Potential risks of landslides in the context of increasing extreme rainfall events in mountainous regions of Nghe An province

This study investigates the potential risks of landslides in mountainous regions of Nghe An province, Vietnam under the impacts of increasing extreme rainfall events. Using nonparametric statistical methods including Mann-Kendall test and Sen's slope estimator, the study analyzed rainfall trends from 1998-2020 across four observation stations. The analysis focused on rainfall in September, October and maximum rainfall intensity, which historically correlate with landslide occurrences in the region. Results reveal statistically significant upward trends in rainfall intensity across all stations, with particularly strong signals in September (Zs=6.50, p=0.05) and October (Zs=5.42, p=0.09) at Dua station. The Sen's slope estimates indicate substantial increasing trends, ranging from 4.90 to 6.48 for September and 4.00 to 8.60 for October. The significant upward trends in extreme rainfall events (β=5.96-9.90) further amplify these risks. This research underscores the urgent need for enhanced landslide risk management strategies in Nghe An's mountainous regions, particularly during the typhoon season when rainfall intensities are projected to continue increasing.