2DVD Data Revisited: Multifractal Insights into Cuts of the Spatiotemporal Rainfall Process
2DVD Data Revisited: Multifractal Insights into Cuts of the Spatiotemporal Rainfall Process
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2DVD 数据重温：时空降雨过程切割的多重分形见解
DOI：
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发表时间：
2015
期刊：
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通讯作者：
A. Berne
中科院分区：
文献类型：
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作者：
A. Gires;I. Tchiguirinskaia;D. Schertzer;A. Berne
本文利用法国阿尔德切地区发生的四次暴雨过程中收集的资料，利用2DVD视频仪对雨滴的时空分布结构进行了研究。第一类分析基于测量装置上方36米高的垂直降雨柱的重建。这种重建是在1ms时间步长序列的弹道假设的帮助下获得的。利用泛多重分形学对相应的快照进行了分析。为了比较，对具有1ms时间步长的时间序列以及对N个连续记录的液滴的累积图的时间序列执行类似的分析(因此具有可变的时间步长)。结果表明，在地震最重的部分，液滴分布在0.5-36m的范围内表现出良好的标度行为，证实了广泛使用的液滴分布的均匀假设缺乏经验证据。对于较小的尺度，下跌位置似乎是均匀分布的。极高分辨率的时间序列很好地说明了多重分形点的概念。
Data collected during four heavy rainfall events that occurred in Ardeche (France) with the help of a 2D video disdrometer (2DVD) are used to investigate the structure of the raindrop distribution in both space and time. A first type of analysis is based on the reconstruction of 36-m-height vertical rainfall columns above the measuring device. This reconstruction is obtained with the help of a ballistic hypothesis applied to 1-ms time step series. The corresponding snapshots are analyzed with the help of universal multifractals. For comparison, a similar analysis is performed on the time series with 1-ms time steps, as well as on time series of accumulation maps of N consecutive recorded drops (therefore with variable time steps). It turns out that the drop distribution exhibits a good scaling behavior in the range 0.5-36 m during the heaviest portion of the events, confirming the lack of empirical evidence of the widely used homogenous assumption for drop distribution. For smaller scales, drop positions seem to be homogeneously distributed. The notion of multifractal singularity is well illustrated by the very high-resolution time series.