Analysis of Climate Change Impacts on Rainfall Trends in the Orsang River Basin, India

In a country India, in the most of the regions, almost 80% of the annual precipitation is concentrated during monsoon months. As a result, the inflows in the river and inflows available for the water resources projects are also concentrated in the monsoon season (i.e. June to October). In view of the changing climate, analysis of changing rainfall pattern bears importance for the safe operation of the hydraulic structures and also, for water and food security. In this study, monthly time period of the monsoon season and annual rainfall trends have been studied to assess the impact of climate change in the region. The monthly rainfall data series from 1970 to 2016 (47 years) have been made available for the raingauge sites in the Unch watershed of Orsang River. The Orsang River is a tributary of the Narmada River in the Gujarat State of India. The monthly and annual rainfall data series trend analysis has been carried out for these raingauges installed in a Orsang River basin. Four raingauge stations namely, Kalarani, Sanjuli, Vora, and Dhandhoda are installed in the Unch watershed of the Orsang River basin. Sanjuli and Dhandhoda are located in the Chhota Udepur Tehsil of Vadodara District, while Kalarani and Vora are located in a Sankheda and Tilakwada Tehsil of the Vadodara District respectively. It is summarized that the climate change impacts on the small-regional scale study area confirms the increase in the annual rainfall magnitude, decreasing June month rainfall, increasing July month rainfall, decreasing in the August month rainfall magnitude, decreasing in the intense rainfall in the month of August, and shifting of the monsoon season to start and finish late.