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.本批洪水危险地图系为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》规定的法定发布职责而制作。本批地图展示了海洋、河流及地表水引发洪水的风险分布区域。 针对河流洪水场景，本次提供以下概率分级的洪水危险地图： - 高概率：对应10年一遇重现期 - 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、将气候变化影响纳入后的200年一遇重现期情形 河流危险地图将（在可获取的前提下）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 本次采用的气候变化情景系基于英国气候预测2009（UKCP09）针对2080年高排放情景下的95%分位数预测结果制定。流速信息将在适宜场景下予以展示，其判定需综合考量输入数据、建模方法及影响的置信度，目前分为四个等级进行呈现。选取中、低概率洪水事件是为与苏格兰规划政策中采用的重现期标准保持一致，而高概率洪水事件的选取则因其能够反映近数十年间已观测到的洪水事件特征。