OZCAR-RI OZC-R Bassin de la Rivière des Pluies - France, Réunion

The Bassin de la Rivière des Pluies is located on Réunion Island (French Overseas, Indian Ocean). This volcanic island results from the emission of basaltic products from the Réunion hotspot that initiated 65 Myrs ago with the development of the Deccan traps. Rivière des Pluies drains a watershed of 46 km2 located on the windward side of the dormant Piton des Neiges volcano, from 2276 msl to the sea shore. The Rivière des Pluies catchment is mainly composed of lava flows and breccias aged from 1.4 Ma to 200 ky. The overall watershed is made of a main canyon deeply incised in the volcano flank and a large planeze covered by the deposits of the last explosive eruptions of Piton des Neiges. The combined action of the vegetation and alteration along a strong altimetric gradient produced a wide range of soils typically ranging from 0.5 to 6 meters. Vegetation is dominated by tropical rainforest. The hydrologic regime is torrential: flow rate is characterized by abrupt variations due to tropical rains. Storms and cyclones only occur during the rainy season from december to april.