Surface Water Flood Maps (FRM_FH_SURFACE_WATER_VELOCITY_H)

The following probabilities are available for surface water flooding: - High - 10 year return period - Medium - 200 year return period - Low - 200 year return period plus climate change using the UKCP09 high emissions scenario for the 2080s.The surface water hazard maps show (where available): - Flood extent - Flood depth - Flood velocities where appropriate. 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 bandsThe climate change scenario has been defined by United Kingdom Climate Projection 2009 (UKCP09) predictions for 2080 high emissions 95%ile predictions. Medium 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.本次公开的地表洪水概率分级如下： - 高概率：10年一遇重现期 - 中概率：200年一遇重现期 - 低概率：200年一遇重现期叠加2080年代英国气候预测2009（UKCP09）高排放情景下的气候变化影响。 地表洪水灾害地图（现有数据支撑条件下）展示以下内容： - 淹没范围 - 淹没水深 - 必要且可行时展示洪水流速。流速的展示需结合输入数据可信度、建模方法与影响评估综合判定，当前流速被划分为四个等级之一。 本次采用的气候变化情景基于英国气候预测2009（UKCP09）针对2080年高排放情景下的95%分位数预测结果设定。 本次选取中、低概率洪水事件，以匹配苏格兰规划政策中采用的重现期标准；高概率洪水事件的选取则基于近数十年来已观测到的实际洪水事件特征。