艾比湖水面近50 a变化成因分析

20世纪90年代以来，艾比湖水面面积持续增大，城区生态环境明显改善，与60、70年代水面面积急剧缩小、城区生态环境严重恶化形成鲜明对比．针对艾比湖水面面积近50a变化过程，利用入湖径流及有关水、气象资料，分析河流丰枯变化对入湖径流的影响、农业引水量与降水的关系，研究了艾比湖水面面积近50a变化成因．

Analysis on Causes of the Water Level Variation of Ebinur Lake in Recent 50 Years

Three stages, rapid shrunk from 1950 to 1977, remained stable in 1980's and escalated in 1990's, have been experienced in the process of evolution of Ebinur Lake in recent 50 years. During the period of 1950-1977,the lake area shrunk rapidly from 1 070 km 2 to 522 km 2 due to large amount of the river water were drawn into the cropland. In 1980s, the lake area remained stable at about 500 km 2 . Main causes for this can be attributed to the broken off of Kuitun River, a tributary of the lake, and the stable water discharges from Boertala River and Jinghe River. In the valleys of the two rivers, the river waters drawn into the cropland are strictly restricted by the unique hydrological features of the rivers. Since 1990's, the area of the lake enlarged yearly. According to the analysis of the hydrological records, the rivers in the lake watershed are just in a plentiful water period. Meanwhile, the precipitation in Boertala River valley increased obviously. Abundant precipitation helped to release the agricultural drought and decrease the waters drawn from the rivers. Hence, water discharges drained into the lake in 1990's increased much more than that in 1980's. It should be pointed out that abundant river waters are not the result of the melting of the glaciers in catchment of the lake but the result of climatic wetting. The rapid enlargement of the lake's area is a natural phenomenon of climatic variation of dry and wet, and can not be related with the agricultural water saving.