Impact of Climate Change on Rainfall Trends, Variability and Dry Spells Pattern in Central Maharashtra Region

Abstract

The entire study area falls in the rain shadow zone; thus, the region witnesses recurrent rainfall scarcity conditions. Therefore, the rainfall data for 47 years (1975 to 2021) was processed to study the statistical characteristics and trends of weekly, monthly, and annual rainfall using the Mann-Kendall test. The magnitude of the trend was determined using Sen's slope estimation method. The mean annual rainfall of the Central Maharashtra Region was 593 mm. June, July, August, September, and October receive an average rainfall of 113.5 mm, 86.7 mm, 94 mm, 157 mm, and 76 mm, respectively. The mean onset date of the effective monsoon lies between 1st June and 12th July in the study area. Hence, this period should be considered for sowing selected Kharif crops. Using the Mann-Kendall test (M-K), trends in annual rainfall show an increase. Using the Mann-Kendall test (M-K), trends in weekly rainfall show an increase for the 36th SWM and a decrease for the 39th SWM. Analysis of heavy rainfall events (>50 mm) demonstrates a rising frequency, particularly in recent years, indicating a shift toward high-intensity, short-duration rainfall. Intra-seasonal dry spells and drought analysis reveal that moderate and severe droughts occur in 21% and 6% of years, respectively, highlighting the region’s vulnerability to rainfall variability. The coexistence of droughts and extreme rainfall events underscores the growing climate risk, emphasizing the need for adaptive water management, soil and water conservation, and climate-resilient agricultural practices. These findings provide critical insights for planning sustainable agriculture and mitigating the impacts of erratic monsoon rainfall in semi-arid regions.