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.本批洪水危险性地图的制作，旨在履行苏格兰环境保护署（SEPA）依据《2009年洪水风险管理（苏格兰）法案》所规定的发布洪水危险性地图的法定职责。本批地图展示了受海洋、河流及地表水引发洪水威胁的区域。针对河流洪水，共提供以下概率等级的相关数据： - 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，以及结合2080年代英国气候预测2009（UKCP09）高排放情景的200年一遇气候变化修正洪水风险。 河流危险性地图将在数据可用时展示以下内容： - 洪水淹没范围 - 洪水水深 - 适宜场景下的洪水流速。 本次采用的气候变化情景，基于英国2009年气候预测（UKCP09）针对2080年高排放情景下的95百分位预测结果设定。流速仅在适宜场景下予以展示，其判定依据为输入数据、建模方法及影响评估的置信度水平，目前分为四个等级。中、低概率洪水事件的选取标准，与苏格兰规划政策中采用的重现期保持一致；而高概率事件的选取则参考了近数十年来实际观测到的洪水案例。