Surface Water Flood Maps (FRM_FH_SURFACE_WATER_VELOCITY_M)

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.本次公开的地表积水洪涝（Surface Water Flooding）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：2080年代采用英国气候预测2009（UKCP09）高排放情景下的200年一遇重现期叠加气候变化影响 地表积水洪涝风险图（若可获取）包含以下内容： - 洪水淹没范围 - 洪水水深 - 适情展示洪水流速。流速的展示需综合考量输入数据可信度、建模方法及影响效应进行判定，目前将流速划分为四个等级。 本次采用的气候变化情景基于英国气候预测2009（UKCP09）中2080年代高排放情景下95%分位数的预测结果。 中、低概率洪涝事件的选取遵循苏格兰规划政策中的重现期标准，而高概率事件的选取则贴合近数十年间实际观测到的洪涝事件特征。