海陆交互作用对河口区盐水入侵的驱动效应研究

The estuary is characterized as humid climate, crisscrossed rivers, prosperous economy, densely population and urban concentration. Furthermore, influenced by the urban construction, sand excavation in river channel, outlet improvement, estuarine reclamation, waterway dredging, bridge building, sea-level rise, and other more factors, the hydrological and hydrodynamic processes, water and salt transport of estuary are more multi-element superposition driven and have more multi-level complex structure and non-natural transmission attributes than those of a single waterway. As a result, water resources issues of this region caused by saltwater intrusion become more prominent and more uncertain. The project carries out the research from the process of evolution law recognition, mechanism diagnosis, and multi-time scale forecast of saltwater intrusion in the estuary under the interaction of sea and land. We want to put forward some innovative achievements on mechanism diagnosis of saltwater intrusion based on the combination of statistical analysis, physical model and numerical simulation, construction of multi-time scale saltwater intrusion prediction model with real-time rolling modification function and other aspects so as to scientifically reveal the driving effect of saltwater intrusion in the estuary under the interaction of sea and land and realize accurate prediction and forecast of saltwater intrusion. This research will enrich and improve the hydrology and water resources system theory in the estuary, and provide a sound theoretical base and technology support in response to water resources security for the mega-city regions of Pearl River Delta, Yangtze River Delta and Bohai Bay.

河口区气候湿润、水系交错、经济发达、人口密集、城镇集中，水文水资源系统面临城市建设挤占河道、河道挖沙、口门整治、滩涂围垦、航道疏浚、桥梁建造、海平面上升等海陆交互作用，其水文水动力过程、水盐物质输移等均较单一河道更具多要素叠加驱动、多层次复杂结构与非自然传输属性，由盐水入侵引发的水文水资源问题突出且更具不确定性。本课题以珠江河口区为实践，开展海陆交互作用下河口区盐水入侵演变规律识别—机理诊断—多时间尺度预报的全过程研究，在基于统计分析、物理模型与数值模拟相结合的盐水入侵机理诊断，基于嵌套实时滚动修正的盐水入侵多时间尺度预报模式构建等方面提出创新性成果，科学揭示海陆交互作用下珠江河口区盐水入侵的演变规律，实现盐水入侵的精准化预测预报，丰富与完善河口水文水资源系统理论方法，为我国珠江三角洲、长江三角洲、环渤海湾等滨海特大城市群水安全保障提供理论依据和技术支撑。

河口区气候湿润、水系交错、经济发达、人口密集、城镇集中，受人类活动与海平面上升共同驱动，其水文水动力过程、水盐物质输移等均较单一河道更具多要素叠加驱动、多层次复杂结构与非自然传输属性。本项目以珠江河口为实践，以揭示海陆交互作用下河口区盐水入侵演变规律为轴心，以实现河口区盐水入侵精准化预报为主线，基于高精度观测资料以及高频采样实时数据收集与分析，系统诊断了珠江河口区盐水入侵现状，构建了珠江河口区大尺度具有物理机制的盐水入侵物理水槽和数值模拟模型，研究海陆要素对河口区盐水入侵的驱动效应；融合机器学习模型、小波分析方法与实时预报技术，创新性构建了珠江河口区盐水入侵短中长期预报模型，大幅提升了河口区盐水入侵中长期精准预报。取得了如下创新性研究成果：.（1）基于河口区盐水入侵多层次复杂结构、非自然传输属性等特点，构建了基于小波分析理论的盐水入侵时效分析方法、基于相似性原理的盐水入侵水槽模型、基于FVCOM的珠江河口大尺度水动力盐度耦合模型，从统计分析与物理机制两个层面有效揭示了海陆交互作用对河口区盐水入侵的复杂驱动机制，突破单一统计方法或模型无法综合解析盐水入侵现象与物理机制的局限。.（2）基于海陆要素对盐水入侵的多层次交互叠加驱动特征，运用基于符号检验的预报因子迭代挑选方法，构建适宜于短、中、长期盐水入侵预报因子集，解决河口区盐水入侵预报不确定性因子多的难题；创新性研发了基于机器学习的珠江河口盐水入侵短、中、长期实时滚动嵌套的盐水入侵模型，有效解决盐水入侵预报预见期短、预报精度低的难题。.通过本项目研究，已形成了较完整的珠江河口盐水入侵演变规律与预报技术方法，培育了一支服务河口水文过程的研究团队。科研成果突出，在国内外重要期刊公开发表论文32篇，论著1部，专利与软著7项，省部级以上奖励2项，相关成果已经在2021-2022连续两年珠江河口极端咸潮干旱事件中得到运用，取得了良好效果。本项目研究丰富与完善了河口水文水资源理论方法，可为珠江三角洲、长江三角洲、环渤海湾等滨海特大城市群水安全保障提供理论和技术支撑。