River Flood Maps (FRM_FH_RIVER_VELOCITY_DIRECTION_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.本批地图的制作旨在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案》所规定的发布洪水危险地图的义务。本地图展示了海洋、河流及地表积水引发的洪水风险区域。 针对河流洪水，本次提供以下不同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，以及基于英国气候预测2009（UKCP09）2080年代高排放情景模拟得到的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（如可获取的情况下）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。洪水流速将在适宜场景下予以展示，其展示与否及分级标准需综合考虑输入数据可靠性、建模方法及影响效果，当前流速分为四个等级。本次选取中、低概率洪水事件的重现期标准，以与苏格兰规划政策中采用的重现期规范保持一致；而高概率洪水事件的选取标准，则反映了近数十年来观测到的实际洪水事件特征。