Speciation and origin o particulate copper in runoff water rom a Mediterranean vineyard catchment Fungicide treatments have led to large copper contents of the topsoils of most vineyards. This paper examines the contamination of surface waters by copper in a Mediterranean wine-growing catchment. Its aims were to characterise the forms of copper associatedwith suspended matter during a heavy autumn storm event and to identify which soils contribute the most to the copper exports. 1. IntroductionCopper has been used to protect vines against fungus disease since the end o the eighteenth century ( affor-gue,1928). Even today, a high proportion of ungicidesare in the form of copper compounds. It is known that such inputs tend to accumulate in the surface layers of the soil, and in turn the topsoils of most vineyards contain large amounts of copper (Flores Velez, 1996).However, copper is only partially trapped in the surface horizons since many vineyards are subject to water erosion phenomena (Vogt et al., 1986; itzler et al., 1988). These can wash the copper to downstream crops or ecosystems. Depending on the speciation of copper in runoff water, the downstream physicochemical conditions (organic complexants, pH, ionic strength, etc.) are likely to favour its solubilisation (Serpaudetal., 1994; Dawson and Macklin, 1998), and thereby its toxicity. It is therefore of interest to characterise the speciation o copper transported by runoff water leaving areas with highly contaminated soils. This is especially the case in south France which presents the largest vineyard area in the world and a Mediterranean rain all regime leading to intense sur ace runoff and erosion processes (Gomer, 1994; Albaladejo et al., 1995). Besides, it must be pointed out that copper seems to be predominantly transported by suspended matter in runoff water (e.g. Gilbin et al., 2000; Xue et al., 2000), which can be related to the affinity of copper or sorption on som...
