A Utilização da Simulação Dinâmica como Ferramenta de Apoio à Gestão de Bacias Hidrográficas: O Caso do Arroio Dilúvio em Porto Alegre, RS

The use of hydrological models to understand the water cycle behavior in a river basin is a current practice in planning for the development of water resources. However, it has not always been easy to use these models in the decision- making process. This is mainly due to the fact that to use these models, the stakeholders must have specific knowledge of the parameters that were modeled. Besides, the amount of elements needed to describe hydrological behavior may make it difficult to understand the system as a whole. In order to overcome this difficulty, it is proposed to use dynamic simulation models based on the fundamentals of the field of study known as “systems dynamics”, whose purpose it is to study complex systems considering all their constituent elements simultaneously. These models are constructed to make it easier to evaluate a complex system by means of analysis of the influence of each element that is part of it over the others and over the whole. Considering the river basin as the system to be studied, a dynamic simulation model was created to support the decision-making process in a practical case , the Pro-Diluvio Program of the City Administration of Porto Alegre (RS), which aims at promoting actions that will lead to water quality improvement in the Arroio Diluvio River basin, through the joint efforts of several municipal agencies. Among the difficulties encountered are the identification of the priority areas to fight pollution generated by the discharge of domestic effluents and diffuse pollution from rainwater. Among other things, it was observed that the use of dynamic simulation models allows the stakeholders to obtain more information about the problem, and applying these models in groups may be quite useful to facilitate negotiating the alternative to be adopted, thus reaching a consensus solution. Despite these positive results, it was also found that the simplifications performed during the conception of these models may lea