Assessment of rainfall variability, trend and meteorological drought in North Interior Karnataka (NIK)

Abstract

This study investigates the rainfall patterns, trends, and drought characteristics of the North Interior Karnataka (NIK) India, over a 30-year period (1991–2020). The research uses historical daily rainfall data obtained from the Karnataka State Natural Disaster Monitoring Centre (KSNDMC) and applies statistical methods such as the Mann-Kendall (MK) test, Sen’s Slope Estimator, and Linear Regression Analysis to assess temporal rainfall variability and trends. The analysis reveals significant spatial variability in rainfall across different seasons, with the Southwest Monsoon contributing the most consistent rainfall. However, the study identifies concerning trends, including a decline in rainfall during the Northeast Monsoon and a general decrease in annual rainfall in some districts. Drought characterization based on rainfall departures further highlights the vulnerability of the region, with negative departures observed in several seasons. The findings emphasize the importance of understanding rainfall variability to enhance agricultural resilience and water resource management strategies in semi-arid regions. This study provides a comprehensive understanding of the region's climatic trends and lays the foundation for future research and policy development aimed at addressing the impacts of climate change in the North Interior Karnataka.