Towards a smart decisión-making for the sustainable management of environmental waters

DOLORES GUTIÉRREZ CACCIABUE; MACARENA ABDENUR ARAOS; RAJAL, VERONICA BEATRIZ

Chapel Hill

Simposio; 19th International Symposium on Health-Related Water Microbiology; 2017

Systematic monitoring of aquatic environments is carried out worldwide to assess their quality. This involves the measurement of different variables, which are indicative of water pollution. The presence of microorganisms mainly pathogens is of great concern because they are responsible for the 80% of the waterborne diseases. Due to the inability of measuring each of the pathogens present, the use of bacterial indicators has been established by legislation. Some guidelines also include physicochemical variables. Despite the importance of monitoring, data obtained are valuable for experts in the field, but lacks of importance for the population that uses water bodies, becoming a potential risk. For a global consciousness, it would be convenient to use tools that help understanding the current situation in a clearer and easily way. Multicriteria Decision Analysis (MCDA) are methodologies that allow making decisions taking into account both scientific discoveries and stakeholders priorities. Their purpose is to choose between different alternatives based on multiple criteria and know which one is the best. The aim of this work was to apply two MCDA methodologies in order to assess the impact caused by qualitative and quantitative variables on the quality of aquatic environments (AEs) in Salta, Argentina. The MCDAs methodologies chosen were: Analytical Hierarchical Process (AHP) and Multi-Attribute Utility Theory (MAUT). The alternatives analyzed were AEs previously monitored: Arenales River divided in two AEs: upstream and downstream due to their differences in quality; La Caldera and Vaqueros Rivers and Campo Alegre Reservoir. Also, each AE was divided in wet and dry season. Therefore, ten alternatives were considered. Then, criteria (or attributes for MAUT) and sub-criteria (showed in parenthesis) were selected: Qualitative: effluent receptor (industrial and domestic), recreational uses (primary and secondary contact), resource acceptability, general impacts (presence of trash, washing clothes and cars, wildlife impact); Quantitative: a Water Quality Index (WQI), calculated with nine variables: four physicochemical (Temperature, dissolved oxygen, turbidity, pH) and five microbiological (total and fecal coliforms, Escherichia coli, enteroccocci, Pseudomonas aeruginosa). AHP was solved using Expert Choice 11 Inc. and MAUT through the Generic Multi-Attribute Analysis.Besides some differences that these MCDAs have in terms of calculation of global utilities or objectives functions and sensitivity analysis, both of them showed similar results. The AE that suffered the greater decrease on its quality was the Arenales River downstream during wet season and the criteria which influenced the most was the effluent receptor. However, depending on the activities developed on each AE and the season studied, the impact of each criterion differ between them. These results will be useful on decision-making to reach an integrated management of water resources.