Comparação entre dados observados CHIRPS e simulações do modelo WRF para eventos de precipitação intensa na Bacia do Rio Umbeluzi (2016-2023)

Abstract

This study aims to compare precipitation data observed by CHIRPS with simulations from the WRF model, focusing on intense precipitation events in the Umbeluzi River basin during the period from 2016 to 2023, in order to understand their relationship with flooding occurrences in the basin. The methodology was based on simulating precipitation episodes using the WRF model with configurations appropriate for the study region, followed by comparison with observational data from CHIRPS. The results highlight differences between the average precipitation values obtained from the two datasets. In general, CHIRPS showed higher average values compared to WRF for most of the events considered. For example, during the event on January 29, 2017, WRF recorded 0.21 mm, while CHIRPS reported 10.82 mm, and on January 31, 2021, the values were 0.06 mm for WRF and 21.03 mm for CHIRPS. Conversely, in certain events, such as February 16, 2017, the model presented higher average values than those observed (29.37 mm in WRF and 17.56 mm in CHIRPS). The comparison of average values reveals a tendency of the WRF model to underestimate intense precipitation, although it is able to represent the occurrence of events and the spatial distribution of precipitation within the basin. These results allow for the association of intense precipitation episodes with the occurrence of floods in the Umbeluzi River basin