Area-volume model for Guarapiranga Reservoir using NDWI index

Abstract

Dams represent an important source of water for supply purposes of urban areas. The water volume variation stored in these reservoir can be estimated from empirical area-volume relationship, in which the area of the reservoir filled by water can be derived from remote sensing techniques, emphasizing those derived from the use of the Normalized Water Difference Index (NDWI) calculation. For the establishment of the area-volume model at the Guarapiranga Reservoir, one of the main sources of water supply in the Metropolitan Region of São Paulo, 21 images with the NDWI index were produced using Landsat-8 OLI satellite images between January 2015 and January 2020. The regression analysis of the area covered by water and the volume measured at the Guarapiranga Dam, allowed the development of an empirical area-volume model with R² of 0.79, demonstrating the feasibility of using this approach for realistic volume estimates. of stored water.