Programme Poster session 2 abstract 523
Atmospheric input of contaminants to a small Mediterranean basin
Author(s): C. Salles, N. Rico-Caicedo, J.L. Seidel, B.Picot, M.G.Tournoud
Université Montpellier II - HYDROSCIENCES (UMR 5569 CNRS-IRD-UM2-UM1), F-
34095 Montpellier Cedex 5, France
Keyword(s): precipitations, nutrient deposition, trace elements, wet and
bulk deposition, deposition rate
Session: Poster session 2
Abstract Rainwater chemistry was monitored during a two years period (Nov.
2003 – Oct. 2005) for quantification of the atmospheric input over a small (70 km2) rural Mediterranean watershed.
A refrigerated wet-only precipitation collector with a nearby bulk sampler were installed at one station. Two more
bulk samplers were installed, near the top of the basin and close to the basin outlet. Major element contents (HCO3,
Cl, NO3, SO4, Ca, Mg, Na, and K) were determined by Ion Chromatography, nutrients content (PO43-, NO3-
,NO2- and NH4+) determined following APHA standard and trace element contents (Al, B, Ba, Cd, Cr, Cu, Co,
Li, Mn, Mo, Ni, Pb, Rb, Sr, U, V and Zn) by ICP-MS. During the observation period, a total of 83 rain samples
were collected and analyzed for wet and dry deposits determination.
The dataset obtained from the field study is
presented and discussed. The primary objectives were i) to compare wet and bulk deposition, ii) to evaluate the
temporal and spatial variation in rainwater for contaminants, and iii) to estimate the annual atmospheric input to the
basin, derived from natural or anthropogenic origins and to identify potential pollution from rain.
Finally, the
possible origins and the main factors affecting the concentrations of the measured species are discussed. The
estimation of the precipitation inputs is a part of the diagnostic study of the chemical and microbiological fluxes
contribution of the watershed to the Thau lagoon.