Study On The Change Of Ebinur Lake Basin And Hydrology Characteristic

Using hydro meteorology data during the year of1961-2010in Bortala and Jingriver basin, analyzed the trend, cycle and mutation of the precipitation, evaporationand runoff change, revealing the trend of hydrological characters in main river basinduring the near50years. Meanwhile, historical documents and all kinds of thematicmap data are used to analyze the water distribution of temporal and spatial variation inthe basin during the near50years, at the same time have some study on the changemechanisms of the basin and provide some concrete theory for sustainable utilizationof water resources in this basin.Optimize water resources allocation as a watershed, rationalplanning of water resources provide a theoretical basis, to carry out the changes in the river basinof river systems and the ecological runoff theory, methodology and its application research hasimportant practical significance and value.(1) In the near50years, precipitation shows increasing trend in the Bortala andJing basin, especially during the late1990s’, precipitation is significantly more, thegrowth of precipitation rate in the summer half year is higher than in the winter. Therunoff of Bortala river reduces in per10years the rate of0.318m~3/s. The cumulativereduction of runoff is0.57×10~8m~3which is lower than the average value by8.94%.The runoff of Jing river reduces in per10years the rate of0.229m~3/s. The cumulativeincreace of runoff is0.32×10~8m~3which is higher than the average value by5.42%.(2) In the basin, there is no big change in secular variation of the runoff of themain rivers; the variation coefficient is0.11-0.14. The downstream of Bortala Rivershows decreasing trend while the Jing River shows increasing trend. According to thepeak rate and wet-dry season of the two main rivers, it can be showed that the rain andsnow melt waters’ supply on the runoff of the Bortala river is decreasing while theirsupply on the runoff of the Jing river is increasing.(3) There is a preferable synchronism between the growth of length and numbers of the two rivers, and their correlation coefficient is0.98(significance level is0.001),river total length increase from1756km to2144.5km in from1966to1995, after thatdecrease to1022km in2010, the total length reduce734km; river numbers decreases50to21from1966to2010,the total number reduce to29. The runoff of Bortala rivershows decreasing trend compare to1960s,the relevant river network density andgrowth coefficients also has the trend of decreasing and this restraining thedevelopment of river branches. The runoff of Jing river shows increasing trendcompare to1960s,the relevant river network density and growth coefficients also hasthe trend of increasing and this prompting the development of river branches.(4) Due to natural and human factors, water resources in the basin showsdecrease-increase-decrease trend from1960s to today. Because of human factors suchas, population increase, reservoir construction, Inter-basin water diversion project,crop irrigation, urban water supply and drainage, it is directly changed thehydrological characters and temporal and spatial variation of the Bortala and Jingriver basin.