River Flood Maps (FRM_FH_RIVER_VELOCITY_H)

These maps have been produced to meet SEPA’s duty to publish flood hazard maps as set out in the Flood Risk Management (Scotland) Act 2009. The maps show where there is a risk of flooding from the sea, from rivers and from surface water.The following probabilities are available for river flooding: - High - 10 year return period - Medium - 200 year return period - Low - 1000 year return period and 200 year return period plus climate change using the UKCP09 high emissions scenario for the 2080s.The river hazard maps show (where available): - Flood extent - Flood depth - Flood velocities where appropriate. The climate change scenario has been defined by United Kingdom Climate Projection 2009 (UKCP09) predictions for 2080 high emissions 95%ile predictions. Velocity is presented, where appropriate; this is determined by considering the confidence in input data, modelling method and impact. It is currently represented as one of four bandsMedium and low probability flood events were selected for consistency with return periods used in Scottish Planning Policy, whereas the high probability was chosen as it is reflective of observed events experienced over the last few decades.本批洪水灾害地图的制作，旨在履行苏格兰环境保护局（SEPA）依据《2009年洪水风险管理（苏格兰）法案》所规定的发布洪水灾害地图的法定义务。本批地图展示了海洋、河流及地表积水引发的洪水风险区域。 针对河流洪水，提供以下不同概率等级的灾害场景： - 高概率：10年一遇重现期 - 中概率：200年一遇重现期 - 低概率：1000年一遇重现期，以及基于2080年代英国气候预测2009（UKCP09）高排放情景的200年一遇重现期叠加气候变化影响的场景。 河流灾害地图将（在数据可用时）展示以下信息： - 洪水淹没范围 - 洪水水深 - 适宜场景下的洪水流速 本研究所用的气候变化情景，基于英国气候预测2009（UKCP09）针对2080年高排放场景的95百分位预测结果设定。流速信息仅在适宜场景下提供，其生成需综合考量输入数据可信度、建模方法及影响程度，目前将流速划分为四个等级进行展示。 本次选取中、低概率洪水场景，是为了与苏格兰规划政策中采用的重现期标准保持一致；而高概率场景的选取，则因其能够反映近数十年间实际观测到的洪水事件特征。