Pollution Assessment Of Heavy Metal Elements Of Chongqing Metropolitan Based On GIS In Soil

Chongqing terrain, complex topography, large spatial variability of different uses, different input levels, different management models have an impact on soil quality, combined with the region factories, enterprises, regardless of the type of pollutants generated or the intensity of human impact, are very prominent, and soil contamination is a serious problem. Based on the Chongqing metropolitan area of investigation and evidence collection topsoil, research the Chongqing metropolitan area of heavy metal pollution in soil. The 1772 study of the surface soil, and more than 400 deep soil samples and eight kinds of heavy metal elements in the data processing, analysis the following conclusions:(1) Hazen curve for this paper from the background of the area and the deep value of heavy metals in soil on average more consistently, and in line with the actual situation of the area for future study of the surface soil in Chongqing to provide the basic data.(2) 8 kinds of heavy metal elements in the area on the west side from the second row with a more even distribution of the Triassic (T) near the shallow strip of heavy metal elements in soil are higher, that is, near the town of Jindaoxia, the area in the north-east side, in addition to Pb, the other elements in this region are high-value range. However, eight kinds of heavy metal elements from the spatial distribution map can be seen that eight kinds of heavy metal elements in rural areas than urban low-, from the chart to graph the performance of the central west, and high values occur when plaque, which in a certain extent that elements of the city Invasive than the outer suburbs of the source of serious, although the addition of As than higher levels of heavy metals in all parts of斑块状into distribution, but from the distribution map can be seen with the strata of the distribution of inheritance, at the same time with the water system, topography, as well as factors such as human activities have a definite impact. (3) National Soil environmental quality standard for metropolitan area, such as soil content of heavy metals in the evaluation: Cd and Hg pollution is relatively serious, and pollution were surface-like posture, is the metropolitan area in the eight kinds of heavy metal pollution of soil pollution on the largest the two kinds of elements. 83.97% of samples of the soil sampling points have been different levels of Cd pollution elements; of other heavy metals, Cr, Pb, Zn metal pollution rate reached 13.32 percent, 13.77 percent, 13.32 percent; the study area in the North West Frontier of Jindaoxia that is near the town of eight kinds of heavy-metal contents are high, and here is the Triassic, which would indicate that high levels of heavy metals in here one of the most important reason is that the quality of heavy metals in their home high soil parent material has a very good inheritance, so in a single element map the spatial distribution of heavy metals in the high side is the right to be found.(4) In this paper, Nemerow index method selected, the potential eco-index, index of geoaccumulation law, pollution load index, which index the pollution load of heavy metal elements in the evaluation of the degree of pollution is rare. In calculating the index, after some more for the pollution of heavy metals in rare degree. In the calculation of the index, after all, using the space distribution of heavy metals in the same way the study area produced a single element of heavy metal pollution evaluation plans and evaluation of composite index maps and map interpretation, that is, the four evaluation methods come to the conclusion the same, As, Cr, Cu, Hg, Ni, Pb mainly to clean area Cd mainly to light pollution in the evaluation of potential ecological Cd is moderately polluted, Nemerow composite index evaluation of the study area to clean up the area and light pollution the main index comprehensive evaluation of potential ecological light -moderate pollution mainly still as a result of the Triassic (Jindaoxia town) of the content of heavy metals in soil are high-value, therefore, in the evaluation of pollution, natural pollution in the region on high. Evaluation of such results to the actual situation of Chongqing metropolitan area have little access. This further illustrates that the results of the evaluation as well as the availability of scientific.