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.针对地表洪水（surface water flooding），可获取以下按概率分级的情景： - 高概率：10年一遇重现期 - 中概率：200年一遇重现期 - 低概率：2080年代采用英国气候预测2009（UKCP09）高排放情景下，叠加气候变化影响的200年一遇情景 地表洪水灾害风险图可展示（若数据可用）以下内容： - 淹没范围 - 淹没水深 - 适宜场景下的洪水流速。流速的展示需结合输入数据可信度、建模方法及影响效应综合判定，当前将流速划分为四个等级进行呈现。 本研究采用的气候变化情景，基于英国气候预测2009（UKCP09）针对2080年代高排放情景下的95%分位数预测结果定义。中、低概率洪水情景的选取参考了苏格兰规划政策中采用的重现期标准，而高概率情景的选取则贴合近数十年间实际观测到的洪水事件特征。