Environmental Risk Evaluation Of Shallow Ground Water And Its Spatial Auto-correlation In Lower Reach Of Liaohe River Plain

As the economies are in the fast development, disasters occur more frequently.Evaluation, monitoring, and early warning of disaster risks are an important way to reduce thelosses caused by the disasters. So it is one of the key topics in the current disaster research. Asa major source of water in northern China, groundwater provides resource and ecological andgeo-environmental functions. However, groundwater systems in northern China are beingthreatened by high population density, rapid urbanization and industrialization. Generallyspeaking, groundwater has been damaged to different degrees, which resulted in the decreaseor complete loss of the functions of groundwater systems. So the research of groundwaterenvironmental risk has great practical significance.In this article, the lower reach of Liaohe River Plain was chosen as a study area, and theshallow ground-water system was taken as a research object. The study area contains a largeQuaternary groundwater system with characteristics typical of northern China. Socialeconomic data and water environmental information of the Liaohe River Plain in2012wereused in the study. Although many studies on groundwater have been conducted, few theoriesof groundwater environmental risk and methods of protection were developed at thegroundwater system scale. Drawing lessons from modern hazard and environmental risktheories and methods, based on the definitions of groundwater environmental risks, we builtan evaluation index system and an evaluation model for groundwater environmental risksfrom the aspects such as vulnerability, functionality, stress and adaptability. Using GIS spatialanalysis method to evaluate the groundwater environmental risks in this region, we carried outspatial auto-correlation analysis.The results show that:63.12%of the whole groundwater environment is facing amid-level risk. In detail, the areas with extreme high risk accounts for6.79%, the areas withhigh risk18.96%, the areas with moderate risk37.37%, the area s with light risk21.98%,and the areas with slight risk14.90%.Most high risk areas are mainly in the northeast ofXinmin City, Dengta City, west of Liaozhong County, parts of Heishan County and southeastof Linghai City. The risk of the study area shows a relatively high degree of positivecorrelation. The high correlation areas are mainly distributed in mid-east and mid-west of thehigh-risk areas and the northeast and southeast of low-risk areas. Uncertainty evaluation is animportant part of the environmental risk analysis. But due to limited data, we didn’t consider the indexes of randomness and fuzziness, which to a certain extent affects the scientific natureand reliability of the evaluation results. With constant improvement on the informationsources, more studies will be done to include uncertainty index of groundwater environmentalrisk evaluation. The specific purpose of this study is to investigate measures to protect thethree functions of the groundwater systems based on groundwater system risk evaluation.This study is of great significance to the enrichment of groundwater environmental risktheories and methods, and it also helps with making scientific decisions for the protection ofthe groundwater system of the lower reach of Liao River Plain and similar areas.