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Accueil du site → Doctorat → Espagne → 2007 → HYDROMETEOROLOGICAL NUMERICAL SIMULATIONS OF WESTERN MEDITERRANEAN SEVERE PRECIPITATIONS EVENTS

Universidad ILLES BALEARS (2007)

HYDROMETEOROLOGICAL NUMERICAL SIMULATIONS OF WESTERN MEDITERRANEAN SEVERE PRECIPITATIONS EVENTS

Amengual Pou, Arnau

Titre : HYDROMETEOROLOGICAL NUMERICAL SIMULATIONS OF WESTERN MEDITERRANEAN SEVERE PRECIPITATIONS EVENTS

Auteur : Amengual Pou, Arnau

Université de soutenance : Universidad ILLES BALEARS

Grade : Tesis Doctorales 2007

Objectifs
The general motivation of our research is the development of new understanding about those environmental problems of the Western Mediterranean area –and more concretely, the Spanish Mediterranean region– that have been described in sections 1.3 and 1.4. In section 1.3, the impact of intense precipitation events over three Mediterranean catchments of different sizes (ranging, roughly, from 600 to 5000 km2) and resulting in hazardous flood episodes has been analysed. Then, a major issue for the present research has been to gain insight the hydrometeorological modeling factors which can lead to an enhancement in the study and forecasting of such flood events. The feasibility of runoff simulations driven by numerical weather prediction mesoscale models over these basins has been assessed in an attempt to further extend the lead times for warning and emergency procedures before flood situations. The inaccuracies found in the mesoscale models to the small-scale features of the quantitative precipitation forecasts have also been addressed through different approximations such as : (i) by introducing small shifts and variations of intensity of the precursor upper-level synoptic scale trough ; (ii) by using different formulations of the physical processes (i.e. cloud microphysics, moist convection and boundary layer schemes) included within the mesoscale models and (iii) by using different limited area model initializations and configurations. These issues are aimed to take into account the impact of diverse external-scale uncertainties found, nowadays, in the NWP models. With this methodology, it is possible to assess the effects due to relatively moderate spatial and temporal errors of the QPFs on the hydrological responses. In section 1.4, it has been highlighted that precipitation is undoubtedly the most critical variable in terms of present and future social and economic impacts for the Mediterranean area. Its scarcity during the summer months along with the increasing touristic activity is reflected in strong stress on the water resources, especially after abnormally dry years. On the other hand, extreme precipitation events are common in the region and damaging flash- flood events occur virtually every year. Therefore, it is also important to gain knowledge in the dynamical downscaling of precipitation from General to Regional Climate Models –as the fundamental previous step to the one-way coupling between meteorological and hydrological models– focussed on climate simulation and future climate change assessment. Hence, this issue has been examined in terms of its sensitivity to the spatial and temporal resolution of GCM input fields over the Spanish Mediterranean –a highly vulnerable region according to most of the climate change precipitation scenarios (Meteorological Office, 2001 ; Watson and Zinyowera, 2001)-

Mots Clés : SIMULACION, PRECIPITACION, FISICA DE LA PRECIPITACION, FISICA

Présentation (DIALNET)

Page publiée le 4 avril 2010, mise à jour le 19 février 2019