Assessment of Potential Ecological Hazard of Heavy Metals in Farmland Based on GIS

This paper includes the analysis of total content of Cd element of 102 samples in the surface soil of farmland around the slag field. We evaluated the contamination of Cd of each samples and the space distribution with the potential ecological risk index method based on ArcGIS soft. The results showed that: average of potential ecological risk index of Cd is 241.4, Moderate ecological risk area accounted for 2.7% of the study area, strong ecological risk area of the region accounted for 30.1% of the study area, 22.2% of the study area had the considerable ecological risk, and the rest 39% of the study area had the extremely strong ecological risk. Mineral resources provides important energy to national economy and our daily life, but with the development and utilization of mineral resources significantly increasing, the harm to the environment of heavy metals in smelting wastes gets more and more attention. Cd is a kind of hazardous element, if we intake cadmium-containing substances for a long while, we may Suffer from "Itai-Itai Disease" and other diseases or even die. There are lots of international and domestic researches about the ecological hazards of heavy metals on environment in the surrounding area of slag field in recent years. Pazi I has evaluated heavy metals in surface sediments of Candarli Gulf with the potential ecological risk index([1]). Zhao Xinna has done the research of the ecological pollution in the part of soil in Shanghai([2]). Wu Di has evaluated the potential ecological risk in the sediment of Wujiang River([3]). This paper takes the Cd element in the farmland near slag field as example, and evaluates the pollution caused by Cd element with the potential ecological risk index.