Unified flood model with optimal zooming and linking at multiple scales

洪水灾害的频率和规模都在增加，但最近的事件表明，我们目前对洪水的了解和预测是有限的。今天，英国有520万处房产面临洪水风险，人们可能会失去生计、家园和生命，英国政府估计每年的洪水损失约为10亿英镑。因此，提高洪水管理技术，降低洪水到达和影响人类的风险是必然的趋势。可以肯定的是，改进洪水建模和预测是改变洪水管理技术的核心解决方案，这是2011-2030年英国洪水和海岸侵蚀风险管理（FCERM）研究战略的优先事项。第一个拨款提案将寻求以洪水风险管理研究联盟（FRMRC）的成果为基础。它将详细阐述和评估一个新的洪水建模框架，其特点是一个全面的数值解决方案层次结构，能够缩放到最佳尺度（空间和时间），自动适应必要的精度和效率，以及在不同尺度上交流流量信息和恢复地形数据。这项研究将是开发、评估和提供一种联合建模方法的第一步，这种方法用于模拟大规模洪水情景，真正结合了跨多个尺度的区域间相互作用。这将意味着高效、可信和非常准确的洪水模拟将在大范围内负担得起，包括密集和粗流或景观特征的领域。该模型将通过进一步发展基于不连续Galerkin （DG）有限元方法的先进洪水模型来设计，并利用多小波（MW）的适应度进行多尺度分解。该模型将利用MW的可扩展性来实现：(i)以完全解决方案驱动的方式跨空间尺度的适应性，以及（ii）大时间步长和压缩运营成本以提高效率。同时，MW-DG模型将得到计算水力学相关进展的支持，以实现实际可用性。这些将包括解决完整的2D浅水方程的准确性和自然地形数据的结合，以及为实际应用建立湿润和干燥过程的模型。这种能力甚至超过了目前最先进的洪水模型，这些模型仅限于特定的公式或网格的规模，当应用于模拟复合洪水问题时，可能会产生非系统的不确定性。这将是世界上第一次采用如此全面的方法来建立洪水风险模型。该项目涉及与亚琛工业大学<s:1>勒教授的团队合作，该团队在小波建模技术方面处于世界领先地位。新的洪水模型将在实际规模的洪水场景（例如Thamesmead地区）中进行验证，并与环境署（EA）推荐的当前洪水风险模拟计算机模型进行比较。该项目将开发一个与软件业具有战略意义的新概念，并将提供一个可供最终用户使用的新工具，以改进洪水风险评估的基础。因此，所提供的科学和模型可以在世界上产生真正的影响，并将直接受益于负责洪水风险规划和管理的政府机构和咨询工程师，即EA和Defra，以及工业软件开发商，即Innovyze ltd .。研究成果最终可以使更广泛的公众受益，改善可持续的生活方式，降低洪水风险，并降低社会经济和保险成本。最后，工业联络和传播活动，包括项目会议，计划确保新技术的采用，并使国际研究人员和英国组织受益。

Flood hazards are increasing in frequency and magnitude and yet recent events have shown that our current knowledge and forecast of flooding is limited. Today 5.2 million properties in Britain are at risk of flooding where populations could lose their livelihood, homes and lives, and the UK government estimates the annual flood damage cost to be around £1 billion. Therefore, there are inevitable trends for improving the flood management technology to reduce the risk reaching and affecting people. It is certain that improved modelling and forecasting of floods is a core solution for transforming the flood management technology, as prioritized within the 2011-2030 UK Flood and Costal Erosion Risk Management (FCERM) research strategy.This first grant proposal will seek to build upon the outputs of the Flood Risk Management Research Consortium (FRMRC). It will elaborate and assess a new flood modelling framework featured by a comprehensive numerical solution hierarchy that enables zooming to optimum scale (spatial and temporal), automatic adaption to necessary accuracy and efficiency, and communication of flow information and restoration of terrain data across different scales. The research will be the first step to develop, assess and deliver a joined-up modelling approach for simulation of large-scale flood scenarios with genuine incorporation of inter-regional interactions across multiple scales. This will mean that efficient, credible and very accurate flood simulations will be affordable at wide ranging scales, and including domains with dense and coarse flow or landscape features.The model will be designed by further developing an advanced flood model based on the Discontinuous Galerkin (DG) finite element method, with the multi-scale decomposition facilitated by the fitness of Multi-Wavelets (MW). The model will take advantage of the MW scalability to allow: (i) adaptivity across spatial scales in an entirely solution-driven manner, and (ii) large time steps and condensed operational costs to boost efficiency. Meanwhile, the MW-DG model will be supported with relevant advances in computational hydraulics to enable practical usability. These will include solving the full 2D shallow water equations for accuracy and the incorporation of natural terrain data, and modelling wetting and drying processes for practical applications.This capability is beyond even most advanced current flood models which are limited to a particular formulation or scale of the mesh and may grow unsystematic uncertainty when applied to simulate compound flood problems. This will be the first time in the world that such a holistic approach will be taken to flood risk modelling. The project involves a partnership with Prof Müller's team at RWTH Aachen as a world leader in wavelet based modelling techniques. The novel flood model will be validated for real-scale flood scenarios (e.g. the Thamesmead district) and by comparing with current computer models for flood risk simulation recommended by the Environment Agency (EA).The project will exploit a new concept that is of strategic relevance to the software industry and will provide a novel tool that can be used by end-users to improve the basis of flood risk assessment. Therefore, the delivered science and model can make a real difference in the world and will directly benefit government agencies and consulting engineers responsible for flood risk planning and management, i.e. the EA and Defra, and industrial software developers, i.e. Innovyze Ltd.The outputs of the research can ultimately benefit the wider public with improved sustainable living with risk of flooding, and reduced socio-economic and insurance costs. Finally, industrial liaison and dissemination activities, including a project conference, are planned to ensure the take-up of the new technology and benefit international researchers and UK organizations.