Spatio-temporal characterization of precipitation in the Middle and Lower Paraguay Basin based on satellite products and weather station data

Abstract. This study presents a temporal analysis aimed at identifying climatic patterns that influence precipitation behavior in the Middle and Lower Paraguay Basin, part of the Paraná River Basin in Paraguayan territory. This research utilizes satellite-based geospatial technologies to analyze the spatial and temporal variability of precipitation in the region. Satellite precipitation images were used for the period 2001–2023, available on NASA's GIOVANNI platform. The results from the classical exploratory statistical analysis allowed for the identification of data distribution, spatial and temporal variability of precipitation in the basin, areas with the highest accumulations, and drought periods, as well as extreme events associated with the El Niño-Southern Oscillation (ENSO) phenomenon, which impacts southern tropical America, including Paraguay. Through the use of remote sensing data and geomatics techniques, this study supports the goals of GEM24, which focus on applying geospatial technologies to address environmental monitoring challenges. The average monthly precipitation series shows a steady trend, with a decrease in recent years. The lowest average was in August 2004 (5.6 mm), and the highest was in December 2015 (345.22 mm). December is the month with the highest average precipitation, while August records the lowest value. The validation between the precipitation data obtained from the Giovanni platform and conventional weather station data, through correlation and linear regression analysis, revealed a strong and statistically significant relationship, indicating that the satellite model is suitable for predicting precipitation, although not perfect. Additionally, the study of temporal anomalies identified prolonged drought periods (2001–2013 and 2020–2022), with intensification in 2020, and periods of intense rainfall (2014–2019), highlighting the 2015 floods. The spatial precipitation anomalies during El Niño (2015) and La Niña (2020), using IMERG and CHIRPS data, allowed for the identification of precipitation spatial patterns. The areas with the highest precipitation were concentrated in the east and south of the country, while drier areas, such as the Paraguayan Chaco in the basin (west), recorded lower precipitation. This study underscores the role of satellite data and geomatics in environmental monitoring, demonstrating how these technologies can enhance our understanding of climatic patterns and extreme weather events. The findings highlight the importance of geospatial data in global environmental change assessments and the monitoring of regional climatic variability, which are central to the objectives discussed in GEM24.