乌梁素海水域面积与水质参数时空变化

Spatiotemporal Changes in the Water Surface Area and Water-Quality Parameters of Wuliangsuhai Lake

摘要: 基于1977~2020年多时相Landsat系列遥感影像，采用改进的归一化水体指数提取乌梁素海水域面积，并结合半经验模型反演叶绿素a、总悬浮物、总磷、总氮和透明度等关键水质参数，分析了乌梁素海水域面积与富营养化程度的时空演变特征及其驱动机制。结果表明：1977~2020年间，乌梁素海水域面积总体呈现“先增后减、逐步趋稳”的趋势，于2008年达到峰值(375.43 km²)，至2020年稳定在333.59 km²；富营养化程度在1977~2009年间持续上升，综合营养状态指数由42.65增至54.62，2009年后随着生态补水与综合治理措施的实施，指数回落至2020年的50.18，表明治理措施已初见成效。研究验证了遥感技术在干旱–半干旱区浅水湖泊生态监测中的有效性，为乌梁素海及类似湖泊的生态治理提供了数据支撑与决策依据。

Abstract: Multi-temporal Landsat imagery from 1977~2020 was used to delineate the water surface area of Wuliangsuhai Lake via an improved Normalized Difference Water Index, and semi-empirical models retrieved key water-quality variables—chlorophyll-a, total suspended matter, total phosphorus, total nitrogen, and transparency. The spatiotemporal evolution of lake area and eutrophication, along with their drivers, was examined. Results show a “first increase, then decrease, and gradual stabilization” pattern in water surface area, peaking in 2008 (375.43 km²) and stabilizing at 333.59 km² by 2020. Eutrophication intensified from 1977 to 2009, with the trophic state index rising from 42.65 to 54.62; following ecological water supplementation and integrated restoration implemented after 2009, the index declined to 50.18 by 2020, indicating emerging effectiveness of these measures. The findings demonstrate the effectiveness of satellite remote sensing for ecological monitoring of shallow lakes in arid-semi-arid regions and provide data support and decision references for the ecological management of Wuliangsuhai and similar lakes.