Sampling Sites Selection Based on Watershed Drainage Sig Analysis to Assess ENVIRONMENTAL Impacts of Feedlots and Poultry Farms

OSER, FEDERICO; IRIGOIN, JULIETA; MURPHY, KEVIN; CELLONE, FRANCISCO ALDO; SALGADO COSTA, CAROLINA; NATALE, GUILLERMO; DEMICHELIS, SANDRA

Congreso; SETAC Latin America 14th Biennial Meeting; 2021

The development of conservation strategies requires information about the spectrum of environmental conditions adequately distributed over a region. This is possible only if data collection is carried out through representative and adequately designed sampling. This study is part of a research project that aims to study the quality of the environments where native anurans with their infectious organisms inhabit. The study area is within the El Pescado stream basin (Buenos Aires, Argentina), a protected area due to its ecological importance. However, in recent decades it has undergone changes in land use associated with urban growth, the development of intensive agricultural production and the installation of feedlots and poultry farms, which together alter the hydrogeochemical characteristics of the basin and therefore its environmental quality. In this work we present a hierarchical methodology for the selection of sampling sites for the analysis of water quality in the Cajaravilla stream, tributary of El Pescado stream, in relation to feedlots and poultry farms location using Geographic Information Systems. Based on digital elevation models of the area of interest, sub-basins, micro-basins, drainage systems and areas of waterlogging of El Pescado and Cajaravilla streams were delimited and modeled with the QGis Desktop 3.18.2 program using the GRASS r.watersheed and r.water.outlet pluggins. Contour lines at 2 and 5 m asl were extracted to establish the sites that constitute permanent wetlands. The analysis of the digital models obtained and the georeferencing of feedlots and poultry farms allowed selecting suitable sites for sample collection of surface water, and subsequent measuring of the concentration of nutrients and other possible contaminants such as pharmaceuticals and agrochemicals. These measurements will allow us to analyze the impacts of these establishments on the water quality of the Cajaravilla stream.