Temporal and Spatial Variation of Precipitation Indices at Dapoli Tahsil in Coastal Maharashtra

The objective of this research work is to study the temporal variations of precipitation indices (total precipitation, intensity, frequency, duration of wet and dry spells), that may be affected by climate change at three rain-gauge stations in Dapoli taluka during period of analysis (52 years for Harnai (1957 to 2008), 42 year for Dapoli (1972–2013) and 34 years for Wakawali (1980 to 2013). The study indicated that the annual total precipitation at three locations did not show a significant trend. However, the monthly changes in precipitation were significant at these locations. The annual precipitation along longitude i.e. from sea shore to Sahyadri hills is observed to be more significant as compared to that along the latitude. The first half time series (1972 to 1992) and second half time series (1993 to 2013) showed most significant increase in daily maximum and maximum consecutive 5-day precipitation at Dapoli during September indicating 61% increase in maximum consecutive 5-day precipitation. Simple intensity index did not show a significant trend during the period under analysis at all locations at 95% significance level, although a difference was observed between first and second halves of the series at Wakawali and at Dapoli during September, representing 18% and 24% increase in the intensity of precipitation, respectively. The difference between first and second halves was observed to be the highest at Harnai in October representing 54% increase in the intensity of precipitation.