River Flood Maps (FRM_FH_RIVER_VELOCITY_DIRECTION_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.本批洪水危险性地图是为履行苏格兰环境保护局（Scottish Environment Protection Agency，SEPA）依据2009年《苏格兰洪水风险管理法》所规定的发布洪水危险性地图的法定职责而制作的。 该类地图展示了受海洋、河流及地表水引发的洪水风险的区域。 针对河流洪水，提供以下不同概率等级的洪水风险场景： - 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，以及基于英国气候预测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。 河流危险性地图将（在数据可用的情况下）展示以下内容： - 洪水淹没范围 - 洪水水深 - 适宜场景下的洪水流速。 本数据集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95百分位预测结果。洪水流速仅在适宜场景下予以展示，其展示与否取决于对输入数据、建模方法及影响评估的置信度，当前流速被划分为四个等级之一。 中、低概率洪水场景的选取是为了与苏格兰规划政策中采用的重现期标准保持一致，而高概率场景的选取则是为了反映近几十年来实际观测到的洪水事件特征。