Numerical Simulation Of Groundwater Flow In Dalatulu Well Field In Ordos Energy Base

There are plenty of energy and mineral resources in Ordos energy base of Inner mongolia, such as coal, natural gas and oil, Which make it become the significant energy industry base. In order to provide abundant water resource, it has been found that Dalatulu area is rich in groundwater resource after preliminary hydrogeologic exploration, where we plan to build well field so as to provide reserved water resource for economical development of Inner Mongolia.Within the study area of 2256km~2 and the detailed investigation area of 775 km~2, the main aquifer is Cretaceous Formation which is very thick with the study depth of 345m, and we mainly study the shallow and the upper cycle of the groundwater system. The simulation model was divided into two aquifers in the vertical profile.This dissertation set up the hydrogeologic conceptual model and groundwater numerical model using the software Visual Modflow by analyzing the hydrologeological condition of the study area. The model is proved to be able to analyze water budget, evaluate water resource and predict the groundwater table by identifying hydrologic parameters, fitting flow field and hydrograph, as well as matching the calculated results to actual budget.The budget result demonstrates that the total recharge rate of the groundwater system was 4316.11×10~4m~3, the total discharge rate was 3902.27×10~4m~3, the difference rate between the recharge and discharge 413.83×10~4m~3 during the simulation time of the study area.In this dissertation we evaluate the recharge resource of the interest region, the budget table concluded the average groundwater recharge rate of the research area was 4015.50×10~4m~3/a, The side inflow was the main recharge source, the rate of which reached to 2170.60×10~4m~3/a, and took up 54.06% ; the following recharge source was rainfall infiltration, the rate of it was 1844.91×10~4m~3/a, taking up around 45.94% of the total recharge resource rate.We designed three different exploration methods of the well field and established the prediction numerical model of Dalatulu well field. The tendency of groundwater table has been predicted under the condition of 108000 m~3/d and 102000 m~3/d for 30 years in three designed programs separately. Then choosing the optimum method by analyzing the drawdown and falling range of the well field after 30 years’exploration. According to the results, under the optimum program the exploitable resources will be 4911.16×10~4m~3/a. And we can conclude that the exploitation was reasonable, and the water support can be ensured.