Analysis of the Precipitation Pattern under Changing Climate in the Lower Kabul River Basin Nangrahar, Afghanistan

Precipitation and temperature are two factors utilized to assess the climate conditions in the area. The moderation and variability of the climate, particularly the annual discussion of temperature and precipitation, have garnered significant attention globally. In this regard, the current study investigates the changes in temperature and monsoonal rainfall over the long and short terms in the Lower Kabul Basin, Nangrahar province. Rainfall data from 1981 to 2021 were examined in this research. Statistical trend analysis methods, including Excel with various formulas, the Mann-Kendall test, and Sen's slope estimator, were employed to scrutinize and interpret the data. Nangrahar, characterized by its low-lying terrain and intersecting river systems, is part of the inactive delta of the large Hindu Kash Rivers and is situated in the lower Kabul basin. The study aimed to uncover the monthly trends and seasonal and annual variations in rainfall. The trend analysis revealed a negative trend line for December's monthly rainfall, while all other months exhibited a positive slope in the trend line. Analysis of historical precipitation data also indicated a clear regular variation, with dry months becoming drier and monsoon periods experiencing increased rainfall, making them more susceptible to floods. The annual mean rainfall highlighted that the Nangrahar region is one of the driest areas in the country.