Ecological Risk Evaluation Of Heavy Metal Pollution In The Reclamation Soil Of Coal-based Villages

There are a large number of villages having been or are about to be abandoned in the Loess Plateau because of coal exploration and related resources-occupied problems. Carrying out the village reclamation work is becoming an useful way of supplying farmland and improving environment. The content of heavy mental is an vital factor of evaluating the soil quality and it is of great significance to the monitor and evaluation of land quality in reclaimed villages. Making clear of the situation of heavy metal in reclaimed soil is important to enhance the quality of arable land and carry out the reclamation measures.The paper selected Xigao countryside as the research area,conducted the ecologic risk evaluation of heavy mental content through the potential ecological risk index methodology.And aimed to demonstrate the degree of heavy metal pollution in the soil and its spatial distribution rules comprehensively,thus providing some reference for reclamation measures scientifically.The research firstly collected and processed the data of the content of soil heavy metal pollution of the research area, and conducted the analysis of the current heavy metal content from diverse perspectives such as different depths of layers and different elements. Then, the research conducted the comprehensive evaluation of heavy metal content of the soil through the potential ecological risk index methodology, and demonstrated the degree of heavy metal pollution in the soil and its spatial distribution rules comprehensively. Ultimately, the sources of soil pollution and impact factors of ecologic risk evaluation were analyzed and put forward some measures could be taken in the application of village reclamation works.Through the above researches, this study obtained the following conclusions:1,The integrated soil heavy metals pollution and potential ecological of Xi Gao countryside is in the moderate risk level. 2, From the perspective of the single element, the degree of contamination and potential ecological risk level of Hg is at a high level, thus in the process of village reclamation,the corresponding measures of reducing the content of Hg should be taken. 3, the areas of moderate ecological risk level are mainly located in the middle and southeast of the village and the residential area which were built after the 1990 s due to the impact of coal mining and industrial activities. The farmland and the residential area which were built 50 years ago is less polluted.4,Soil of 0 ~ 20 cm layer is affected by human activities and its comprehensive pollution level and ecological risk level is significantly higher than the 20 ~ 40 cm soil, and area which is in the moderate ecological risk level is widely distributed. 5, This paper uses the potential ecological risk index to evaluate the content of heavy mental,which can reflect the comprehensive quality reclamation of heavy metals in contaminated soils and the ecological level of risk. It provides the basis for improving the quality of arable land after reclamation and can take reasonable measures.