|TITLE||TREND ON CONVECTIVE PRECIPITATION AND FLOODS IN THE SPANISH MEDITERRANEAN REGION|
|AUTHORS||MC Llasat (1), M Cortés (1), A del Moral (1), T Rigo (2), M Aznarez (1), B Aznar (3)|
- Dep. of Applied Physics, Univ. Barcelona, Barcelona, Spain
- Meteorological Service of Catalonia, Barcelona, Spain
- Barcelona Cicle de l’Aigua, SA, Barcelona, Spain
|ABSTRACT||One of the major impacts of climate change seems to be the increase of heavy precipitation, as is pointed out by the Clasius Clapeyron equation (Alexander et al, 2006). There are some works that analyses the mechanisms that could justify the increase in the precipitation intensity associated to a warmer atmosphere. Some of them justify the increase in convective precipitation as a consequence of an increase of the CAPE due to warming and moistening of the atmospheric boundary layer. Other ones say that the increasing extremes and intensity in convective precipitation may be linked to the invigoration of clouds via feedback with more water vapor that intensifies the convective process.
The aim of this presentation is to analyse the evolution of convective precipitation in the Mediterranean Spain, with a specific focus in the Metropolitan Area of Barcelona. To do this, 5-min precipitation series from 1996 to 2015 coming from more than 100 stations have been used. The intensity threshold of an average intensity of 35 mm/h in 5 min has been applied to characterize convective precipitation. Previously a regionalization has been done taking into account the precipitation characteristics. The β parameter, defined as the ratio between convective precipitation versus total precipitation in any period, has been analysed. Convective events have been related with floods (usually flash floods or surface water floods) in order to obtain any specific characteristic that could help to improve the early warning. The evolution of floods and precipitation has been analysed. Results do not show a common pattern but an increase of convective events has been detected in a wide region. Non climate factors that can affect the flood trend evolution have been also considered.|