Intermittent river

Intermittent (or temporary) rivers cease to flow every year or at least twice every five years(Tzoraki and Nikolaidis 2007). Such rivers drain large arid and semi-arid areas covering approximately a third of the world’s surface (Thornes, 1977). The extent of temporary rivers is increasing, as many formerly perennial rivers are becoming temporary because of increasing water demand, particularly for irrigation (De Girolamo, Calabrese et al. 2012). The combination of dry crusted soils to the high intensity and erosivity energy of the rain cause sediment resuspension and transport to the coastal areas (Tzoraki, Nikolaidis et al. 2009). They are among the aquatic habitats most altered by human activities (Moyle 2013). During the summer even under no flow conditions the point sources are still active such as the wastewater effluents (Perrin and Tournoud 2009; Chahinian, Bancon-Montigny et al. 2013) resulting in nutrients and organic pollutants accumulation into the sediment. Sediment operates as a pollution inventory and pollutants are moved to the next basin with the first flush (Bernal, von Schiller et al. 2013). Their vulnerability is intensified by the conflict between water use demand and aquatic ecosystem conservation (Webb, Nichols et al. 2012). Advanced modelling tools have been develobed to better describe intermittent flow dynamic changes such as tempQsim model (Tzoraki et al., 2009).

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