Water balance in Volta Redonda city - Rio de Janeiro state – Brazil

Abstract

Cities do not perform assertive water resources’ management, mainly due to lack of hydrological studies in the literature. Volta Redonda City fits this context, since it experiences several extreme rainfall events. The aims of the current study are to present estimates for evapotranspiration, water shortage and percolation, to address critical water-availability months and to feature the climate in the investigated region, based on the water balance method by Thornthwaite and Mather. Meteorological data recorded between 2001 and 2021, provided by the National Water and Basic Sanitation Agency and by the State Environmental Institute, were used to analyze water availability in the investigated city. Volta Redonda presented actual evapotranspiration equal to 90.6 mm month-1; water deficit equal to 13.0 mm month-1 and water surplus equal to 22.8 mm month-1. Climate in the region is humid; it presents small water shortage throughout the year and critical water availability from March to October. These months require greater attention in water management processes due to high deficit values recorded for water balance. Results in the current study are pioneering, since they present the analysis of meteorological data previously used for air quality control, only. Volta Redonda needs assertive water management, since it recorded higher water deficits than surpluses in 13 of the 20 analyzed years.