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（return period） - 中概率：200年一遇重现期（return period） - 低概率：200年一遇重现期（return period）叠加2080年代英国气候投影2009（UKCP09）高排放情景下的气候变化影响 本次地表洪水风险图（若可获取）包含以下内容： - 淹没范围（flood extent） - 淹没深度（flood depth） - 适宜场景下的洪水流速（flood velocities） 流速信息仅在适宜场景下予以展示，其判定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区间。 本数据集采用的气候变化情景，源自英国气候投影2009（UKCP09）针对2080年高排放情景给出的95%分位预测值。 本次选取中、低概率洪水事件，旨在契合苏格兰规划政策（Scottish Planning Policy）中所采用的重现期标准；而高概率洪水事件的选取，则基于近数十年来实际观测到的洪水事件特征。