The Study Of Groundwater Functional Evaluation And Controling Of Tianjin

With the acceleration of urban construction,the economic scale expands unceasingly,the water demand in Tianjin is increasing year by year,but the water resources of Tianjin are very scarce.Groundwater,as the main source of water supply in Tianjin,its excessive mining caused many environmental problems,such as serious land subsidence,seawater intrusion,the deteriorating of water quality and many other environmental geological problems.The main reason is that the groundwater has been put into practice in China for a long time to product management mode,but it's hard to measure the groundwater production directly.Also,it is not convenient to regulate assessment and the actual operation.Its management mode also has a lot of defects,in order to make up for the lack of this kind of management mode,this research put the according results of the groundwater function evaluation of Tianjin,and set up the critical water table to manage groundwater resources of the new management mode.The main research contents and results of this paper are as follows:(1)In order to implementation the groundwater's rational develop and utilize,scientific management and effective protection of Tianjin,this paper first analyses the situation of development and utilization of groundwater in Tianjin,according to the distribution characteristics,type characteristics,hydrogeology conditions and the exploitation and utilization status of the study area,we put forward the corresponding evaluation index,and use the analytic hierarchy process and the coefficient of variation method of subjective and objective evaluation in the evaluation to gets synthesis weights.According to the relevant evaluation indexes that are put forward,we calculate the corresponding composite index.According to the composite index of evaluation criteria standard,we composite the groundwater's resources function,the ecological environment function and the geological environment function in Tianjin was respectively evaluated,and it concluds the comprehensive evaluation results of groundwater in Tianjin.(2)Through evaluate the groundwater in Tianjin,we got the conclusion: In the aspect of resources function,the level of resources function evaluation of Ji country,Baodi district and Wuqing district are good,these three area's groundwater resource functions are strong,they are suitable for mining.The level of resources function evaluation of Hangu district,Jinghai country and Dagang district are weak,we should look for new water resource instead.In the aspect of ecological function,the level of ecological function evaluation of Dagang district and Tanggu district are good,we should maintain it.The level ecological function evaluation of Ji country is terrible,we should stop the ecological destruction behavior to strengthen the ecological restoration.In the aspect of geological environment function,the level of geological function evaluation of Dagang district and Wuqing district are good,we should maintain it.The level of geological function evaluation of Baodi district and Dongli district are terrible,we should stop mining,formulate measures to repair and increase the protection of geological environment,at the same time,we should monitor the change of geological environment and prepare warning(3)According to the groundwater function evaluation results and the groundwater history observation data of Tianjin,we build the model,calculate the groundwater critical water level of Tianjin by using entropy calculation method,and combined with the water condition of Tianjin,we obtain the groundwater's management solution of Tianjin.