Spatial Variation And Risk Assessment Of Heavy Metals In The Soil Of Delta Region Changjiang River

With the Changjiang River Delta to speed up the process of urbanization, heavy metal pollution has received much attention. Input and output of heavy metals to do quantitative analysis, can accurately understand the system and the balance of heavy metal pollution to control the accumulation of heavy metals in the trend of pollution on the ecological risk assessment of sustainable agricultural development and provide an important basis.Based on the Changjiang River Delta, including Shanghai, Jiangsu Province, Nanjing, Yangzhou, Zhenjiang, Changzhou, Wuxi, Suzhou, Taizhou, Nantong, Zhejiang Province, Hangzhou, Huzhou, Jiaxing, Shaoxing, Ningbo, Taizhou and Zhoushan cities in 16 surface soil seven heavy metals in soil and deep quantitative analysis, using GIS software to draw a soil geochemical maps; combined with chemical content of deep soil and shallow map of the chemical content of heavy metals to do quantitative analysis; and raised by Swedish scientists Hakanson Ecological Risk Assessment method of soil heavy metals in the degree of potential ecological risk assessment, to the soil for future use of the Yangtze River Delta region, environmental management and development planning to provide some scientific basis, the main conclusions are as follows:(1) Changjiang River Delta region through the surface and deep relationship of soil geochemical and geochemical characteristics of the distribution, in the light of previous studies based on the results, further defined soil geochemical reference value of the basic concepts, and according to academics out soil geochemical methods to obtain reference values calculated seven heavy metals in the Yangtze River Delta soil geochemical reference value. Assessment of the Yangtze River Delta provides data to support the soil.(2) On the Yangtze River Delta multi-objective regional geochemical survey data, and overlay of soil types, using GIS software, using Kring universal kriging grid method for the eight kinds of heavy metals in surface soil, deep soil geochemical Figure 14 Zhang, comparative analysis of the Changjiang River Delta pollution trends in surface and deep, can be intuitive to some extent reflected the situation of soil pollution Yangtze River Delta, Yangtze River Delta to carry out basic geological studies, land use, mineral resource potential assessment, environmental protection system is based on maps provided.(3) On the Changjiang River Delta surface and deep soil pollution status of the overall evaluation, that contaminated soil along the river, Yangzhou, Nanjing, Changzhou, Wuxi, Suzhou, Shanghai, Hangzhou, Shaoxing, Ningbo and other cities and the surrounding areas of soil contamination , Huzhou - Suzhou acidification is a major regional polluted area.(4) In this paper, the Swedish scientists Lars Hakan son made of the potential ecological risk evaluation carried out on seven soil heavy metals in the degree of potential ecological risk assessment. And trends in the evolution to a single factor maps and map pollution levels; one, single factor evaluation results show that mercury, lead, cadmium and other elements in areas far exceeded mainly in Shanghai, Nanjing, Zhejiang and other developed urban centers, results show that both the city acceleration of the process, and land use change on soil environmental impact; comprehensive ecological risk map shows the area of the pollution intensity level and above accounted for about 80%, and appeared in larger urban centers of local pollution, prevention of soil pollution posed new challenges, therefore, necessary to the construction site on the Yangtze River Delta region and the geochemistry of agricultural land for content monitoring, agriculture, human settlement and other security assessment.