Long Term Trend Analysis of Precipitation and Temperature in Southeastern States of Mauritania

This paper examines long-term trend analysis of precipitation and temperature in three southeastern states of Mauritania, namely, Aioun, Néma, and Kiffa. Mann–Kendall test and Sen’s slope estimator method have been applied to determine if there was an increasing or decreasing trend in climate data, with their statistical significance for the period of 1967-2024 for precipitation and the period of 1967 - 2023 for min/max temperature. The study area is under a unimodal rainfall regime where it receives the main rainfall during summer season, accounting for 85% of the total rainfall. The results of the study showed a significant increase in precipitation over time for Aioun station at the rate of 20 mm per decade at 1% significance level. while there is non-significant increasing trend at other stations. In terms of seasonal precipitation, Aioun station showed a significant trend in winter, spring and summer seasons with a negative trend for winter and spring while summer showed a positive trend at rate of 15 mm per decade. By contrast, there is no trend at Néma station at a 5% significance level, similarly for kiffa station even while winter precipitation decreased over time. However, annual minimum temperature had statistically significant (P>0.01) increasing trend at Aioun and kiffa stations at the rate of 0.4 and 0.3°C per decade, respectively. On the other hand, annual maximum temperature showed a statistically significant increasing trend at Aioun and Néma stations at the rate of 0.3 and 0.2°C per decade, respectively. Overall min temperature increased more rapid than max temperature in the study area.