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.本次地表积水洪涝数据集包含以下概率分级： - 高概率：对应10年一遇重现期 - 中概率：对应200年一遇重现期 - 低概率：对应2080年代采用英国气候预估2009（UKCP09）高排放情景的200年一遇重现期叠加气候变化影响 地表洪涝致灾因子分布图可展示以下内容（如数据可获取）： - 淹没范围 - 淹没水深 - 适宜场景下的洪水流速。流速的呈现需结合输入数据可信度、建模方法与影响效应进行判定，当前将流速划分为4个等级之一。 本次采用的气候变化情景基于英国气候预估2009（UKCP09）针对2080年代高排放情景的95百分位预测结果。中、低概率洪涝事件的选取与苏格兰规划政策中采用的重现期标准保持一致，而高概率事件的选取则参考了近数十年来已观测到的实际洪涝事件特征。