Evaluation And Hotspots Analysis Of Shallow Groundwater Contamination Risk In The Lower Reach Of The Liaohe River Plain

Because of their stable water supply volume,good water quality,and comparatively strong regulation and storage capacity,groundwater resources have become one of the main water supply sources for many uses,such as urban and rural residents' life needs,mining,industrial production,and agricultural irrigation.The lower reach of the Liaohe River Plain is located in the core region of the central and southern industrial base of Liaoning,where groundwater resources are developed and utilized extensively and the groundwater supply accounts for 65%of the total supply.With the rapid development of urbanization and rapid growth of the population,the balance between consumption and supply of groundwater is becoming untenable.Intense human activities have had a great influence on the groundwater environment.With large amounts of external contaminants flowing into aquifers,the quality of groundwater has decreased gradually,which is a severe threat to the environmental quality and functional value of groundwater.It is obvious that the issue of groundwater contamination is becoming increasingly prominent.Evaluation of groundwater contamination risk has been carried out on the basis of groundwater vulnerability evaluation.Is not only an important component of groundwater environmental risk assessment,but also a significant link of prevention and control of groundwater contamination.In view of this problem,the lower reach of the Liaohe River Plain was selected as the study area of this research,in which an evaluation of the contamination risk of shallow groundwater was carried out to identify the areas at high risk for shallow groundwater contamination.It has great significance for promoting the protection and sustainable utilization of groundwater resources.Remote sensing(RS)and geographic information system(GIS)is the product of the combination of information technology and modern geography,which provide strong support for research of groundwater system.Based on theory of disaster,we have built an evaluation index system and a contamination index model for groundwater contamination risks from intrinsic vulnerability,external stresses and functional value.We used the technology of data acquisition and spatial analysis by RS and GIS to assess the value of groundwater contamination risks in this region.In discussing the contamination risk and its mechanism,we can obtain spatial distribution of hotspots by calculating G index at the same time.Finally,gravity and standard deviation ellipse tool is introduced to the groundwater contamination risk assessment,analyzed the contamination risk overall direction and trend of hotspots.The results reflect the spatial distribution and formation mechanism of groundwater contamination risk in the study areas.It can provide relative reference for land use planning and protection of groundwater resources in the lower reach of Liaohe River Plain.