气候变化下季节分层型水库的热力及溶解氧层化过程演变研究

Under the influence of climate change, reservoir stratification characteristics would change due to the change of thermodynamic process, which results in the alteration of mixing and transportation regime in reservoirs. Identifying the evolution feature and driving force of this trend process is the premise to recognize that how the environmental characteristics of reservoirs would be affected by climate change during future operation. Therefore, this proposal intends to focus on seasonal stratified reservoirs with annual cycling of stratification and mixing, selecting representative samples from the major climatic zones in China, and studying the response of reservoir stratification characteristics to climate change and its environmental effects. Numerical simulation, historical data investigation and field observation will be conducted. Based on historical climate warming trend, combined with historical observation data and numerical simulation inversion, this research plan to interpret the trend influence of climate change on reservoir stratification, identify the response sensitivity of reservoirs in different climatic zones to climate change, and analyzes the thermodynamic and hydrodynamic mechanisms underlay it. Meanwhile, the evolution rules of stratification characteristics under different future climate change scenarios will be predicted, and the accompanying environmental effects will be evaluated with dissolved oxygen as the indicator factor, so as to comprehensively deconstruct the different influences of different future climate change scenarios. The results would be helpful to deepen scientific understanding of climate change and its impacts, and to provide evidence for adaptive management decisions.

水库层化特性在气候变化的影响下因热力学过程的改变而发生变化，从而引起物质输运交换机制的异动。揭示这一趋势性过程的演变规律和驱动机制，是认清水库环境特征在未来长时期运行中受气候变化影响的前提，而我国相关研究较为匮乏。因此本项目拟关注具有年内分层-混合这一循环特征的季节分层型水库，在我国主要气候带选择选取代表样本，结合数值模拟、历史资料调查和现场观测等手段，开展水库分层特性对气候变化的响应规律及环境效应研究。基于历史性气候变暖趋势，结合历史观测资料和数值模拟反演，解译气候变化对水库分层特性产生的趋势性影响，并识别不同气候带水库对于气候变化的响应敏感性，剖析其中热力学和水动力学机制；同时预测不同未来气候变化情景下的分层特性演变规律，以溶解氧为指示性因子评估伴随的环境效应，进而综合辨识不同未来气候变化幅度产生的影响。成果将有助于加深对气候变化及其影响的科学认知，为适应性管理决策提供论证依据。

气候变化对湖库的热力条件和混合特征会产生系统性影响，由此引发的生态环境风险已成为近年来环境水力学和湖沼学领域的前沿和热点问题之一。本项目采用数值模拟为主要研究手段，结合原型观测及历史资料调查分析，聚焦在我国有广泛分布且受气候变化影响较大的季节分层型水库，基于IPCC 公布的未来气候变化情景（RCP 2.6、4.5、6.0、8.5），开展了水库热状态及层化过程在气候变暖趋势影响下的演变规律预测模拟，重点阐释了热状态及层化特性演变过程中水库内水动力条件对其的干预机制，并以溶解氧为指示性指标评估对应情景的环境效应，进而瞄准水库的可人工调节属性，探明了水库适应性管理措施对气候变化不利影响的改善效果。成果丰富了气候变化对湖库系统影响的科学认知，又为探寻未来可行的应对手段提供了科学依据。