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.下述为可获取的地表洪水概率等级： - 高概率：10年一遇重现期 - 中概率：200年一遇重现期 - 低概率：200年一遇重现期叠加气候变化情景，该情景采用英国气候预测2009（UKCP09）高排放场景下2080年代的预测数据。 地表洪水灾害地图将包含（如可获取时）以下信息： - 洪水淹没范围 - 洪水水深 - 适宜场景下的洪水流速。流速的呈现需结合输入数据的可信度、建模方法与影响效应进行判定，目前将其划分为四个等级之一。 本气候变化情景依据英国气候预测2009（UKCP09）针对2080年高排放情景下95%分位数的预测结果定义。本次选取中、低概率洪水事件以匹配苏格兰规划政策（Scottish Planning Policy）中采用的重现期标准；而高概率洪水事件的选取则旨在反映近数十年间已观测到的实际洪水事件特征。