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.本数据集提供地表洪涝（surface water flooding）的概率分级信息如下： - 高概率：对应10年一遇重现期（return period） - 中概率：对应200年一遇重现期 - 低概率：对应200年一遇重现期叠加2080年代采用英国气候预测2009（UKCP09）高排放情景的气候变化影响 地表洪涝灾害风险图（surface water hazard maps）将包含以下内容（如可获取）： - 淹没范围（Flood extent） - 淹没水深（Flood depth） - 适宜场景下的洪水流速（Flood velocities） 洪水流速的呈现需结合输入数据可信度、建模方法与影响评估进行判定，目前将其划分为四个等级之一。 本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95%分位数预测值的结果定义。 本次选取中、低概率洪涝事件，以匹配《苏格兰规划政策》中采用的重现期标准；而高概率事件的选取则反映了近数十年间观测到的实际洪涝事件特征。