River Flood Maps (FRM_FH_RIVER_VELOCITY_L)

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》所承担的发布洪水危险地图的法定义务。本批地图涵盖了海洋、河流及地表水引发洪水的风险区域。 针对河流洪水，本次数据集提供以下概率分级的洪水风险数据： - 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，以及基于2080年代英国气候预测2009（UKCP09）高排放情景的气候变化影响修正后的200年一遇重现期洪水。 河流危险地图将在数据可获取的前提下展示以下内容：洪水淹没范围、洪水水深，以及适宜场景下的洪水流速。 本气候变化情景基于英国气候预测2009（UKCP09）针对2080年高排放情景下95%分位数的预测结果设定。流速信息将在适宜情况下予以展示，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。目前流速被划分为四个等级之一。中、低概率洪水事件的选取与苏格兰规划政策中采用的重现期保持一致，而高概率洪水事件的选取则反映了过去数十年间已观测到的洪水灾情。