基于信息熵的土壤Cr含量空间分布与土地利用空间相关性研究

    Spatial Distribution of Chromium Content in Soil and Its Spatial Correlation With Land Use Type Based on Information Entropy

    • 摘要: 土壤中Cr元素是典型的有毒有害重金属元素,其在土壤中的含量与自然条件和人类活动有着密切联系,定量研究土壤Cr含量与人类活动之间的相关关系,可为区域重金属污染防治方案制定和治理决策提供参考。在收集土地利用类型和土壤重金属含量等资料的基础上,基于GIS空间分析功能,获得江宁经济技术开发区土壤Cr含量空间分布;引入信息熵概念,建立定量研究土壤Cr含量与土地利用类型之间相关性的方法。结果表明:从定性上来看,研究区域土壤Cr含量空间分布呈较明显的空间分异;从定量上来看,研究区域土壤Cr含量与土地利用类型之间的空间相关系数K=0.13,两者之间存在一定的空间相关性,但K值远小于1,说明土地利用类型不是影响土壤Cr含量的唯一因素或主导因素。应用该方法时应注意变量的空间尺度适用性,若两个变量在某一空间尺度上均呈现较明显空间分异,则该方法适用,且数据精度越高,得到的分析结果就越可靠;若其中一个变量或两个变量在其研究尺度上无明显空间分异,则采用该方法计算的相关度将趋近于0。

       

      Abstract: Chromium in soil is a typical toxic and harmful heavy metal element, and its content in soil is closely related to natural conditions and human activities. A quantitative spatial correlation analysis between human activities and Cr content in soil will provide references for prevention programs and governance decisions of regional heavy metal pollution. Based on the data collection of land use types and heavy metal content in soil, the spatial distribution of chromium content in the soil of Jiangning Economic and Technological Development Zone was obtained based on the GIS spatial analysis function. By introducing the concept of information entropy, a quantitative approach studying on the correlation between chromium content in soil and land use types was established. The results show that: qualitatively, the spatial distribution of chromium content in soil shows obvious regional differentiation in the study area; quantitatively, the spatial correlation coefficient K of chromium content in soil and land use type was 0.13 in the area, and there is a certain spatial correlation between them. But the K value is far less than 1, indicating that the land use type is not the only factor or the dominant factor affecting the chromium content. When applying this method, attention should be paid to the spatial scale applicability of variables. If both variables show obvious spatial differentiation on a certain spatial scale, the method is applicable, and the higher the data accuracy, the more reliable the analysis results obtained; If one or two variables have no obvious spatial differentiation on the research scale, the correlation calculated by this method will approach zero.

       

    /

    返回文章
    返回