平原河网区水动力重构理论与实践

Theory and Practice of Hydrodynamic Reconstruction in Plain River Networks

我国平原河网地区地势低洼,河道比降平缓,水动力弱,加上密集的人类活动,水安全问题十分突出,比如洪涝频发、水体自净能力差、水生态系统脆弱等。本文研究发现这些问题都与水动力有关,水流能量时空分布失衡是产生这些水问题的共同本源,由此,创建了平原河网区水动力重构理论。该理论在水量调控的基础上,深挖水动力及有限能量在水生态环境改善中的作用,优化布局水闸、泵站等水利工程体系,充分挖潜工程的综合效益,通过重构水动力时空分布来满足平原河网区复杂水问题统筹治理的需求。在此基础上,建立了完整的弱动力平原河网区多尺度水动力重构、多目标水力调控的理论方法和技术体系,提出了平原河网区水问题统筹治理原则。最后以扬州主城区河网活水提质为例,介绍该理论的实际应用及效果。

The river networks in the plains of China are in low-lying terrain with mild bed slopes and weak hydrodynamics conditions.Filled with intense human activities,these areas are characterized by serious water security problems,for example,frequent floods,poor water self-purification capabilities,and fragile water ecosystems.In this paper,it’s found that all these problems are related to hydrodynamics,and the spatiotemporal imbalance of river network hydrodynamics is identified as the common cause of these water-related problems.From this,a theory for the hydrodynamic reconstruction of plain river networks is proposed.In addition to the importance of the flow volume,this theory highlights the role of hydrodynamics and limited energy in improving the ecological water environment.The layout of water conservancy project systems(e.g.,sluices and pumping stations)is optimized to fully tapping the potential integrative benefit of projects.The optimal temporal and spatial distributions of hydrodynamic patterns are reconstructed in order to meet the needs of the integrated management of complex water-related problems in river networks.On this basis,a complete theoretical method and technical system for multiscale hydrodynamic reconstruction and multi-objective hydraulic regulation in plain river networks with weak hydrodynamics is established.The principles of the integrated management of water problems in river network areas are put forward.The practical application and efficacy of the theory are demonstrated through a case study aiming to improve the water quality of the river network in the main urban area of Yangzhou City.