Interdisciplinary approach to the ecological status assessment of Rio Quequén Grande watershed in Argentina

The aim of the research is to recognize natural and anthropogenic spatial heterogeneity and to test methodologies for ecological status assessment of RQG watershed, integrating abiotic and biotic data together with all the available information. A dedicated Geographic Information System (GIS) is developed and an interdisciplinary approach is implemented. The watershed is characterized, using an integrated informative system of geological, geomorphological, sedimentological, hydrological, geochemical, land uses and biological information. Textural and geochemical river bed sediments data and water chemical parameters of the main tributaries and the main course were also monitored. Bankfull channel and caliche outcrops crossing the RQG channel were mapped and the fluvial cross sections were surveyed. The hydrological and hydraulic analyses have been carried out. All the data and analysis results are recorded in the dedicated GIS. As a preliminary approach, a biological monitoring campaign was defined and samples of principal nutrients analyses were collected. General habitat quality was also evaluated and benthic algal communities, aquatic and riparian vegetation were sampled. The results indicate that the monitored rivers have an insufficient water quality possibly related to the diffused pollution due to intensive agricultural activities. Even if the bio-monitoring activities need to be continued, and the number of monitoring sites need to be increased, the preliminary obtained results by the monitoring campaign and the modelling, integrating with the GIS, are giving encouraging response.