Local and regional spatio-temporal characterization of rainfall and temperature across agro-ecological zones and seasons in the lake Hayk and Ardibo catchment, Ethiopia

Abstract

Understanding local and regional climate trends is essential for effective planning and resource management in the context of climate change. This study evaluates and characterizes the spatio-temporal variability and trends of rainfall and temperature across agro-ecological zones (AEZs) and seasons in the Lake Ardibo and Hayk catchment from 1960 to 2021. We analyzed data from 36 stations across eight AEZs to assess climate conditions at local and regional level. Using the MM-Kendall test through R packages using high-resolution WorldClim, we focused on trend, coefficients of variation (CV), and standardized rainfall anomaly (SRA) for each station and AEZ. The results reveal significant differences in climate elements, highlighting unique patterns among AEZs and stations. Rainfall demonstrates an increasing trend in both annual and during FMAM and JJAS seasons, with rates ranging from 0.15 mm/year to 1.72 mm/year. In contrast, ONDJ season exhibits a declining trend at a rate of -0.08 mm/year. Temperature analysis shows that the mean annual maximum temperature (Tmax) ranges from 19.11 °C to 31.30 °C, while the mean annual minimum temperature (Tmin) ranges from 6.82 °C to 15.37 °C. Both Tmax and Tmin are increasing across AEZs, accompanied by significant seasonal and annual variability. These climatic changes have led to shifting boundaries of AEZs, which may impact agricultural productivity, water resource availability, and ecosystem sustainability. This research underscores the importance of integrating remote sensing and GIS approaches with high-resolution WorldClim data to examine climate dynamics in medium-sized catchments. It enhances our understanding of Ethiopian climate dynamics and provides valuable information for environmental management, policy-making, and climate change adaptation planning.