Modélisation des longueurs des périodes sans pluies supérieures à différents seuils de la chronique de Marseille (1864-2008)

Physio-Géo

关键词: Mediterranean;    climate;    drought;    dry spell;    ESTOUP-ZIPF model;    Marseille;   

DOI  :  10.4000/physio-geo.4805

来源: DOAJ

【 摘 要 】

Every drought begins with periods without rainfall combined with low precipitation. With the Marseille daily chronic (1864-2008), we show that the statistics of these periods without rain above different steps fits a particular distribution, whatever the chosen threshold (0, 1, 3… mm).The histograms show that the number of longer periods "without rain" is quite low. This also appears, for high thresholds, when one adjusts the model ESTOUP-ZIPF, extended by B. MANDELBROT, to all data. At this stage it is not possible to know if this problem depends on a sampling problem, or if it corresponds to a structural dimension of rainfall field in Marseille (coastal position and influence of the sea).The shift (Δ parameter) introduced by B. MANDELBROT in the model of ESTOUP-ZIPF (and its variation according to thresholds) characterizes any distribution whose the short periods without rain above different thresholds. The slope of this model measures the overall importance of the hierarchy of lengths of periods without rain.

【 授权许可】

Unknown