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.本批洪水危险性地图（flood hazard maps）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》（Flood Risk Management (Scotland) Act 2009）所承担的法定发布职责。本类地图覆盖海洋、河流及地表径流三类洪水风险的影响区域。 针对河流洪水，提供以下四档概率场景： - 高概率：10年一遇重现期（return period） - 中概率：200年一遇重现期（return period） - 低概率：1000年一遇重现期（return period），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场景 河流洪水危险性地图将按需展示以下内容（如数据可获取）： - 洪水淹没范围（flood extent） - 洪水水深（flood depth） - 适宜场景下的洪水流速（flood velocities） 上述气候变化修正场景的设定依据为英国气候预测2009（UKCP09）针对2080年代高排放情景下的95百分位（95%ile）预测结果。洪水流速信息仅在符合评估标准的场景下予以展示，其判定需综合考量输入数据可靠性、建模方法合理性及影响程度，当前流速被划分为四个等级。 中、低概率洪水场景的选取标准，与苏格兰规划政策中采用的重现期规范保持一致；高概率场景的选取则贴合近数十年间已观测到的实际洪水事件特征。