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.本次公开的地表积水洪涝（surface water flooding）概率分级如下： - 高概率：重现期为10年 - 中概率：重现期为200年 - 低概率：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的200年一遇重现期事件 地表积水洪涝灾害地图（若有可用数据）将展示以下内容： - 淹没范围 - 淹没水深 - 适宜场景下的洪水流速 流速信息将在适宜场景下予以展示；是否展示流速需综合考量输入数据可信度、建模方法与影响评估结果，当前流速分为四个等级进行表征。 本次设定的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%分位数的预测结果。中、低概率洪涝事件的选取标准与苏格兰规划政策中采用的重现期要求保持一致，而高概率事件的选取则参考了近数十年间实际观测到的洪涝事件特征。