'El Gergal' ReservoIR
'El Gergal' is a is a medium size reservoir located in the catchment of the Rivera de Huelva River, a tributary of the Guadalquivir River on the Atlantic coast of Andalucía (Southern Iberian Peninsula). The surface area of the reservoir is 250 ha, the volume is 35 hm³ and maximum depth of 37 m. This reservoir is equipped with high frequency monitoring system (HFM) which perform vertical profiles, several times at day, measuring physico-chemical and biological variables . In addition, Empresa metropolitana de Abastecimiento y Saneamiento de Aguas de Sevilla (EMASESA) has been carry on periodical biological sampling and analysis from 70's. Thus, this reservoir has been widely studied and provide a comprehensive source of data.