Study On Spatial Distribution And Economic Loss For Soil Heavy Metals In Chengdu Plain

In order to assess the amount and spatial distribution of soil heavy metals in Chengdu plain, 142samples were collected from soil, around roadside soil and riverside soil of 7 districts and geostatisticaltools were used. Data of Chengdu plain soil in 2005 were adopt to simulate the spatial distribution ofsoil heavy metals and the risk probability of pollution occurrence in Chengdu plain under macro-scale,and analyzed the reason that caused industry pollution by soil heavy metal Cd,Cr, Cu,Pb,Zn, As and Hgin spatial dimension. Furthermore, this paper discussed the main influencing factors of soil heavy metals,such as municipal solid waste, distances to the downtown, roads and rivers,and based on the influenceof social economy factors, the economic losses put forward.The result showed that as follows:.(1) From the overall characteristic analyses of soil heavy metals pollution degrees in Chengdu plain,the results showed that all the detectable rates of cadmium, chromium, copper, zinc, arsenic, mercurywere 100ï¼…, the exceeding limit rates were 2.11ï¼…,0.70ï¼…,21.59ï¼…,1.33ï¼…,4.48ï¼…,4.48ï¼…, respectively.Thelead content had not Surpassed environmental quality standard for soils.(2) The soil heavy metal pollution of spatial simulation results in these regions showed that all thepollution tendency in the overall presents east, north were higher than the west, the south except Ascontent, which were mainly correlated with the distribution of pollution sources.(3) The influencing factors analyses indicated that, the existence of pollution sources mainly causedby the spatial variances of the economy factors especially the Area place factors. The social economyfactors affected the space differences of different heavy metals were more complicated. Discussed thedistribution characteristics of heavy metals under different industrial arrangements, the distribution ofCu,Pb,Hg contents had extremely remarkable relations with industrial distribution under different scales.the more the industry especially the specially appointed contaminate developed, the higher the heavymetal contents, but the variances of soil Cd,Cr,Zn,As contents had less differences under the industrialand enterprise layout. Furthermore, discussed the influences of municipal solid waste to the heavy metalcontents, finally results indicated that the drainage of municipal solid waste had a certain relations with the mean values of Cd,Cr,Hg in general, but the heavy metal contents of Cu, Pb, Zn were not obvious.Combined with data of the five main districts in Chengdu, the Cd, Cr, Hg contents in Qingyang andWuhou district which had high waste drainages was higher than those of Qingbaijiang and Longquanyidistricts. The Changes of heavy metal contents in different distances outside the downtown indicatedthat the difference distances to the downtown has no direct relation with the changes of theCd,Cr,Cu,Zn,As,Hg contents, but assumed the remarkable indexes correlation relations with the soilPb content within 4 km range outside the city center. Analyzed the main highway such as Chengpeng,Cheng-Wenqiong, Chengle, all the elements levels reached safety levels except the average contents ofPb and Cu near the city highways section which surpassed the environment quality standard for soils,but would not remove the pollution possibility caused by the soil in the future. In study area, thedifferences among the main around highway section, Chengpeng, Cheng-Wenqiong, Chengle and thesoil contents of Cr,Cu,Pb was remarkablely, but the differences of Cd, Zn were not obvious. Influencedby the river transporting changings, soil heavy metal present different distributing characteristics indifferent rivers, one of the most reasons of the pollution was caused by the waste water dischargedwhich come from the caustic soda, mercurate thing, paint, accumulator cell factories. In a certaindegrees, water loss and soil erosion was also lead to soil heavy metals pollutions between regions inChengdu Plain.The heavy metal characteristic research under the different land utilization indicated that,the fertilizer and management level to the vegetables'and paddy field crops was the main reason causingdifferent heavy metal accumulation.(4) Economy loses amounts estimating result indicated that,area for economic loss was282.93hm~2 and was 2.67ï¼…in the whole study area.From four aspects,the economic loss for heavymetals pollution in 2005 was 339,520,0 RMB.(5) In view of the heavy metal pollution present situation in Chengdu plain,measures should betaken including the economy, the law, the administration,the technical method,to achieve comprehensivetreatment contaminates purposes.