Spatial–Temporal Characterization of Rainfall in Uttarakhand: Mann–Kendal Test and Graphical Innovative Trend Assessment

Rainfall plays a significant role in hydrological projects, food security, landslide mitigations etc. Hence, tracking their pattern over a regular period becomes vital. The present study investigated annual rainfall trends for different daily rainfall categories (light, moderate and heavy) at the district level for Uttarakhand from 1991 to 2022 using the non-parametric (MK test) and graphical (ITA) tests. The variation in rainfall was evaluated using the coefficient of variation and annual rainfall ratio. The rainfall deviation for recent decades (D1: 1993–2002, D2: 2003–2012 and D3: 2013–2022) has been calculated using DRP. The finding shows that the region in the lesser and higher Himalayas of Uttarakhand experienced the maximum average annual rainfall. In the recent decade D3, rainfall across a large part of Uttarakhand was above-normal compared to D1 and D2. With the exception of Bageshwar and Garhwal, the prevalence of a rising trend in heavy rainfall was noted over the entire Uttarakhand. Further, the findings of this study may aid in pre and post-disaster mitigation of floods, landslides, and other rainfall induced disasters.