Diagnóstico de outorgas e vazões na unidade hidrográfica do Alto Ivaí - Paraná

Abstract

Population and economic growth have sharply increased the use of water resources. The demand for consumer goods and services has led to an increase in water consumption in all sectors of society. Thus, the objective of this study was to carry out a diagnosis of permits and outflows based on the permits issued to the Alto Ivaí Hydrographic Unit (Unidade Hidrográfica do Alto Ivaí) in Paraná state. To this end, data from water resource usage permits from the state management agency were used, with the delimitation of the study area being carried out by means of geographic coordinates. After sectioning the hydrographic unit area, it was possible to identify the types of uses (consumptive and non-consumptive), multiple uses; permitted outflows, purposes, permit exemptions for negligible use, water source intakes, the evolution of the issue of permits, and renewal of expired authorizations. By creating thematic maps using ArcGIS software, it was possible to physiographically characterize Alto Ivaí Hydrographic Unit. As a result, greater water intakes were detected for the agriculture and cattle-raising sector, as well as the greater number of permits in effect. As for the purpose of usage, human supply has the largest share of water intake within the consumptive uses (35.56%). In general, surface water sources have the highest authorized outflows, demonstrating the water potential of the region. The sum of the outflows exempted for negligible use is greater than the outflows authorized for the public administration sector, indicating high volumes of intakes, especially for the use in agriculture and cattle-raising. The increase in the issuance of permits for the last 10 years was significant, from 72 in 2011 to 400 in 2019. In contrast, the renewal rate of permits was only 2%, which may suggest the occurrence of irregular intakes, since most of the expired permits were for human consumption and livestock water supply. The Diagnosis of Water Permits and Outflows (DWPO) has shown itself to be an important tool to assist in data survey on the water resource usage, enabling identification of the largest water consumers within an established geographical limit.