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.本次可获取的地表漫溢洪水（surface water flooding）概率等级如下： - 高概率：重现期10年 - 中概率：重现期200年 - 低概率：基于英国2009年气候预测（United Kingdom Climate Projection 2009，UKCP09）2080年代高排放情景，叠加200年一遇洪水情景的气候变化影响 地表洪水灾害地图（若可获取）将展示以下内容： - 洪水淹没范围 - 洪水水深 - 适宜场景下的洪水流速 流速信息仅在适宜场景下提供，其判定依据为输入数据可信度、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进行展示。 本次采用的气候变化情景基于英国2009年气候预测（UKCP09）针对2080年代高排放情景的95%分位数预测结果。本次选取中、低概率洪水情景，是为了与苏格兰规划政策中采用的重现期标准保持一致；而高概率情景的选取，则是为了反映近数十年间实际观测到的洪水事件特征。