Trends in extreme temperature and precipitation events over Zambia for the period 1981-2021.
Date
2025
Authors
Zulu, Memory
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Human activities such as burning fossil fuels, cutting down forests and livestock farming have caused an increase in the earth’s surface temperature by 1.0 °C since the preindustrial levels. Warmer temperatures over time are altering global weather patterns. These alterations have been resulting in
more frequent and intense extreme weather events that were previously unheard of in many regions, including Zambia. Extreme weather events such as hot spells, dry spells, flash floods, etc. pose many risks to water availability and food security. Agriculture in Zambia heavily relies on rainfall. The
shifting patterns of temperature and precipitation in Zambia have led to reduced crop yields, failed harvests, and challenges in animal farming. Consequently, food security is now at risk. The frequent occurrences of extremely hot days, floods, and droughts have severe implications on the livelihoods of many individuals and pose serious harm to the infrastructure such as roads, dams, and schools in the country. The districts are affected differently by the extreme weather events. Therefore, it is crucial to understand the annual trends in extreme temperature and precipitation events based on daily historical and current meteorological observations at a finer resolution for assessing climate change vulnerability at the local (district) scale and consequently designing local adaptation strategies. This study conducted a comprehensive evaluation of annual/seasonal trends in some selected extreme weather events by utilizing the ERA5 data set of resolution 0.5 x 0.5 degrees for the period 1981-2021. The research investigated the annual trend in the frequency of days with maximum temperature exceeding 35°C ( very hot day) as well as the maximum daily temperature across regions in Zambia. The study partitioned the regional domain of Zambia into three climate zones based on mean total seasonal rainfall. Findings reveal significant increases in both the frequency of days with maximum temperature exceeding 35°C and annual maximum daily temperature most especially in climatic zone 1 indicating urgent implications for agriculture and ecosystems. In terms of precipitation, the study examined seasonal total rainfall and the seasonal frequency of days when daily rainfall exceeds 20mm and 30mm thresholds. Results indicated a general decrease in seasonal total rainfall during the October, November and December (OND) season, and increasing trends regardless of some fluctuating patterns observed in the January, February and March (JFM) season. The analysis identified districts that are hotspots of the considered extreme weather events emphasizing the need for region-specific adaption strategies to address the negative impacts of weather events. These findings contribute to a broader understanding of Zambia’s climate dynamics and underscore the necessity for informed decision-making to enhance resilience against changing climatic conditions.
Keywords: Trends, Temperature, Precipitation, Extreme Events, ETCCDI Climate Indices.
Description
Thesis of Master of Science in Statistics.