Analysis of Temporal Rainfall Variation at Vasai Block, Palghar District during 1998-2023

Abstract: This study examines the patterns and trends of monthly, seasonal, and annual rainfall in the Vasai block of Palghar district over a 26-year period (1998–2023). To evaluate rainfall variability, statistical parameters such as the mean, standard deviation, coefficient of variation, skewness, and kurtosis were computed. The findings indicate that the annual mean rainfall in Vasai is 2809.6 mm, with a standard deviation of 618.6 mm. The coefficient of variation is 22%, while the skewness and kurtosis values are -0.1 and -0.4, respectively. On average, the region experiences 78 rainy days annually. Linear regression analysis was employed to detect long-term trends and assess the magnitude of changes over time. The results reveal an increasing trend in annual rainfall during the periods 1998–2007 and 2018–2023, with gains of 118.4 mm and 58.2 mm per year, respectively. In contrast, a decreasing trend was observed between 2008-2017, with an annual reduction of -96.27 mm per year. Seasonal analysis further highlights Pre-monsoon rainfall exhibited a slight increase of 5.02 mm per year during 2018-2023 whereas Monsoon season declined by -93.8 mm during 2008-2017 & increasing trend observed during 1998-2007 & 2018-2023 by 151.8 & 53.4 mm per year respectively. The results of this analysis offer valuable insights for understanding regional climatic shifts and can support policymakers in developing effective climate adaptation strategies and water resource management plans. These results may useful for farmers in designing better irrigation strategies, and climate resilience crop cultivation.