GABELLONE Nestor Adrian
THE EFFECTS OF HYDRAULIC WORKS AND WETLANDS FUNCTION IN THE SALADO-RIVER BASIN (BUENOS AIRES, ARGENTINA)
BAZZURI, MARÍA ELISA; GABELLONE, N A; SOLARI, LÍA CRISTINA
ENVIRONMENTAL MONITORING AND ASSESSMENT
Lugar: Berlin; Año: 2018
Man-made activities exert great influences on fluvial ecosystems, with lowland rivers being substantially modified through agricultural-land use and populations. The Salado River is located in the Argentine pampas, and drains one of the country?s most productive areas though flooding often threatens the basin. The recent construction of drainage canals in the upper stretch caused the mobilization of huge amounts of salts, formerly stored in the groundwater. The main aim of this work was to analyze the effect of the discharges of those canals into the Salado-River water, under different hydrologic conditions, and the role of the wetlands and shallow lakes placed along the canals? system. For this purpose, we measured physicochemical variables and took water samples during times of high water, mean flows,drought, and extreme drought. The environmental variables were related to the hydrologic regime and reachedminimum values during floods because of low temperatures and dilution. Local effects on the water?s ionic composition became pronounced during droughts due to groundwater?s inputs. Nutrient concentrations were mainly associated withpoint wastewater discharges. Conductivity and ion concentrations increased in the Salado-River downstream site, after the canals? discharges. The artificial-drainage system definitely promotes the incorporation of salts into the Salado-River basin. In this scenario, a careful hydraulic management is needed to take into account this issue of secondary salinization that threatens the economic exploitation of the region. The wetlands present in this study acted as serviceenvironments; helping to reduce salt, nutrient and suspended-solid concentrations downstream.