The main factors inducing chemical spatial heterogeneity in the Salto Grande, a reservoir on the Uruguay River
Conde, D.; Pintos, W.; Gorga, J.; De Leon, R.; Chalar, G.; Sommaruga, R.
Saito Grande (mean flow 4640 m3/s; surface 757 km2) is a subtropical polymictic reservoir built in 1979 for power generation by damming the Uruguay River. Relevant limnological differences between the main channel and lateral arms of the reservoir were registered due to different circulation patterns. The main force driving the system was assumed to be the sharp seasonality of the hydrological cycle. Due to the dendritic shape and complex morphometry, a lacustrine-type reservoir develops during the summer, whilst a river-like system occurs in winter. Runoff from the northern area of the basin is the main source of phosphorus entering the reservoir. whereas nitrogen and silicate enter the lacustrine area of the reservoir through lateral arms receiving local runoff.