Monitoring
Cumulative precipitation samples are collected at a monthly time step. Monitoring has started in November 2018 at the Castellet sampling station (local site named Le Cas). Precipitation is sampled in a watertight plastic bottle disconnected from the atmosphere to minimize water evaporation, with a buffer plastic tube for atmospheric pressure equilibration (Palmex system). The amount of water monthly collected in the bottle is measured systematically before the storage in an amber glass vial. Two other devices complete the sampling station: an open rain gauge for daily monitoring of the precipitation, and a tipping bucket rain gauge with automatic recording. Rainfall events can also be collected at a spot sampling time step.
Le Castellet sampling station
The station is located in the plain between the Mediterranean Sea and the Sainte-Baume massif. It is located about 5 km from the sea and 7 km from the top of the Sainte Baume. Most of the precipitation comes from the sea, associated with a south or southeast wind. It allows to record the isotopic signal of the rain entering the land, with little orographic effect. Isotopic analyses (18O, 17O, 2H) are performed at CEREGE laboratory.
Cette station a été précédée d’une station de prélèvement ponctuel d’événements pluvieux entre 2012 et 2018.
This station was preceded by a spot sampling station of rain events between 2012 and 2018.
Le Castellet station is also part of the SNO Karst (National Observation Service: a network of observatories for multidisciplinary study of karst). It belongs to the limestone watersheds of basse-Provence (SE France), and is part of the Port-Miou observatory site that extends from Marseille to Toulon cities. The rainfall isotopic composition is used in a global approach to study karst hydrosystems, at the water cycle scale including measurements on groundwater and surface water.
+ SNO Karst link: https://sokarst.org/
+ link Port-Miou observatory site : https://sokarst.org/sites/port-miou/
+ lien sur site CEREGE : https://www.cerege.fr/