Análise do comportamento espaço-temporal da precipitação com base em estimativa de satélites: um estudo no Rio Grande do Sul

Abstract

The management of water resources constitutes an essential pillar for socioeconomic development and for maintaining environmental sustainability, especially in territories marked by high climatic variability, such as Rio Grande do Sul. However, conventional precipitation monitoring methods, based on terrestrial rain gauge networks, have limitations regarding spatial coverage and measurement continuity, which compromises the detailed understanding of rainfall patterns and the capacity to respond to extreme events. In this scenario, remote sensing stands out as a technological alternative with great potential. Therefore, this study aimed to analyze the spatiotemporal behavior of precipitation in the state, based on the GPM/IMERG product (1999–2024), analyzing annual totals, annual maximum intensities, and the coefficient of variation, in addition to detecting trends using the Mann-Kendall test. The methodology involved downloading, preprocessing, and analyzing historical series of precipitation estimates, applying spatial statistics and geoprocessing techniques to assess rainfall variability and delineate areas of higher rainfall concentration. The results indicated that the GPM/IMERG estimates show good coherence with regional rainfall patterns, identifying a decreasing precipitation gradient from north to south. The use of the product proved efficient for identifying seasonal trends and improving the diagnosis of extreme events, also revealing a significant reduction in the maximum hourly intensity and an increase in daily variability over the historical series.