Spatial Distribution And Source Analysis Of Heavy Metals In The Interface Of Soil-water Pollution Flow In Hongqi Mining Area

With the rapid development of national industry,the demand of mineral resources to social is soaring,which leads to the more frequent mining exploitation.Heavy activities of industry and mining have become an important source of heavy metals in the soil which result in an ecological imbalance and serious environmental pollution.Activity of industry and mining makes a lot of heavy metals appeared from the depths of the earth to the surface and diffused which caused pollution of the ecological environment.So that doing the investigation and analysis of pollution source and spatial pollution characteristics have a great significance for preventting the pollution of heavy metal in soil and improving the quality of soil environment.The research area is located near a mine in Xiangtan city.Six kinds of heavy metals of Mn,Zn,Cu,Pb,Ni and Cd in soil were collected and measured after distributing sampling points evenly and determining the coordinates of the sample points.Finally,making use of factor analysis-multiple linear regression analysis method and statistical analysis method to analyze and process data.The results are as follows:?1?According to the correlation analysis of heavy metals on the surface of the soil and water boundary in the research area,the highest correlation between heavy metal elements was Pb and Mn,Zn and Cu,their correlation coefficient counts 0.605 and 0.609respectively.In addition,the correlation coefficient of Mn and Ni,Mn and Zn,Cd and Zn,Cu and Pb is greater than 0.5 so that their correlation are high.The correlation of Mn and Cd,Zn and Ni,Zn and Pb,Pb and Cd are in general which's correlation coefficients are0.499,0.436,0.434 and 0.456.The correlation among other heavy metal elements is poor.?2?The main sources of six kinds of heavy metals are divided into three main sources.The first pollution is caused by industrial activities such as ore mining,smelting,mining,waste liquid and other industrial activities.The second Pollution is caused by transportation in the mining area.The Third Pollution is caused by agricultural activities and human life,such as sewage irrigation and other pollution.Then,analyze the source of heavy metals in the study area with the method of multiple linear regression analysis quantitatively by SPSS.According to the analysis results,the contribution rate of industrial pollution is 43,51%,the pollution contribution rate of transportation is 39,26%,and the pollution contribution rate of agricultural activities and human activities is 17.23%.?3?Doing Half-variable function fitting and analyzing spatial correlation analysis to heavy metals by GS+.The analysis shows that the ratio of C₀/C₀+C to Mn element is 0.39,Ni is 0.50,Cu is 0.12,Zn is 0.12,Cd is 0.21,Pb is 0.37.The ratio of Mn,Ni and Pb are between 0.25⁰.75 which shows that spatial correlation of the three elements are medium.The ratio of Zn,Cu and Cd is between 0⁰.25 which shows that spatial correlation of the three elements are strong.?4?Doing inverse distance weighting,Kriging and RBF neural network interpolation to the six element by GIS.Then obtain the best interpolation method of each heavy metal by doing cross validation to the three kinds of interpolation which come to the result that the best interpolation method of Mn,Ni,Cu and Cd are RBF neural network,for Zn and Pb are Kriging.?5?The spatial distribution characteristics of heavy metal elements are obtained after the optimal interpolation by using GIS software.The analysis shows that the distribution of the elements Mn,Ni and Pb are similar which all have higher content of heavy mental in the east and decrease from east to west.According to the field investigation,there are a large number of tailings,smelting mines and mines which thows that the main source of Mn,Ni and Pb element are local activities of industrial and mining.The distribution of of Cd element is relatively high in the surrounding area and relatively small in the central area.According to the field investigation,there are more areas of residence and farmland around the research,so that the local activity of agriculture is the main source of Cd element.The distribution of Cu and Zn is similar which present a decreasing trend from the center to the surrounding area.According to the field investigation,the smoke vent in the mining area maybe the source of Cu and Zn.