A spatially explicit framework to assess human impacts on water quality in the Chubut River Watershed, Patagonia, Argentina

LIBEROFF, ANA LAURA

Viena

Taller; Second research coordination meeting; 2016

The increase in development and in the consumptive use of water has resulted in the deterioration of the health of freshwater ecosystems worldwide. The Chubut River watershed is the third more extensive watershed in Patagonia, Argentina (53.800 km2) and the second most populated (210.000 people), yet it is amongst the smallest rivers in the region in terms of discharge (51m3 sec-1). It supports a wide variety of human activities including agriculture, cattle-ranching, hydropower production and urban sprawl. The Laboratory Ecofluvial (CENPAT-CONICET, Puerto Madryn) is participating in this CRP in order to evaluate stable isotopes as tracers of human impacts on water quality in the Chubut watershed. A preliminary analysis indicated that water quality of the Chubut river is affected by agriculture, urbanization and desertification. Addition of fertilizers, livestock waste, sewage and sediment-bound transport might be the main causes of water contamination. d15N of particulated organic matter raised as a potential indicator of increased desertification and livestock waste located in pastures along croplands. Water isotopes reflected evaporation in middle reaches and the effect of the disruption of natural events due to the dam construction.