The Groundwater Numerical Simulation And Overdraft Region Eualuation For Qitai County Plain Area In Xinjiang

It was a sort of potential calamity gender crises that underground water resources surfeit exploitation, however, it was ignored by folk station generally. Thereby, it result in huge economic loss and environmental geology calamity. The county of Qitai is situated in semi-arid zone in Xinjiang province. Because bare of surface water, result in groundwater severity overdraft and water table abidance fell, finally, water resources face crises. Want to relieve and keep out of these imperil, simulation and analyses of groundwater system must be further discussed in platform County of Qitai, carrying out precise groundwater resource evaluation. It is the foundation of scientific management and effective exploitation.In this paper, first summarize fundamental state and cum perennial change law,then adopt water budget method proceed introduction underground water resources gauge reckon,combine with GIS, RS, DEM technology,establish tridimensional numerical model on the base of processing MODFLOW, then get precise calculation of water resources fairly in the county of Qitai. On the foundation of numerical simulation results, we can evaluate overdraft area.The main conclusions as follows:(1) Have (two)application numerical simulation calculation got:form 1992 to 2000, the average groundwater recharge rate is 32678×104m3/a in Qitai plain. thereinto , side replenishment is 3377×104m3/a,watercourse influent seepage, channel influent seepage, field infiltration, reservoir influent seepage transformation recharge rate is 29301×104m3/a. Transformation recharge rate occupy overall logistical demand 89.7%, the groundwater overall drainage is 38873×104m3/a,the groundwater withdraw is 35949×104m3/a, the groundwater overdraft is 16342×104m3/a,the allowable withdrawal of groundwater is 19607×104m3/a.(2) The trend of 26 long-time observation holes is decline, the withdrawal coefficient is 0.6 in Qitai county. The overdraft coefficient is 0.83 from 1992 to 2000. The overdraft extent can be divided into two areas in the whole county: one is filler area which is county-centered, another is lie in adjacent 110 farm to Qitai county farm.