A long-term analysis of hydro-meteorological trends across the Omo Gibe River Basin

ABSTRACT Understanding the effects of climate change on rivers is essential for managing water resources. The study manipulates the timing of low-flow occurrences with precipitation and temperature to observe how the rivers respond to climate change. The Mann–Kendall was used to illustrate the patterns in temperature, precipitation, and water flow data throughout the research area using a variety of methods. The study revealed that March and April have the lowest flow and highest temperatures, whereas December and January have the lowest rainfall and temperature, respectively. Low temperatures and low rainfall are also associated with a non-perennial flow regime. Conversely, the least amount of rainfall and the highest temperatures were associated with the low flow in the perennial flow type. According to the modified Mann–Kendall and Sen's slope, this is based on hydrological modeling, streamflow increased by 36.6% and decreased by 63.4% across the research area between 1990 and 2022 as a result of rising maximum and minimum temperatures. The study's conclusions serve as a foundation for further investigations into Ethiopian river hydrology, which may aid in the management of water resources and offer a way for researchers to suggest ways to improve low-flow rates throughout the study area.