A Web-GIS for decision making to achieve water quality standards of water bodies through collaborative watershed modeling

ABSTRACT Ensuring compliance with the minimum Water Quality Standards stipulated by law demands the implementation of strategic measures within the watershed. Water pollution modeling serves as a tool to guide the formulations of effective pollution control strategies. However, the inherent complexity of calibration, spatial-temporal variability, and uncertainty, in addition to effective communication of technical information to decision makers, makes it challenging to prioritize actions, implement them, and allocate resources efficiently. This paper presents the implementation of a Web-GIS for decision making support which combines collaborative hydrological and hydrodynamic modeling results with an interactive visualization of the Paranapanema river basin in the South of Brazil. The Web-GIS aimed to overcome the difficulty of presenting scientific results to decision-makers, gathering and harmonizing diverse datasets. Combining information from the watershed, the pollutant loads estimations for three substances (phosphorus, nitrogen, and BOD), the resulting concentrations in rivers and reservoirs, as well as the results for different future scenarios into a unified platform. It is expected that decision-making regarding water bodies framework will be facilitated by identifying the primary sources and pathways of pollution, prioritizing basins with the highest load production, an determining realistic possibilities of load reduction through effective measures