surface water and small watercourses flooding (medium likelihood) - sepa

The following probabilities are available for surface water & small watercourse flooding: High - 10 year return period, Medium - 200 year return period, Low - 1000 year return period, and the 200 year return period plus climate change using rainfall uplifts for 2070 from the FUTURE-DRAINAGE project. The FUTURE-DRAINAGE project is based on analysis of the UK Climate Projections 2018 (UKCP18) high resolution (UKCP Local) projections for Representative Concentration Pathway 8.5 (RCP8.5). The climate scenario has been defined by the 50th percentile for 2070. The surface water and small watercourses hazard maps show (where available): Flood extent, flood depth and flood velocities (where appropriate). https://map.sepa.org.uk/server/rest/services/Open/Flood_Maps/MapServer When using this dataset, a visibility scale has been set due to the size and number of records.针对地表洪水与小型河道洪水，现有如下概率等级：高风险对应10年一遇重现期，中风险对应200年一遇重现期，低风险对应1000年一遇重现期；此外还包含FUTURE-DRAINAGE项目中基于2070年降雨增幅得到的、叠加气候变化影响的200年一遇情景。 FUTURE-DRAINAGE项目基于对英国气候预测2018（UK Climate Projections 2018，简称UKCP18）中典型浓度路径8.5（Representative Concentration Pathway 8.5，简称RCP8.5）的高分辨率（UKCP Local）预测结果的分析。 该气候情景以2070年的50百分位值进行定义。 地表洪水与小型河道灾害地图（若有可用数据）将展示洪水淹没范围、洪水深度及适宜场景下的洪水流速。 https://map.sepa.org.uk/server/rest/services/Open/Flood_Maps/MapServer 鉴于该数据集的记录体量与数量，使用时已配置可见性比例尺。