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.本批地图的编制旨在履行苏格兰环境保护局（Scottish Environment Protection Agency，简称SEPA）根据《2009年洪水风险管理（苏格兰）法案》所承担的发布洪水风险地图的法定职责。本系列地图展示了沿海、河流及地表积水引发的洪水风险分布区域。 针对河流洪水，提供以下不同概率等级的风险场景： - 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，以及采用英国气候预估2009（UKCP09）2080年代高排放情景的200年一遇重现期叠加气候变化影响的场景。 河流洪水风险地图（如可获取）将展示以下信息： - 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基于英国气候预估2009（UKCP09）针对2080年高排放情景下的95%分位数预测结果设定。流速信息仅在适宜场景下予以展示，其判定依据为输入数据可信度、建模方法及影响评估结果，当前流速被划分为四个等级之一。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基于近数十年间已观测到的实际洪水事件特征。