Prediction Of Groundwater Environmental Impact In Tongnan District, Chongqing

As a non-renewable resource on which the life on earth depends at present,water resources are extremely important living conditions for human society and even the entire ecosystem.In the whole water resources system,groundwater resources,as one of its key components,have already played a very important role in human society.At the end of the 20 th century,with the expansion of human activities,population explosion,social progress,lack of surface water resources and pollution are becoming more and more serious,so people began to rely on relatively clean groundwater due to underground burial.In our country,underground fresh water resources account for about one third of the total water resources and are one of the important sources of water for residents' living and social production development.At present,many urban areas in our country use underground water as their production and living water.It is precisely because of the buried characteristics of groundwater that once polluted,it is difficult to control or restore,and will directly affect the living water of human beings and the progress and development of society.Therefore,how to solve this problem is extremely urgent.In this study,the proposed site of Wanlilai Chemical Plant in Tongnan District of Chongqing City is taken as the research object.On the basis of groundwater numerical simulation software(GMS),the groundwater environmental pollution around the plant area which may be caused by Wanlilai Chemical Plant under working conditions is evaluated and predicted.On the basis of sorting out a large amount of hydrogeological data,investigating the present situation of groundwater quality and monitoring the groundwater environment in Tongnan district,a reasonable evaluation of the present situation of groundwater quality in this area has been made.At the same time,the aquifer type and groundwater characteristics of the study area are analyzed,and the study area is generalized into a heterogeneous,anisotropic and two-dimensional steady flow groundwater model.A hydrogeological conceptual model of the study area is established to simulate the groundwater flow model in the study area.According to the analysis of the fitting results with the measured flow field,the model can be used to represent the actual groundwater flow state in the study area.On this basis,through the analysis of the pollution sources in the factory area,the COD with the highest content in the production process of the chemical plant is selected as the characteristic pollution factor for prediction.Assuming that the sewage pool in the chemical plant leaks due to sewage corrosion and other reasons,and the anti-seepage measures are partially ineffective,the COD index in the groundwater in the study area is simulated and predicted.The analysis of the groundwater pollution prediction results in the study area proves that the COD pollution halo pattern is obvious with the passage of time,its range is continuously increasing and finally tends to be stable,and the maximum pollution concentration value of pollutants also tends to increase first and then to be stable with time.According to the pollution prediction results,the source control and protection measures and zoning control and protection measures are proposed for the plant area.This study provides a method reference and theoretical basis for the prediction of the environmental impact of chemical plant relocation and proposed construction on groundwater in the future,and has important practical significance.