A Study Of Numerical Model Of Groundwater Flow In Houtao Plain Of Neimenggu

Houtao plain is the base of grain, industry and dairy of the country and autonomous regions. With the unreasonable using of water resources, hydrogeology problem is becoming serious and restrict seriously the development of regional economy. So it is urgently time to investigate the hydrogeology conditions of the Houtao plain and to evaluation of groundwater resources again.Now, the exploration of groundwater resources in Houtao plain is just in mapsheet and administrative regions, ignoring the integrity of groundwater system, so it is hard to make an objective assessment of the water resources of the whole system. The purpose of this study is to establish a large-scale regional model for analyzing the groundwater resources of the whole plain. Establishing the numerical simulation model of groundwater in Houtao plain and evaluating of groundwater resources can grasp the distribution of groundwater resources, water quality and water quantity in the strategic height.This paper use GMS software. The groundwater structure model (unconfined aquifer、shallow confined aquifer and deep confined aquifer) is established on the existing drilling and profile data by interpolation. Then establishing the conceptual model of groundwater flow by analyzing aquifer structure, boundary conditions, characteristics of groundwater flow, groundwater source and sink terms. Make the conceptual model and the structure model combined to establish the groundwater numerical model of the Houtao plain.The use of the numerical model is to do the evaluation of groundwater recharge resources. The groundwater recharge resources is 27.15×108m3/a (not include the flow between layers), irrigation infiltration is 12.64×108m3/a, which is about 46.54% of total recharge; canal seepage is 7.60×108m3/a, which is about 27.99% of total recharge, the recharge modulus on average is 16.23×104m3/km2·a. Then do the available groundwater resources evaluation by the method of available coefficient, the available groundwater resources is 16.14×108m3/a, the available modulus on average is 9.67×104m3/km2·a. The main discharge is evaporation, followed by the drain.Analyze the change of balance according to the predicted model, the recharge of groundwater resources is 21.44×108m3/a after planning, reducing 5.71×108m3/a. Reduction is mainly canal seepage. The average annual groundwater discharge into the Wuliangsu Lake t reduce 1.43×108m3/a, which may lead surface decreasing year by year. Average water depth decrease 0.75m, the general decline lead salinization reduced, some areas of larger decline may produce desertification and other environmental and geological problems.