Resumen de Influencia de las descargas de los asentamientos urbanos sobre el Río Uruguay entre los años 1998 y 2004
Constanza Gabriela Llorente, Daniel Atilio Molina, Pablo Alejandro Zorzoli, Alejandra Volpedo
- español
El Río Uruguay integra junto con el Paraná y el Paraguay la Cuenca del Plata; recorriendo aproximadamente unos 1700 Km desde su naciente en la Sierra do Mar (Brasil) hasta su desembocadura en el Río de la Plata. En el trayecto correspondiente a su cuenca baja (desde la línea imaginaria Bella Unión – Monte Caseros), sirve como límite internacional entre la República Argentina y la República Oriental del Uruguay, zona que es administrada por la Comisión Administradora del Río Uruguay (CARU).
Sobre las márgenes del Río se encuentran asentamientos urbanos importantes como Concordia, Colón, Concepción del Uruguay y Gualeguaychú de la margen Argentino y Salto, Paysandú y Fray Bentos de la margen Uruguaya; estos asentamientos presentan importantes desarrollos agrícolas e industriales con descarga directa al río. En este trabajo analizaremos la influencia de estas descargas sobre el Río Uruguay en el periodo 1998-2004.
- English
Uruguay river is 1800 km long and its basin covers an area of 339000 km2. It is the international border between Argentina and Uruguay in its last 508 km along which seven cities are settled. From north to south Concordia, Colón, Concepción del Uruguay and Gualeguaychú are located on the Argentinian margin whereas Salto, Paysandú and Fray Bentos are on the Uruguayan margin. These cities have greatly developed in the last 50 years. However, their influence on Uruguay River has not been studied.This work was aimed at analyzing the impact of these discharges on the Uruguay River during the period 1998-2004 and at comparing the physicochemical values and biological parameters based on the levels proposed by the Administrative Commission of the Uruguay River (CARU, in Spanish) and the baseline of the main channel. Data from 12 winter or spring campaigns were gathered. The following physicochemical parameters were measured: conductivity, pH, dissolved oxygen, alkalinity, hardness, total dissolved solids, nitrates, nitrites, ammoniums, phosphates, major ions (Na+, K+; Ca2+, Mg2+, Cl-, SO42-) and metals (Cd2+, Cc2+, Cr3+ y Pb2+). Fecal coliform bacteria were considered to be a biological parameter. All these parameters were analyzed by applying standard methods. The results showed that the seven cities on Uruguay River banks produce different effects on the quality of its coastal waters. The sampling sites at Concordia in Argentina and Paysandú in Uruguay showed values higher than those recommended by the CARU to ensure water quality for public consumption with a conventional treatment. It is noteworthy that, although an important influence of the discharge of the seven cities on the river is observed, it is moderate due to its self-purifying capacity.
