CBL - Campus del Baix Llobregat

Projecte llegit

Títol: Sinoptic study of flood events in the northeast of the Iberian Peninsula during the last 150 years

Estudiants que han llegit aquest projecte:

Director/a: PINO GONZÁLEZ, DAVID

Departament: FIS

Títol: Sinoptic study of flood events in the northeast of the Iberian Peninsula during the last 150 years

Data inici oferta: 28-01-2015     Data finalització oferta: 28-09-2015


Estudis d'assignació del projecte:
    Tipus: Individual
     
    Lloc de realització: EETAC
     
    Segon director/a (UPC): MAZÓN BUESO, JORDI
     
    Paraules clau:
    floods, meteorology, hydrology, Catalonia, Mediterranean, natural hazards, history, synoptic study, convective indices, stability, peak flow, CAPE
     
    Descripció del contingut i pla d'activitats:
    Flash floods in small catchments are the most deadly natural hazard in Spain but, nevertheless, one of the most unknown. PREDIFLOOD project is an innovative and deep study of these extreme meteorological and hydrological processes through the analysis of the most important events recorded in NE Spain in the last 500 years (1500-2012).

    The study and forecast of flash floods are difficult because they are short-lived, occur irregularly in time and affect small areas, due to which, scarce information is available, and only in some areas and for recent years. Studies so far are limited to a few cases occurred in the second half of the 20th century. The methodology proposed in this project to fill this lack of information is a multidisciplinary approach, which will gather meteorology, hydrology, hydraulics and history. Thus, it will allow an integral analysis of flash floods, with measured and proxy data. The combination of various methods (already tested in the international literature) is required due to the complexity of the studied phenomena and it will imply a multidisciplinary collaboration with new methodological procedures and it will produce an amount of information only matched by some European research groups.

    The results of the reconstruction will be used in a classification of flash floods according to causes, magnitud, affected area, frequency, hydrological response, flow regimes, previous atmospheric scenarios and damages.

    The present project is related with the meteorological study of the flash floods.


    The student, by using MATLAB scripts, will analyze the synoptic situation that occurred during the most severe and relatively well-reported flash floods in the last 150 years. He/She will classify the different events according to the main synoptic configurations of the atmosphere and its stability indexes, in order to determine what are the most important causes that produce this type of precipitation in the Northeast of the Iberian Peninsula.
     
    Overview (resum en anglès):
    Floods are the main natural hazards affecting the population worldwide. The Western Mediterranean region is one of the areas in risk of suffering these phenomena. In this region, these types of events have lead in many occasions to the destruction of infrastructures and agriculture terrains, and hundreds of human fatalities. A wide research of historical, hydraulical, hydrological and meteorological factors that affected during these events is needed, in order to be able to predict these hazards in the future. We have focused our study in the meteorological reconstruction of these historical floods.

    By using the ‘Prediflood’ database we have selected the 23 most catastrophic floods that affected the Northeast of the Iberian Peninsula between 1874 and 2000. Then, the NOAA 6 hourly 20th Century V2 Reanalysis Data Composites have been used in order to analyze the synoptic conditions along each flood and several convective indices of the atmosphere.

    As a result, after studying these 23 floods, we have found a strong correlation between the stability indices and the season in which the flood occurred. For example the Convective Available Potential Energy (CAPE) usually presents high values during summer episodes, moderate during autumn and low values in winter floods. Regarding the duration of the rainfall, autumn and summer events are usually generated by shorter rainfalls than winter ones.

    Then, we have focused on studying deeply the synoptic conditions and the temporal evolution of the convective indices for 5 episodes that can be representative of all the rest in terms of stability conditions.

    Moreover, studying the hydrological data available for these events, there are clear differences between floods which affected mainly the coast and those which affected the Pyrenees. Coastal specific peak flows are larger than the Pyrenean ones, especially for small catchment areas.

    In addition, we have related meteorological (rainfall duration, CAPE), hydrological (specific peak flow) and geomorphological (catchment area) data to show dependencies between them and between the region (Coast or the Pyrenees) and the season when occurred the flood. Large values of CAPE are usually associated to large specific flows.

    © CBLTIC Campus del Baix Llobregat - UPC