Exploring Rainfall Patterns in Diverse Nepalese Regions and Implications: A spatial and Temporal Analysis

Abstract

This article explores rainfall patterns in diverse Nepalese regions and presents a comprehensive provincial analysis of the spatial and temporal distribution of monsoon rainfall in Nepal during 2021 to 2023. The variation in topography, distinct landscape, and climatic diversity of Nepal significantly influences monsoon rainfall and its rainfall patterns, which are shaped by the completely interactive nature of geographical and meteorological factors. Utilizing data from 47 rainfall stations this study aims to investigate provincial rainfall variability and intensities to assess disaster risks. Present work reflects the spatial distribution of rainfall by showing provincial disparities and we observed that central provinces such as Gandaki received the highest amount of rainfall i.e. near about 2000 mm in monsoon season and exceeding 3000 mm annually in 2021. Meanwhile, western provinces, such as Karnali, experience significantly records the lowest rainfall dropping below 1000 mm in 2023. Altogether the amount of rainfall recorded spatially is declining each year in every province. Similarly, this study highlights the recent temporal distribution of rainfall by comparing the total rainfall of the monsoon season during study period. The analysis reveals that July emerges as the peak month for rainfall in the years 2021, and 2023. However, August also contributes to some provinces. Though the total rainfall fluctuates seasonally, June also shows the highest rainfall in the year 2022 except in Lumbini and Sudurpashchim due to broader climatic variations. We have also analyzed rainfall intensity and found an increase in extreme rainfall events, especially in Gandaki and Bagmati provinces, which poses risks of flood and landslides. Additionally, the increasing number of light rainfall days suggest potential drought conditions in provinces like Karnali and Madhesh. Provincial rainfall analysis provides a crucial insight for disaster risk management, agricultural planning, and water resource management in current socio-economic scenario of Nepal.