Case Study On Risk Prevention Area Of Groundwater In The Midst Of Hexi Corridor Region

The groundwater pollution risking zone is an important basis for protection of groundwater resources.Groundwater contamination in the domestic situation is serious,especially heavy metal pollution because heavy metals are difficult to be degraded in the water and dangerous to human health.In the midst of Hexi Corridor region belonging to the arid area,the resistant ability to external interference of groundwater is weak which means it is easily contaminated.An empirical study of groundwater environmental risk prevention in the Hexi Corridor region,the protection of arid zone groundwater is of great significance.This article discusses the the establishment of groundwater risk prevention area,risk zoning,risk management and emergency response system.Briefly introduced the hydrogeological characteristics of Zhangye basin.Using the survey datas study on a chromium salt company in the Zhangye Basin groundwater environment.Including the following aspects:(1)According to the theory of environmental risk zoning and underground pollution risk characteristics,sum up the groundwater environmental risk prevention zone of influence factors.The main influence factors include groundwater vulnerability,external pollution sources,the environmental quality status of ground water,demographic factors and the sensitivity of target.(2)In the light of groundwater environment quality status,the pollution of sources present situation as well as the vadose zone pollution status go to investigate,analysis of heavy metal pollution status,access to Cr(VI)pollution background value.(3)Risk prevention zone is determined by the source of risk of accidents,select the amount of leakage under the maximum credible accident,According to the region’s groundwater quality function to determine the biological damage threshold.forecasting The scope of groundwater pollution about risk prevention area.(4)On the base of risk prevention area,using the risk quantification model,establish a system of indicators by the characteristics of the sources of risk and vulnerability risks receptor characteristics.Index system consists of the target layer,rule layer,layer 2 and indicators layer.Using the analytic hierarchy process to evaluate the area of each unit of risk prevention area.The value of the comprehensive evaluation is divided into high risk areas,the risk areas and low risk areas,very low-risk areas.(5)The factory is divided into 15 units,according to the risk assessment results,the cell is divided into a high risk area,risk zone,low risk area and very low risk zone.The 8 units belong to the high risk area,5 units belong to the risk area,lunit belongs to low risk areas,1 units belonging to a very low risk area.The area with high risk is needed to focus on protection,on the basis of risk unit features different seepage controling scheme and the structure,provide the basis for prevention and treatment of groundwater pollution.