Shi Xiaohong, Wang Shihuan, Zhao Shengnan, Sun Biao, Yu Haifeng, Zhang Fan, Zhang Qiying
Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot, 010018, China; State Key Laboratory of Water Engineering Ecology and Environment in Arid Area, Inner Mongolia Agricultural University, Hohhot, 010018, China; State Gauge and Research Station of Wetland Ecosystem, Wuliangsuhai Lake, Inner Mongolia, Bayan Nur, 014404, China.
Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot, 010018, China.
J Environ Manage. 2025 Sep;391:126491. doi: 10.1016/j.jenvman.2025.126491. Epub 2025 Jul 11.
Under the combined impacts of climate change and human activities, lakes in arid and semi-arid regions are universally confronting critical challenges including water scarcity, surface area shrinkage, and water quality deterioration. As one of the principal measures for ecological restoration of irrigation-district lakes, ecological water replenishment projects have been widely implemented. However, given the inherent complexity of lacustrine systems, the efficacy of ecological water replenishment in enhancing water quality and hydrological exchange capacity remains scientifically contentious. This study utilizes the MIKE 21 model to develop a 2D hydrodynamic model based on measured data (2011-2021), evaluating both the water exchange capacity and its influencing factors for a large semi-arid irrigation district lake under ecological water replenishment conditions. Furthermore, a modified Comprehensive Water Quality Identification Index (WQI) was employed to evaluate the characteristics of water quality changes. The results indicate that: (1) Over the 11-year period, the water renewal cycle shortened from 28-185 days to 25-115 days with increasing inflow to the lake. The water exchange capacity exhibited significant spatial heterogeneity. This was influenced by factors such as the location of the water replenishment inlet, lake topography, and aquatic vegetation. (2) As a typical artificially controlled lake in a semi-arid region, the continuous water replenishment rate over a specific time period determined the seasonal differences in water exchange rate. The variable inputs from multiple water sources led to varying water exchange rates among different years. (3) During the implementation of ecological water replenishment, the lake water quality improved significantly. Further integration of ecological water replenishment with point-source、non-point-source、and internal pollution control is necessary for the sustainable development of irrigation district lakes. Our study dynamically demonstrates the effects of external disturbances, such as ecological water replenishment projects, on the restoration and management of irrigation district lakes and provides theoretical and data support for sustainable management decision-making of artificially controlled lakes in irrigation districts.
在气候变化和人类活动的共同影响下，干旱和半干旱地区的湖泊普遍面临着水资源短缺、湖面萎缩和水质恶化等严峻挑战。作为灌区湖泊生态修复的主要措施之一，生态补水工程已得到广泛实施。然而，鉴于湖泊系统固有的复杂性，生态补水在改善水质和水文交换能力方面的效果在科学上仍存在争议。本研究利用MIKE 21模型，基于实测数据（2011 - 2021年）建立二维水动力模型，评估了生态补水条件下大型半干旱灌区湖泊的水交换能力及其影响因素。此外，采用改进的综合水质标识指数（WQI）来评估水质变化特征。结果表明：（1）在这11年期间，随着入湖流量增加，湖水更新周期从28 - 185天缩短至25 - 115天。水交换能力呈现出显著的空间异质性，这受到补水口位置、湖泊地形和水生植被等因素的影响。（2）作为半干旱地区典型的人工控制湖泊，特定时间段内的持续补水速率决定了水交换速率的季节差异。多个水源的可变输入导致不同年份的水交换速率有所不同。（3）在生态补水实施过程中，湖泊水质显著改善。为了灌区湖泊的可持续发展，有必要将生态补水与点源、非点源及内源污染控制进一步结合。本研究动态展示了生态补水工程等外部干扰对灌区湖泊修复和管理的影响，为灌区人工控制湖泊的可持续管理决策提供了理论和数据支持。
