Trend analysis of rainfall and temperature in Metuge district, northern Mozambique

Abstract

Climate change poses significant economic, social, political and environmental challenges, with impacts varying depending on the geographical location and adaptive capacity. This study addresses data gaps by analyzing long-term trends in rainfall and temperature in the Metuge district from 1989 to 2022. The Mann–Kendall trend test, a non-parametric method, was used to detect trends, while Sen’s slope estimator quantified the magnitude of these trends. The seasonal analysis differentiated trends between the rainy season (October to March) and the dry season (April to September). The Mann–Kendall test revealed a decrease in overall annual rainfall and dry season rainfall, with a decrease of approximately 34.59 mm and 10.57 mm per decade, respectively. A significant decrease in trend was observed in March and the rainy season rainfall, with a decline of 33.83 mm and 42.75 mm per decade. Annual mean and seasonal minimum temperatures showed a significant trend, especially during the rainy season, with an increase of 0.25 °C per decade. The dry season and mean annual minimum temperatures increased by 0.17 °C and 0.2 °C per decade. The maximum temperature also showed a clear increasing trend, particularly during the dry season. The steady increase in temperature and decrease in rainfall in March and the rainy season highlight the noticeable effects of climate change in the Metuge district. These changes will likely exacerbate agricultural, water resources and public health challenges.