Study On Hydrogeological Characteristics And Water Yield Prediction Of Diatomite Area In Dongshan Village,Dunhua City

The Dongshan diatomite field is located in the basin of the Cenozoic rift basin controlled by the Dunhua-Mishan fault zone.The basin is the Mesozoic Mesozoic strata in the Neogene?N₁t?.The diatomite deposits are mainly found in the strata formation?N₁t?,and the stratigraphic consolidation degree is poor,the geological and hydrogeological conditions are complex,the water richness is better,the mining layer is difficult to be calculated accurately and reasonably and the water demand is expected to be the future mine Safe mining,drainage program design to provide theoretical basis for the guidance of similar diatomite mining has important scientific significance.Based on the theories of hydrogeology,engineering geology and groundwater dynamics,this paper comprehensively applied the technical methods such as hydrogeological investigation,pumping test and indoor experiment,and adopted the method of "big well","water balance" and "numerical simulation" And other methods,means to predict Dongshan diatomite mine mine water inflow.The results of the study are as follows:Combined with the hydrogeological characteristics of the study area,the vertical distribution of the water layer and the ore layer is divided into the Qh^al loose rock aquifer + Qp1 j,Qp3nand N₁t10+8basalt aquifer + N₁t7?K₂ Mine layer?aquifer + N₁t6+4 basalt aquifer + N₁t³ sandstone aquifer + N₁t2?K₁ Mine layer?aquifer + N₁t1 sandstone conglomerate aquifer combination structure.Based on the geological model and hydrogeological conceptual model,a mathematical model which can describe and reflect the characteristics of groundwater flow in the study area is established.Then,the model of MODFLOW in GMS is established.Based on the geological model and hydrogeological concept model,The model is used to identify and correct the model.The results show that the model can be used to identify and correct the model with J03 and JG03 pumping test data.Finally,the model is used to identify and correct the model.The actual water level observations are in good agreement with the calculated water level values,indicating that the simulated parameters,boundary conditions and source and sink items are reasonable,and the model is reliable and can be used for mine water demand forecast.Based on the identified and validated model,the Well?pumping well?module in GMS was used to set up six pumping wells in the mining area to predict the maximum water inflow in the rainy season.7800m3/d in the rainy season was predicted by the "well system" and "water balance method".The calculated gushing water rates were 8044m3/d and 7714m3/d,respectively,and the difference between the maximum gushing water predicted by the model was 3.13% and 1.10%,respectively.The results obtained by the three methods were close to each other,and the results were further validated Reliability of mathematical models.