River Flood Maps (FRM_FH_RIVER_VELOCITY_H)

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署（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而编制。本批地图展示了海洋、河流及地表积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年代英国高排放情景（UKCP09高排放情景）的200年一遇重现期叠加气候变化影响的结果。河流洪水危险地图将展示（如可获取）以下信息： - 洪水淹没范围 - 洪水水深 - 适宜场景下的洪水流速。本气候变化情景基于英国气候预测2009（UK Climate Projections 2009, UKCP09）针对2080年代高排放情景的95%分位数预测结果定义。流速信息仅在适宜场景下提供，其判定依据为输入数据可信度、建模方法及影响评估结果，当前分为四个等级。中、低概率洪水事件的选取参考了苏格兰规划政策中采用的重现期标准，而高概率洪水事件的选取则基于近数十年间实际观测到的洪水事件特征。