Indices of precipitation extremes in Southern Portugal – a geostatistical approach

Abstract

Abstract. Most of the actual studies and previews of future rainfall patterns, based on past observed records for Mediterranean climate areas, focus on the decline of the rainfall amounts over the years, and also on the increase of the frequency of heavy/intense rainfall events particularly in the winter season. These changes in heavy rainfall events may have severe implications and impacts on soil erosion resulting in increased soil degradation risks.The objective of the present work is to evaluate the spatial distribution of extreme precipitation events in Southern Portugal, using a geostatistical approach to assess the relationships between spatial and temporal extreme rainfall patterns. The used dataset comprises a set of 105 stations' records of daily precipitation within the period 1960-1999. Two indices of extreme precipitation were selected to be computed based on the daily precipitation observation series: one representing the frequency of extremely heavy precipitation events (R30) and another one characterizing flood events (R5D).The space-time patterns of the precipitation indices were evaluated and simulated using a geostatistical approach. Despite no significant temporal trends were detected on the calculated indices series, the space-time decadal patterns are becoming more continuous in the last two decades than the previous ones.

A new tool for monthly precipitation analysis in Spain: MOPREDAS database (monthly precipitation trends December 1945–November 2005)

“…Finally, we noticed the recent paper by Durao et al (2009) analysing 105 stations in southern Portugal (1960Portugal ( -1999, which offers the possibility for future analysis of the entire IP.…”

Spatial and temporal variability of precipitation and drought in Portugal

“…A few of these studies refer to the Iberian Peninsula, not detailing Portuguese conditions (e.g., Rodriguez-Puebla et al, 1998;Serrano et al, 1998;Vicente-Serrano et al, 2006). Various studies were conducted for Portugal on temporal variability of precipitation using spectral analysis (Antunes et al, 2006;CorteReal et al, 1998), non-parametric trend tests (de Lima et al, 2010), or geostatistical techniques applied to precipitation extremes (Durão et al, 2009). Santos et al (2010) used PCA and cluster analysis to study the spatial patterns of droughts with the SPI at different time scales in mainland Portugal.…”

A Comparison of Bangladesh Climate Surfaces from the Geostatistical Point of View

“…The spatial interpolation techniques have been used for mapping the spatial patterns of climatic fields in several regions of the world, such as France [22], Germany [23], the UK [24], Italy [25], Mexico [26,27], Portugal [28,29], and the USA [30]. There have been a few studies conducted on the Bangladesh climate, based on the data from meteorological stations [2,21,[31][32][33][34], but so far no study has been conducted in Bangladesh on comparing the performance and prediction ability of different spatial interpolation methods to produce climate surfaces.…”