GROUNDWATER POLLUTION DYNAMIC RISK ASSESSMENT BASED ON NUMERICAL SIMULATION AND RISK SCREENING
Since the traditional groundwater risk assessment of contaminated sites ignored the risk of pollution spreading risk,a groundwater contaminated site and its surroundings in Hunan were selected as the research area for groundwater pollution dynamic risk assessment and trend prediction.A combination of quantitative and qualitative methods was used to establish a dynamic assessment method based on numerical simulation and risk screening through index screening and determination.The simulation prediction shows that the pollutants in the soil and groundwater of the site gradually diffuse downstream over time.The concentration of Cr(Ⅵ)in groundwater reaches a maximum of 1239.5 mg/L on the 38th day.Pollutants migrate to the river on the 585 day,and the groundwater pollution plume reaches its maximum on the 917th day.The total groundwater pollution risk scores of the site calculated by the two methods are 76.2 and 72.4,both belong to high risks,indicating that qualitative analysis of migration in the vadose zone and the water-saturated zone may tend to be conservative compared to quantitative analysis.The dynamic risk assessment results show that the site is always at high-risk throughout its lifetime,and the groundwater pollution risk first rises and then declines,reaching the highest risk of 95.2 points from the 500th day to the 700th day.It is suggested that groundwater risk control or restoration should be carried out to avoid greater risk.
NETL
NSTL
万方数据
