研究对象,基于地统计学和GIS技术分析土壤养分的空间变异性,并探讨地形因子和土地利用类型对其影响。结果表明:研究区土壤pH、有机质、速效氮、有效磷、速效钾平均含量分别为8.07、21.59 g/kg、82.91 mg/kg、8.21 mg/kg、257.34 mg/kg;除pH属于弱变异外,其他养分均属于中等强度变异;各项养分指标均具有一定的趋势效应。pH的最适模型是球面模型,有机质、速效钾的最适模型是线性有基台模型,速效氮、有效磷的最适模型是指数模型。pH、有机质、速效氮表现为中等空间自相关性;有效磷、速效钾呈弱空间自相关性。pH由中部向四周逐渐降低;有机质、速效氮高值区集中在西部高程较大的位置,低值区分布在受人类扰动较强的中东部;有效磷、速效钾没有呈现一定的分布规律。坡度、坡向、高程、地形湿度指数是造成土壤养分格局差异的主要地形因子;从土地利用方式看,采矿扰动是养分含量较低的重要原因,矿业用地养分含量显著低于耕地和草地。

It is of great significance for the land reclamation and ecological protection of mining areas to study the spatial variability characteristics of soil nutrients in the mining areas.In this paper,based on the geostatistics and GIS techniques,the spatial variability of soil nutrients and the effects of topographic factors and land use types on the spatial distribution of soil nutrients were studied in the Shengli mining area.The results showed that the average values of pH,soil organic matter,available nitrogen,available phosphorus and available potassium were 8.07,21.59 g/kg,82.91 mg/kg,8.21 mg/kg and 257.34 mg/kg,respectively.pH showed a weak variation while other soil indexes showed the moderate variation.All soil indexes had a certain trend effect,the spherical model was optimal for pH,the linear platform model was optimal for organic matter and available potassium,and the exponential model was optimal for available nitrogen and phosphorus.There were moderate spatial autocorrelation of pH,organic matter and available nitrogen;but the spatial autocorrelation of available phosphorus and potassium were weak.pH decreased gradually from the middle to the four sides,organic matter and available nitrogen were higher in the west region with high elevation,but lower in the central and eastern regions under strong disturbance of human beings,whereas available phosphorus and potassium were irregularly distributed.Slope,aspect,elevation,and topographic wetness index were the main topographic factors contributing to the pattern differences of soil nutrients.From the point of view of land use,mining disturbance is the important reason for low nutrient content,the nutrient content of mining land is significantly lower than that of farmland and grassland.