Newton Fund: Salt intrusion: Understanding the Pearl River Estuary by Modelling and field Experiments (SUPREME)

三角洲和河口的盐水入侵是水盐动态复杂相互作用的结果，受气候变化和人为干预的影响。在中国珠江口（PRE），这些变化危及淡水供应，影响4000多万人。PRE的复杂形状（几何形状和水深测量）使得盐侵过程本质上是三维的。然而，由于以往的研究主要局限于纵向变异，目前的知识不足以揭示盐的纵向和横向相互交织的运输机制。SUPREME项目的总体目标是了解这些三维盐运输机制，以及它们对外部强迫和当地地理形状变化的敏感性。本项目开发/应用的知识和工具将有助于评估缓解盐侵变化的可能措施的有效性。我们采用综合方法，包括理想化和数值模拟，以及现场测量和数据分析。理想化的模型包括基本的物理和大规模的几何/测深特征在一个示意图的方式。因此，它们专门用于阐明控制物理机制之间的相互作用。复杂的数值模型将这些结果扩展到瞬态强迫条件，并提供特定地点的信息。这两种方法的结合为新的现场测量和现有数据提供了洞察力，并得到了激励和验证。荷兰、中国和英国的这个联合项目为了解PRE和其他河口的盐动态提供了一个新的综合框架。它还为这些地区的河口管理提供了更坚实的科学依据，以防止破坏性的盐水入侵。为了给我们的工作提供更普遍和全球的前景和适用性，我们将把PRE的盐入侵与另外两个河口的盐入侵进行比较：默西（英国）和埃姆斯（荷兰/德国）。英国对该项目的贡献将由国家海洋学中心提供。英国研究工作的主要重点将是开发和实施最先进的非结构化网格，PRE的数值模型和其他研究领域。该数值模型将用于进行预后和诊断调查。我们将回顾一系列未来气候变化和人类干预的情景（例如，海平面上升，河流径流，疏浚和淡水提取）。英国的贡献还将包括对默西河口的长期观测，这将作为对河口盐入侵的低成本长期监测的试点研究，从而为一个框架提供概念证明，该框架将广泛适用于世界上其他河口和三角洲系统，包括PRE。

Saltwater intrusion in deltas and estuaries results from the complex interaction between water and salt dynamics, and is affected by climate change and human intervention. In the Pearl River Estuary (PRE) in China, these changes endanger freshwater availability affecting over 40 million people. PRE's complex shape (geometry and bathymetry) makes salt intrusion processes inherently three-dimensional. However, as previous research was mainly restricted to longitudinal variability, current knowledge is insufficient to unravel the interwoven longitudinal and lateral salt transport mechanisms.The overall aim of the SUPREME project is to understand these three-dimensional salt transport mechanisms, and their sensitivity to variations in external forcing and local geographic shape. The knowledge and tools developed/applied in this project will help assess the effectiveness of possible measures to alleviate undesired changes in salt intrusion. We adopt an integrated approach, involving both idealized and numerical modelling, as well as field measurements and data analysis. Idealized models include the essential physics and large-scale geometrical/bathymetrical features in a schematised way. Thus, they are specifically geared to clarify the interactions between governing physical mechanisms. Complex numerical models extend these results to transient forcing conditions and provide site-specific information. The combination of these two approaches provides insight, motivated and validated by new field measurements and existing data.This joint project between the Netherlands, China and the UK presents a new integrated framework to understand salt dynamics in the PRE and other estuaries. It further provides a more solid scientific basis for estuarine management to prevent damaging saltwater intrusion in these regions. In order to provide more generic and global outlook and applicability to our work, we will compare salt intrusion in the PRE to salt intrusion in two other estuaries: the Mersey (UK) and the Ems (Netherlands/Germany).The UK contribution of the project will be delivered by the National Oceanography Centre. The main focus of the UK research effort will be to develop and implement a state-of-the-art unstructured grid, numerical model of the PRE and other study areas. This numerical model will be used to conduct prognostic and diagnostic investigations. We will review a range of scenarios of future climate change and human interventions (e.g., sea level rise, river runoff, dredging, and freshwater abstraction). The UK contribution will also include long-term observations for the Mersey estuary, which will act as a pilot study for low-cost, long-term monitoring of salt intrusion in an estuary, thus providing proof-of-concept for a framework, which will be broadly applicable to other estuarine and deltaic systems in the world, including the PRE.