Impact of significant floods on the annual load in an agricultural catchment in the mediterranean

SummaryThe purpose of this study is to investigate the characteristics of the annual distribution of pollutant loadings and flush pulses caused by accumulation downstream of point source inflows in the agricultural catchment of the Vène at the Mediterranean French coast. On the basis of the period from October 2002 to October 2004, flow, rainfall and quality parameters such as total suspended solids (TSS), volatile suspended solids (VSS), total phosphorus (TP), soluble reactive phosphorus (SRP), total nitrogen (TN), organic nitrogen (org-N), nitrate and nitrite–nitrogen (NOX–N) and ammonium–nitrogen (NH4–N) were analyzed. The measurements were compared by means of normalized cumulative loadings against normalized cumulative flow and the calculation of relative mass fluxes as the ratio of cumulative load to cumulative flow for an annual scale. The results show strongly varying transport activity with an increased intensity in the beginning of the flow period especially for particulate materials.