Aplicabilidade de modelos matemáticos na análise de processos de outorga: o caso da bacia do ribeirão Taquaruçu

Abstract

For a water rights permits is issued, it is necessary that the technicians of the managing body of water resources assess whether the water body has the capacity to meet the demand required for the uptake of water or wastewater discharge, considering other uses existing and local hydrology. Thus, the use of mathematical models to evaluate these criteria makes more efficient analysis, which allows the simulation of different intervention scenarios in a given basin. In this context, this study aimed to evaluate the applicability of mathematical models coupled to a GIS tool to estimate water availability and water balance between supply and demand of water basin of river Taquaruçu Grande, responsible for supplying 70% the urban population of Palmas - TO for different demand scenarios and discharge of effluents. For this, we used the hydrological model MGB-IPH to estimate water availability, which generated satisfactory results for the basin small territory, representing consistently seasonality of flow of the basin. These flow data were later used in the Decision Support System - SAD-IPH where simulations were performed on the quantitative and qualitative modules, involving three different scenarios of water demand and wastewater discharge. These simulations showed that the basin Taquaruçu stream already has stretches of river network in a critical situation regarding the availability, which is aggravated during the dry season and over the years. The basin has physical conditions that favor the maintenance of the quality of its waters. However, over the next 20 years, the water quality will degrade as the discharge of effluents is intensified. The results obtained in the three scenarios indicate that more efficient technologies should be adopted to reduce the input of pollutants to the basin and thus maintain the quality of water to meet the demand of existing uses. It follows therefore that the tools used are important to support the managing body of water and the basin committee in making decisions regarding the analysis and issuing water rights permits abstraction and discharge of effluents.