Abstract:Mining area is a high incidence area of heavy metal pollution in agricultural land. Scientific evaluation of heavy metal pollution risk in mining area is very important for human health and ecological environment. In view of the shortcomings of the current fuzzy comprehensive evaluation method in the selection of membership function and determination of weight, starting from the relationship between heavy metal concentration and exposure hazards, logistic function distribution is selected to replace the commonly used trapezoidal distribution as the membership function; Considering that the soil pollution risk control standard of agricultural land is related to soil pH value, the pH variation coefficient is introduced, and a combined weight determination method combining pH variation coefficient method and pollution multiple method is constructed. The research results of typical mining areas in Daye City show that the average contents of heavy metal elements As, Cd, Cu and Zn in agricultural land in the mining area are higher than the soil background value in Hubei Province, which are 3.28, 4.35, 3.71 and 1.86 times of the background value respectively. As, Cd and Cu are the main pollutants; The improved fuzzy comprehensive evaluation results show that among the 21 sampling points of agricultural land in the mining area, 19 belong to mild pollution and 2 belong to severe pollution; The heavy metal pollution rate of agricultural land in this area is 100%. Safe utilization measures should be taken to strengthen the detection of soil environment and the collaborative detection of agricultural products. Compared with the current fuzzy comprehensive evaluation method, the improved fuzzy comprehensive evaluation improves the selection of membership function and determination of weight, is more sensitive in evaluation classification, considers more possible risks, and provides a reference scheme for reasonable evaluation of heavy metal pollution risk in agricultural land.

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