An Investigation On Water Balance In The Area Of Sumujilin Lakes In Badain Jaran Desert, China

The Badain Jaran esert, on the Alxa Plateau of China, has been a focus ofinternational and domestic studies. So far no final agreement has been concluded onthe source of lake and the cycle of groundwater. The Area of Sumujilin Lakes in thesoutheast Badain Jaran Desert, within the surface of the watershed, was chosen asthe study area in this article. This paper is used to study the Area of Sumujilin Lakeswith the methods of water balance and numerical simulation by installations, actualsurvey and data analysis.The evaporation of the south Sumujilin Lake, from September,2012to August,2013, was1261mm, by using the meteorological station we have installed on thesouth Sumujilin Lake. The water level fluctuation of south lake was0.217m. As wellas the water level fluctuation of groundwater, beside the south lake, was0.179m.With the method of water balance, using the annual average distribution ratio ofevaporation and precipitation, lake’s water level fluctuations could be got. The resultsshowed that if there were no other sources, the rainfall within the watershed could notsupport the evaporation of the lake and groundwater. And the recharge from deepconfined aquifers was an important element to maintain the lake equalization.This paper established a hydrogeological model with three layers in the Area ofSumujilin Lakes region. And then four kinds of steady flow scenario simulations weredesigned through MDFLOW. The results calculated from the model show that, themore reasonable evaporation of lake ranged from1400to1600mm/a, and the deepgroundwater head ranged from1184.8to1185.3m. As the same time, the analysis ofequilibrium elements in scenario simulations show that, lake water is mainly from thelateral recharge of unconfined aquifer, and the main source of the unconfined aquiferis the leakage recharge from the third layer groundwater.On the base of steady flow simulations, the unsteady cycle flow simulations withfour kinds of scenario simulations were built. Lake’s water level fluctuations weremainly effected by Evaporation. While groundwater level fluctuations were mainlyeffected by specific yield and evaporation. The results about water level fluctuations, under different conditions of evaporation, with the methods of water balance andnumerical simulation were fundamentally equivalent. But the numerical simulationmethod was more realistic about the minimum and maximum occurrence. In addition,the groundwater level dynamics could be got only by numerical simulation method.