Spatial and temporal variability of the daily rainfall regime in Catalonia (northeastern Spain), 1950–2000

Abstract

Spatial and temporal patterns in the daily rainfall regime of Catalonia (northeastern Spain) recorded for the 1950-2000 period are analysed from several points of view, including the irregularity of the time series in terms of entropy, the Mann-Kendall test for time trends, a principal component analysis (PCA), an average linkage (AL) clustering algorithm and, finally, a power spectrum analysis, which includes a comparison of white-noise and Markovian red-noise hypotheses. The analyses are based on three monthly variables derived from the amounts recorded on a daily basis: the average daily rainfall and the standard deviation of the daily rainfall for each month, together with the corresponding coefficient of variation. The joint spatial-temporal variability is manifested by the irregularity index, which is characterized by relevant values in all cases and gradients from the north (Pyrenees and Pre-Pyrenees mountain ranges) to the south (Ebro Valley) and to the Mediterranean coast. The interpretation of the factor scores derived from the PCA and of the clusters obtained from the AL algorithm also describes the complex spatial distribution of the daily rainfall regime, given that the effects of atmospheric circulation patterns on rainfall regimes are conditioned by the complex orography of Catalonia and its proximity to the Mediterranean Sea. The factor loadings associated with the PCA also suggest a distinction between hot, cold and mild seasons. Finally, it is worth noting that monthly series are usually accompanied by white background noise and, in a few cases, signs of Markovian behaviour and some significant periodicities, which are generally of less than 10 months and which change from one cluster to another.

Comparative Study of Different Stochastic Weather Generators for Long-Term Climate Data Simulation

“…Thus, this period was selected for further analysis. For this study, there was no imputation done for missing data so as to minimize uncertainties that may arise in generated data due to imputed data [61].…”

Changes in the probability of extreme daily precipitation observed from 1951 to 2002 in the Iberian Peninsula

“…The analysis of daily precipitation in the Iberian Peninsula has received scarce attention, probably because of the lack of highquality daily data. The scarce studies performed at the daily scale are restricted to particular regions or localities within Spain, mainly in Catalonia and the Mediterranean watershed (De Luis et al, 2000;González-Hidalgo et al, 2003;Lana et al, 2003;Vicente-Serrano and Beguería-Portugués, 2003;Lana et al, 2004Lana et al, , 2005, and Lisbon in Portugal (Trigo et al, 2005). Studies dealing with trends in daily precipitation for the whole peninsula are even more scarce (Goodess and Jones, 2002;Martín-Vide, 2004;Rodrigo and Trigo, 2007).…”

Return period maps of dry spells for Catalonia (northeastern Spain) based on the Weibull distribution / Périodes de retour des périodes sèches en Catalogne (nord-est de l'Espagne) à partir de la distribution de Weibull

“…The homogeneity of every raingauge record and a certain lack of data for some gauges have been extensively analysed, quantified and discussed by Lana et al (2004) and Burgueño et al (2005), who have used the same database to investigate different patterns of the daily rainfall regime. Figure 1 depicts the main orographic features of Catalonia and Fig.…”

“…It is well known that the rainfall regime of Catalonia is governed by the synoptic circulation, its complex orography and its vicinity to the Mediterranean Sea (Serra et al, 1998;Sotillo et al, 2003;Lana et al, 2004). These facts, together with the time irregularity of the Mediterranean climate (Barry & Chorley, 2003), generate a set of complex patterns of the rainfall regime that makes an analysis of the drought phenomena relatively difficult, especially if attention is focused on dry spell lengths derived from daily data.…”