Study On Double Control Of Groundwater Level And Quantity In Taiyuan Basin

Located between Luliang and Taihang Mountains,the Taiyuan Basin straddles the cities of Taiyuan,Luliang and Jinzhong.It has the best land resources in Shanxi province,is an important food production base,and is the economic,political and cultural center of the province.However,since the 1980s,with the rapid development of economic and social life,the groundwater in the basin has been exploited indiscriminately,with three large water funnels and five overmining zones,and a series of environmental problems have arisen.In order to alleviate the contradiction between supply and demand,protect groundwater resources,clarify the factors affecting groundwater change in Taiyuan Basin,formulate suitable exploitation plan and double control index of water level and volume,it is of great significance to the sustainable scientific exploitation of groundwater.In this thesis,the multivariate linear regression model is established that rainfall and mining volume are important factors affecting groundwater level in Taiyuan Basin,which provides a basis for controlling water level by controlling mining volume.In this study,three-dimensional geological model,hydrogeological conceptual model and numerical simulation model of Taiyuan Basin are established respectively.The model was identified and validated using PEST parametric method and trial-validation method.After validation,water equilibrium analysis was performed on all source sink data.The results showed that Taiyuan basin averaged 6.8 × 108 m3/a from 2001 to 2019,with an average annual recharge of 8 × 108 m3/a,a negative overall balance of-1.2 × 108 m3/a.Side runoff recharge and rainfall infiltration recharge are the main sources of groundwater recharge,accounting for 85%of total recharge.Artificial mining is the main discharge route,accounting for 86%of total excretion.Using the water balance method,the recoverable amount of groundwater in Taiyuan basin is 5.6 × 108m3/a by water equilibrium method.According to the recoverable amount,a mining plan that conforms to the current mining situation of Taiyuan Basin was formulated.The prediction model was introduced to simulate the change of water level in the study area under the three scenarios of high and low water in five years.After the analysis of water level indicators,the control index of the mining amount in high and low water years was finally selected as 3.9 × 108m 3/a.The control index of mining volume in dry year is 3.4 × 108m 3/a.According to the selected control index of the exploitation amount,during the prediction period,the shallow groundwater level and the middle and deep groundwater level in Taiyuan basin are on the rise.The study area has achieved the balance between mining and replenishment on the whole.Then,the feasibility analysis of groundwater pressure exploitation in Taiyuan Basin has been carried out to ensure the rationality of the scheme implementation.Finally,the mining quantity control index and the water level control index of each county and district are determined,the water level index is refined,and the refined index can be used as the basis for the water level and water level double control management by relevant departments.