Modeling And Analysis Of Groundwater Flow Model In Plain Area

Daxing District lies in the south of Beijing city and encompasses 1030.6 square kilometers. The terrain in southeast is lower than in northwest. The elevation is between 15 and 45 meter. The slope is one of one thousand two hundred and fiftieth. Daxing District is part of the alluvial plain of Yongding River.With the development of economy, the requirement of groundwater in Daxing district increases rapidly in recent years, the groundwater is exploited excessively and groundwater table fall down continually. This can induce some bad results. But this is extremely common in the arid and semi-arid area. In this situation, for sustainable economical development and sustainable use of water, it is necessary to analyze the movement of groundwater exactly and appraise the local groundwater resources scientifically.In this paper, Daxing district's hydrogeology condition is simplified,and a numerical modeling is applied to study on the groundwater of Daxing district. The numerical modeling includes two aspects, one is to build the hydrogeology conceptual model to process the sources/sinks, and the other is to calibrate the model constructed.The hydrogeology conceptual model is build with the conceptual model method in GMS software, and predict-adjust method is used to calibrate the model. Then the model is run to simulate the dynamic change of groundwater level, and primary influencing factor of the change of groundwater level is analyzed.The influx to Daxing district is primarily through recharge due to rainfall,so assign an accurate recharge rate is very important. This paper considered the nonuniformity of precipitation and the validity of recharge due to rainfall when give the recharge rate. The analysis to calculated result indicates that, the influx to Daxing district is primarily through recharge due to rainfall,it occupies 67.69% of the total recharge volume. The second recharge is due to irrigating recharge, it occupies 23.26% of the total recharge volume. Manual exploitation is almost the only way of discharge,it occupies 99.62% of the total discharge volume ,and the agriculture irritation occupies the biggest share of exploitation, it occupies 96% of the manual exploitation volume . The main factor of the groundwater table change is recharge and exploitation, the precipitation and the exploitation which cause the groundwater regime changing dynamically.