Surface Water Flood Maps (FRM_FH_SURFACE_WATER_VELOCITY_L)

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.本次公开的地表洪水（surface water flooding）概率等级如下： - 高概率：10年一遇重现期 - 中概率：200年一遇重现期 - 低概率：采用2080年代英国气候预测2009（UKCP09）高排放情景，叠加气候变化影响的200年一遇重现期洪水事件。 地表洪水风险地图（如有提供）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。流速的展示需综合考量输入数据可信度、建模方法及影响评估结果，目前分为四个等级区间。 本次所用气候变化情景源自英国气候预测2009（UKCP09）针对2080年高排放情景下95%分位数的预测结果。中、低概率洪水情景的选取参考了苏格兰规划政策中所采用的重现期标准；高概率情景的选取则贴合近数十年来实际观测到的洪水事件特征。