博斯腾小湖最低生态水位与水量盈缺分析

近年来，博斯腾湖小湖水位大幅波动引发了湖区生态环境问题，基于最低生态水位的湖泊水量盈缺分析对小湖水量调度和生态保护有积极意义。基于1991—2019年达吾提闸实测小湖水位数据，结合湖盆DEM数据和遥感NDVI数据，分别采用年保证率设定法、湖泊地形分析法和曲线相关法计算小湖区最低生态水位；并利用其他水文、气象和农业活动和湖区水量调控数据，使用主成分分析法解析小湖缺水的主要驱动因子。结果表明:博斯腾湖小湖最低生态水位为1047.18 m，多年平均满足率为31.03%。1991—1998年、2005—2015年和2017年间博斯腾小湖区发生了生态缺水，平均缺水量为0.69×108 m3。上游来水量是小湖生态需水保证情势的主要驱动因素，农业活动和宝浪苏木水量调节活动次之，气候变化影响相对较小。2000年之前，生态缺水主要由湖区水位调控产生；2000年之后，灌区农业取水成为生态缺水主要诱因。该研究结果可以为博斯腾湖小湖水量调控和湿地生态系统恢复保护提供科学依据。

ANALYSIS OF MINIMUM ECOLOGICAL WATER LEVEL AND WATER SURPLUS IN XIAOHU LAKE DISTRICT IN BOSTEN LAKE

In recent years, ecological problems occurred due to the large fluctuations in the water level of Xiaohu Lake distinct in Bosten Lake. Therefore, analysis of water deficit relying on the lowest ecological water level, has a positive significance for the water regulation and ecological protection for Xiaohu Lake. Based on the measured Xiaohu Lake water level data in Dawuti sluice from 1991 to 2019, this study combined with the DEM data and remote sensing inversion NDVI data of the lake basin, using the annual guarantee rate setting method, lake morphology analytic approach and curve correlation method, to calculate the minimum water level in Xiaohu Lake. Relying on the ecological water level data, combined with hydrological, meteorological and agricultural activities, and water regulation data in the lake area, the main driving factors for water scarcity in Xiaohu Lake were analyzed using principal component analysis. The results showed that the minimum ecological water level of Bosten Lake was 1047.18 m, and the average satisfaction rate for many years was 31.03%. In year 1991—1997, 2005—2015, 2017, ecological water shortage occurred in the Bosten Xiaohu Lake District, with an average water shortage of 0.69×108 m3. The amount of upstream water was the main factor for the ecological water demand of Xiaohu Lake District, followed by agricultural activities, water regulation activities of Baolangsumu and the impact of climate change was relatively slighter. Before 2000, the ecological water shortage was mainly due to the regulation of the water level in the lake area; after 2000, agricultural water withdrawal in the irrigation area became the main cause of ecological water shortage. Scientific evidences could be provided by the research for the regulation of the water volume of Xiaohu Lake District of Bosten Lake and the restoration and protection of the wetland ecosystem.