The Use of Bias-Corrected CMIP5 GCM Data to Analyse Temperature Variation in Puthimari River Basin- A Transnational Sub- Basin between Bhutan and India

Using five different CMIP5 climate models under the scenarios of RCP4.5 and RCP8.5, we analysed maximum, minimum and mean temperature over Puthimari river basin, that covers parts of Bhutan and North-eastern region of India. Historical period from 1970-2005 and future three periods, 2025-49, 2050-74 and 2075-99 were considered to understand the effect of global warming in the basin. Monthly Maximum, minimum and mean temperature variations analysis showed increase in temperature from 1970 to 2099 for all the models under both the scenarios. The study indicates that the average maximum, minimum and mean temperature over the basin will rise by 1.13-2.49°C, 1.3-2.64°C and 1.21-2.6°C respectively from in 2075-99 compared to the historical period under RCP 4.5. Again, these temperatures will increase by 2.68-3.89°C, 2.85-4.74°C and 2.76-4.53°C under RCP8.5 towards the end of the century. The linear trend analysis of maximum, minimum and mean temperature indicates rising trends in future over the basin.