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.本次可获取的地表积水泛滥（surface water flooding）概率分级如下： - 高概率：10年一遇重现期 - 中概率：200年一遇重现期 - 低概率：基于2080年代英国2009年气候预估（United Kingdom Climate Projection 2009，UKCP09）高排放情景下气候变化影响的200年一遇重现期事件。 本次地表积水泛滥风险地图可在数据可用时展示以下内容： - 淹没范围 - 淹没水深 - 适宜场景下的洪水流速。洪水流速仅在满足条件时予以展示：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，当前流速被划分为四个等级之一。 本次采用的气候变化情景，基于英国2009年气候预估（UKCP09）针对2080年高排放情景下的95%分位数预测结果设定。中、低概率洪水事件的选取依据《苏格兰规划政策》中采用的重现期标准，以保障标准一致性；高概率事件的选取则参考了近数十年间实际观测到的洪水事件特征。