|
Ecosistemes de Catalunya A. Curcó. Aiguamolls
litorals: el Delta de l'Ebre. Síntesi del medi físic d’una zona
humida litoral. The Ebre delta, with an area of 330 km2 and located in the south of Catalonia, shapes a formidable example of coastal wetland. In this work we carry out a synthesis essay on the physical environment components: geographic physiognomy, geology (evolution and sedimentary environments), topography, soils, hydrology (superficial and underground waters) and climate. In spite of showing a quite flat topography, with slopes in the order of 0.01-0.02%, the Ebre delta shows a high heterogeneity in relation of environments and sedimentary, edaphic and hydrological processes. The confluence of contrasted dynamics (riverine, marine and underground) explain most of this high spatial and temporal variability. However, anthropogenic impacts produced since the 19th century, which have changed most of the hydrological and sedimentary balances (sediments retention by dams, riverine flow decrease, hydrological fluxes modifications, etc.) have strongly modified the pristine dynamics. Soil elevation loss, product of fluvial sediments drop, as well as the subsidence, makes in danger the physical, environmental and socioeconomic sustainability of the delta. This fact will worsen in the future since the sea level rise produced by the global warming. |
|
