River Flood Maps (FRM_FH_RIVER_VELOCITY_M)

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.本套地图的编制旨在履行苏格兰环境保护局（Scottish Environment Protection Agency，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地图的法定职责。本套地图展示了海洋、河流及地表水引发的洪水风险区域。 针对河流洪水，本次提供以下概率等级的相关数据： - 高概率：10年一遇重现期（10 year return period） - 中概率：200年一遇重现期（200 year return period） - 低概率：1000年一遇重现期（1000 year return period），以及采用2080年代英国气候预测2009（UK Climate Projections 2009，UKCP09）高排放情景的、叠加气候变化影响的200年一遇重现期情景。 河流危险地图将在数据可用时展示以下内容： - 洪水淹没范围（Flood extent） - 洪水水深（Flood depth） - 适用场景下的洪水流速（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年代高排放情景的95百分位（95%ile）预测结果。仅在适用场景下才会展示流速数据，其展示与否需综合考量输入数据的可信度、建模方法及影响效果。流速目前分为四个等级进行标注。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，而高概率洪水事件的选取则反映了近数十年来实际观测到的洪水事件特征。