The Observatory of Water and Erosion in the West Indies (ObsERA) is an observation service of the INSU-CNRS and the Paris Institute of Physics of the Earth (IPGP) devoted to the study of Erosion and erosion in the West Indies. Member of the Network of Research Watersheds and the Critical Zone Observatory Network, it involves teams from the IPGP, the Volcanological and Seismological Observatory of Guadeloupe, the University of Antilles-Guyane, the European University Institute of Mer (UBO) and the Laboratory of Earth Sciences of the University Claude Bernard (Lyon I).
Topical zones, characterized by very irregular hydrological regimes in which extreme weather events play an important role, are particularly sensitive to any environmental change: climate change, changes in rainfall acidity, increase in anthropogenic pressure associated with Population growth, etc ... It is this observation that led to the establishment of the Observatory of water and erosion in the West Indies (ObsErA).
The objective of ObsErA, which has been labeled the Observational Service of INSU since January 2011, is to allow the creation of a database of water flows (precipitation and flow of rivers), sediment and organic matter (especially carbon) in rivers and on slopes, as well as the chemical composition of rivers and soils in the particular context of the island of Basse-Terre, marked by a tropical climate and active volcanism. This database will enable the scientific community to study and quantify the methods of chemical and physical denudation, their coupling and their impact on the environment (soil composition, river chemistry, carbon flux, etc.).
ObsErA also aims to develop new techniques for measuring river transport and slope dynamics as well as new tracing methods (isotopic in particular) adapted to characterize the dynamics of ecosystems.
Two catchments are regularly monitored: Bras-David and Capesterre. A third watershed, Vieux-Habitants, serves as a test site for the development of an aerial imagery technique using a drone.
The Bras-David river is located on Basse-Terre Island (Guadeloupe archipelago, lesser Antilles arc)