Flooding represents the greatest natural threat to the UK, presenting severe risk to populations along coastlines and floodplains through extreme tidal surge and hydrometeorological events. Climate change is projected to significantly elevate flood risk through increased severity and frequency of occurrences, which will be exacerbated by external drivers of risk such as property development and population growth throughout floodplains. This investigation explores the entire flood hazard modelling chain, utilising the nonparametric bias correction of UKCP18 regional climate projections, the distributed HBV-TYN hydrological model and HEC-RAS hydraulic model to assess future manifestation of flood hazard within the Broadland Catchment, UK. When assessing the independent impact of extreme river discharge and storm surge events as well as the impact of a compound event of the two along a high emission scenario, exponential increases in hazard extent over time were observed. The flood extent increases from 197 km² in 1990 to 200 km² in 2030, and 208 km² in 2070. In parallel, exponential population exposure increases were found from 13,917 (1990) to 14,088 (2030) to 18,785 (2070). This methodology could see integration into policy-based flood risk management by use of the developed hazard modelling tool for future planning and suitability of existing infrastructure at a catchment scale.

洪水是英国面临的最大自然威胁，极端潮汐和水文气象事件给海岸线和洪泛区的居民带来严重风险。气候变化预计将通过增加发生的严重性和频率来显着提高洪水风险，而整个洪泛区的房地产开发和人口增长等外部风险驱动因素将加剧洪水风险。本次调查探索了整个洪水灾害建模链，利用 UKCP18 区域气候预测的非参数偏差校正、分布式 HBV-TYN 水文模型和 HEC-RAS 水力模型来评估英国布罗德兰流域内洪水灾害的未来表现。在评估极端河流流量和风暴潮事件的独立影响以及两者在高排放情景下的复合事件的影响时，观察到危害程度随着时间的推移呈指数增长。洪水范围从 1990 年的 197 km ²增加到 2030 年的 200 km ²，再到 2070 年的 208 km ²。与此同时，暴露人口呈指数增长，从 13,917 人（1990 年）增加到 14,088 人（2030 年），再到 18,785 人（2070 年）。该方法可以通过使用开发的灾害建模工具整合到基于政策的洪水风险管理中，以进行流域规模的未来规划和现有基础设施的适用性。