Climate change impact assessment on precipitation and temperature variations using emission scenarios (Case study: Kashmir climatic region)

Climate change affects extreme events such as floods and droughts. This research was conducted in the watershed of Kashmar City in Khorasan Razavi province and the output of general circulation models from the CMIP5 model series was used to check the performance and validity of these models in predicting the climatic parameters of precipitation, average temperature, maximum temperature, and minimum temperature during the period 1989-2005. The best model was selected using the evaluation indices of the determination coefficient, the root means squared error, the absolute mean error, the correlation coefficient, and the mean squared error. Finally, the BCSD method was employed to downscale the data for three time periods near future (2020-2038), middle future (2039-2069), and far future (2070-2100) under the IPSL-CM5A-MR model and future emission scenarios (RCP2.6, RCP4. 5, RCP6, RCP8.5). The Mann-Kendall statistic test was used in order to investigate the trend of changes in monthly, seasonal, and annual rainfall and temperature variables. The results of the model evaluation indices for four climate models indicated the highest performance of the IPSL-CM5A-MR model in simulating precipitation and temperature with a high correlation coefficient and relatively low error indices compared to other models. The results of the investigation of the rainfall trend showed that in the far future, the rainfall component will be completely decreasing and it will have the largest decrease under the RCP8.5 scenario with a value of -41.12 mm. The average temperature is also increasing in all months and the maximum increase in the average temperature in the far future under the RCP8.5 scenario is 7.58 °C. The amount of minimum temperature and maximum temperature increases in all months, and the maximum increase of minimum temperature in the far future interval under the RCP8.5 scenario is 8.35 °C. Furthermore, the maximum increase in the maximum temperature in the far future interval under the RCP8.5 scenario is 7.09 °C.