The Early Warning And Remediation Measures For Heavy Metal Ecological Risk Assessment In Dabaoshan Mining Area

The ecological restoration of metal mines is the key to the green development of the mining area's economy and is of great significance to the realization of ecological civilization construction.However,with the continuous progress of ecological restoration,there are many problems.In view of the lack of preliminary data in the current metal mining areas,ecological restoration is often "headache" and "foot pain".The root cause of the problem is not found,and ecological restoration is systematically carried out from the source and targeted.It is particularly important to scientifically,accurately,quickly and conveniently grasp the real-time ecological risk status of metal mining areas and make predictable decisions in time,establish and improve the ecological risk early warning system of metal mines,and carry out targeted ecological restoration at the same time.This study combines metal mine mining activities and watershed soil erosion and other complex influencing factors to construct a comprehensive early warning simple model based on ecological indicators;following the concept of material and energy sources and sinks,according to the basin scale,it reveals the internal material migration and transformation as well as the impact.The impact of the entire watershed is analyzed,and its restoration resistance and priority divisions are analyzed.The classification divisions propose restoration priorities and countermeasures,in order to provide a scientific basis for the restoration of the restoration project on the time and space scale,so as to achieve the purpose of scientific governance.The research conclusions are as follows:(1)The four heavy metals exceed the standard in different degrees in the surface soil of the study area,and the exceeding rate of Zn reaches 65.22%;the spatial distribution pattern of different heavy metals is basically the same,and generally it shows a higher trend of heavy metal content around mining activity area;The research results are as follows through comparing the Pn,Igeo and RI:The results of heavy metal pollution assessment in the study area are consistent,which are basically above moderate pollution.Through correlation analysis and principal component analysis,the source of heavy metals in the soil of the study area is further understood,and it is speculated that Zn and Cu are mainly affected by mining activities,Cd is affected by mining activities and traffic factors,and Pb is mainly affected by mining activities The effect of acid water and acid irrigation wastewater discharged into the downstream river;Erianthus arundinaceus has the advantages of enrichment on four kinds of heavy metals,and has good absorption accumulation and transport capacity for Zn and Cd,which can be used as remediation plant for Cd and Zn polluted soil.(2)The evaluation results of the comprehensive early warning model based on the ecological indicators show that:the comprehensive ecological risk index of the study area is between 0.6-8,with an average of 3.68,which belongs to the light alarm level;the heavy alarm areas of the two early warning models are distributed around the mining activity areas,showing a reverse distribution between the severity of the alarm and the distance from the mining activity areas,and showing heavy alarm and medium alarm in turn The spatial distribution characteristics of light warning,early warning and no warning;the comprehensive early warning model based on ecological index and the comparative model based on ecological risk early warning index have strong similarity in space and quantity,so the model is scientific and practical,which can represent the early warning situation of the whole basin and provide method reference for the research of similar basins.(3)Based on the minimum resistance model(MCR),this paper analyzes the resistance and priority zoning of ecological restoration in the mining area watershed,and puts forward the key points and Countermeasures of classification and zoning management.The results show that the resistance values of different evaluation indexes are larger in the southeast and smaller in the northwest,and the nearer the mining area is,the higher the priority of ecological restoration is;the study area is divided into five priority areas,and the priority of restoration is in the order of area ?>area ?>area ?>area ?>area V.area ? is the concentration area of mining activities,and low vegetation coverage,high heavy metal content and serious land damage are the main factors The main measures include the establishment of sewage treatment plant,plant stabilization and plant extraction;the core of area ?,? and ? is soil treatment,and the main measures are plant barrier.