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.本次地表洪水灾害具备如下概率等级： - 高概率：重现期为10年一遇 - 中概率：重现期为200年一遇 - 低概率：叠加2080年代英国2009年气候预测（UKCP09）高排放情景下气候变化影响的200年一遇洪水 地表洪水灾害地图（若有提供）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。流速是否展示需结合输入数据可信度、建模方法与影响评估综合判定，当前流速分为四个等级进行呈现。 本研究所采用的气候变化情景，基于英国2009年气候预测（UKCP09）中2080年高排放情景的95%分位预测值设定。本次研究选取中、低概率洪水事件，以匹配苏格兰规划政策中采用的重现期标准；而高概率洪水事件的选取则参考了近数十年间实际观测到的洪水灾情。