Analyzing Temperature, Precipitation, and River Discharge Trends in Afghanistan’s Main River Basins Using Innovative Trend Analysis, Mann–Kendall, and Sen’s Slope Methods

Abstract

Afghanistan, a nation already challenged by geopolitical and environmental pressure, faces severe climate change impacts, evident through rising temperatures, decreasing precipitation, and reduced river discharge. These changes profoundly affect the country’s water resources, agriculture, ecosystems, and well-being. This study analyzes trends in mean annual temperature, precipitation, and river discharge across all five of Afghanistan’s river basins from 1980 to 2022, utilizing an innovative trend analysis (ITA), the Mann–Kendall (MK) test, and Sen’s slope (SS) estimator. Climate data were derived from the CRU TS.v4 and TerraClimate gridded datasets, while river discharge data were obtained from GloFAS-ERA5 datasets. The results reveal significant climate shifts, including a notable 1.5 °C rise in mean annual temperature, significantly higher than the global average of 1.3 °C, a 1.2 mm decrease in mean annual precipitation, and a −128 m3/s reduction in river discharge across all basins since 1980. Climate change impacts were particularly severe in the western part of the country. These findings underscore the strain on Afghanistan’s vulnerable water resources, with critical implications for agriculture and water management, highlighting the urgent need for adaptive strategies to mitigate climate-induced risks.