River Flood Maps (FRM_FH_RIVER_VELOCITY_DIRECTION_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.本批洪水危险地图（flood hazard maps）的编制，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》（Flood Risk Management (Scotland) Act 2009）所规定的发布洪水危险地图的义务。本批地图展示了海洋、河流及地表水引发洪水的风险区域范围。 针对河流洪水，共提供以下三类概率等级的灾害数据： - 高概率：对应10年一遇重现期（return period） - 中概率：对应200年一遇重现期 - 低概率：对应1000年一遇重现期，以及结合2080年代英国气候预测2009（UKCP09）高排放情景（high emissions scenario）下的气候变化影响的200年一遇重现期情景 河流洪水危险图将展示以下内容（如可获取）： - 洪水淹没范围（Flood extent） - 洪水水深（Flood depth） - 适宜场景下的洪水流速（Flood velocities） 本次采用的气候变化情景，基于英国气候预测2009（UKCP09）针对2080年代高排放情景下的95百分位（95%ile）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、建模方法及影响结果的可信度，当前分为四个等级进行展示。 中、低概率洪水情景的选取，是为与苏格兰规划政策（Scottish Planning Policy）中采用的重现期标准保持一致；而高概率情景的选取，则反映了近数十年来实际观测到的洪水事件特征。