A percentile-based approach to rainfall scenario construction for surface-water flood forecasts
A percentile-based approach to rainfall scenario construction for surface-water flood forecasts
复制标题
基于百分位数的地表水洪水预报降雨情景构建方法
DOI：
10.1002/met.1963
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发表时间：
2020
影响因子：
2.7
通讯作者：
Böing S
中科院分区：
文献类型：
--
作者：
Böing S
提出了一种根据集合预报产生合理的最坏情况降雨情景的新技术。此类情景与预测持续时间在 15 分钟到几个小时之间的局部强降雨事件的风险相关。此类降雨事件可能导致地表水（雨）洪水。由于对降雨强度、持续时间和位置的精度和准确性的要求，在几个小时以上的提前时间内对这些事件进行有用的预报具有挑战性。这里描述的技术通过使用邻域技术结合集合预测构建适当的场景来解决这些挑战。它类似于早期研究中描述的距离相关的深度持续时间分析，但它引入了基于感兴趣位置附近降雨积累的概率分布函数的额外后处理步骤。这个额外的步骤使得合理的最坏情况场景更少地依赖于网格规模的行为，并有助于生成具有一致解释的场景。该方法用于将提前时间为 6-36 小时的预测与发生在约克郡的几个案例研究的雷达数据进行比较。这些比较还引入了新技术来呈现每个地点合理的最坏情况降雨累积图。
A novel technique to produce reasonable worst‐case rainfall scenarios from ensemble forecasts is presented. This type of scenario is relevant for predicting the risk of localized, intense rainfall events with a duration between 15 min and several hours. Such rainfall events can cause surface‐water (pluvial) flooding. Producing useful forecasts of these events at lead times of more than a few hours is challenging due to the precision and accuracy in rainfall intensity, duration and location that is required. The technique described here addresses these challenges by constructing appropriate scenarios using a neighbourhood technique in combination with ensemble forecasting. It is similar to the distance‐dependent depth–duration analysis described in earlier studies, but it introduces an additional post‐processing step based on probability distribution functions of rainfall accumulation near a location of interest. This additional step makes the reasonable worst‐case scenarios less dependent on grid‐scale behaviour, and helps to generate scenarios with a consistent interpretation. The method is used to compare forecasts with a lead time of 6–36 hr to radar data for several case studies that occurred in Yorkshire. These comparisons also introduce new techniques to present maps of the reasonable worst‐case rainfall accumulation at each location.