Analysis Of The Hydrological Characteristics And Water Balance Of Bosten Lake

Bosten Lake was the largest freshwater lake inland China, located in the arid region of the central area of Asia. In the past50years, the lake water level is changed dramaticly in the impact of climate fluctuation and human activities, which caused a series of environment problems, such as water quality is worse, soil salinization become aggravate, flood and so on. It is important to study on the lake water balance for revealing the process of the lake hydrology and formulating the method of solving the water problem.In this paper, based on the hydrology and meteorology data from1958to2009, the seasonal variation and the inter-annual variation characteristics and the factors’influence each other of hydrological and meteorological are analyzed, and the water balance of Bosten lake is estimated and calculated.The results shows that the seasonal variation characteristics of the runoff, water level, precipitation and evaporation are significant; The runoff at Dashankou station and the precipitation of Bosten lake concentrate in the summer separately account for44.82%,56.07%of the total, and the water amount of four seasons vary greatly. The evaporation in the spring and summer are more than the other two seasons,respectly account for33.85%,44.04%of the total. The inter-annual variation of runoff and water level are quite obvious and the water level presents the trend of drop—rise—drop; The precipitation is less and the evaporation is more, the inter-annual variation of precipitation is not significant, but the evaporation is opposite, presents a rising trend. The precipitation can restrain the evaporation. The precipitation of source region in the upper reaches is the major supply of the Kaidu River runoff. The lake water level is influenced by the Climate and human activities. Climate can change the runoff through temprature and precipitation to affect the water level, and human activities also can change the surface runoff outcome to influence the water level.In the period from1958to2009the total water into the lake is14.23×108m3/a, include the surface runoff income ranges from5.24to35.46×108m3/a (average:13.49×008m3/a), account for94.80%of the total; the precipitation ranges from0.19to1.59×108m3/a (average:0.74×108m3/a), account for5.20%; the water out from the lke is14.58×108m3/a, include the output ranges from1.37to13.61×108m3/a(average:5.88×108m3/a), account for39.58%; the evaporation ranges from5.94to11.66×108m3/a (average:8.70×108m3/a), account for60.42%; the change in the amount of storage capacity ranges from-8.97to7.74×108m3/a (average:-0.74×108m3/a) and the residual water(drain inflow and subsurface water) ranges from-5.62to16.96×108m3/a (average:0.39×108m3/a), only account for2.89%of the surface runoff income. The analysis also showed that surface runoff income and outcome from the lake are the main factors to influence the water variation of Bosten Lake.