ANÁLISE ESPAÇO-TEMPORAL DO ESPELHO D’ÁGUA DO AÇUDE TRUSSU ATRAVÉS DE SENSORIAMENTO REMOTO

Abstract

The storage and distribution of water for consumption and irrigation is of paramount importance in semi-arid regions due to the irregularity of rainfall. The water mirror can be described as the continuous surface exposed to the atmosphere of water bodies. The aim was therefore to analyse the spatialization of the water mirror of the Trussu Dam, located in Ceará, using images from the Landsat 7 and 8 satellites, during the dry season and to prove a statistical correlation between the volume of the reservoir and rainfall indices for the period 2011 to 2022. The Normalized Difference Water Index (NDWI) was used in the images to highlight the water bodies. Spearman's method was used for statistical correlation. For correlations involving rainfall indices, the variation in stored volume and water mirror in relation to the previous year was considered. The results show that between 2011 and 2019 the reservoir had a variation of -1,749.99 hectares of water mirror. The water mirror is positively correlated with the stored volume (0.993), and both were correlated with the rainfall indices, 0.818 and 0.627 respectively.