Evaluation of pesticides contents in cultivated soils in the Roujan catchment area.

The evaluation of soil moisture in different areas of the Roujan catchment area is carried out by measuring the moisture content of fresh soil samples.

A flow tower is installed on the watershed of Roujan as well as a meteorological station of the AgroClim service unit (INRAE). At these points a set of sensors are arranged in order to collect various meteorological variables such as wind speed, air humidity and temperature, global radiation or evapotranspiration. Just like the other measurements made on the basin by sensors, data acquisition units record the values which are transmitted several times a day to our servers at the INRAE centre in Montpellier or retrieved via Agroclim's webservice. R routines are then used to process these data and prepare them for integration into the HYSAE database of the LISAH, thus integrating them into the information system for OMERE. Through the OMERE data web portal, the address of which is given in this fact sheet, the data can be consulted and downloaded.

The rainfall of the Roujan (Hérault) catchment area has been acquired since 1992 through various measuring points on which sensors are positioned on a long-term and continuous basis. The data from these sensors are directly recorded on servers in Montpellier through remote transmission. Verification treatments and possible corrections are applied before the data sets are integrated into the HYSAE database. Through the OMERE data portal accessible from this sheet, the data can be downloaded from an interactive map. In addition to these raw data rainfall records, a so-called "synthetic" time serie is elaborated to provide a complete and uninterrupted chronicle of rainfall data representative for the catchment area.

Pesticide contents are determined on the suspended matter extracted by filtration (0,7µm) in runoff water. Contents allow quantification of particula transport of pesticides and allow too compare it to solute transport.

water samples ( rain, runoff, underground water) are carried in icebox and frozen. ( FILTRATION ? ). Samples are analyzed by a dedicated laboratory, that quantify a set of parameters including from 1 to 430 pesticide active ingredients and their metabolites.