The impacts of climate change based on regional and global climate models (RCMs and GCMs) projections (case study: Ilam province)

Abstract

The climate change is one of the most important challenges facing the environment. In this study, climate change by air temperature and precipitation parameters is evaluated and compared for observational and future data. For the baseline period (1981–2016) and for future (2020–2080) detemined. To estimate future data, utilized the CNRM-CM5 and HadGEM2-ES models output the global climate models (GCMs) from the MarksimGCM database and the CNRM-CERFACS and MIROC-ESM models as regional climate models (RCMs) from the CORDEX project for the domain of south Asia is based on the representation concentration pathway RCP8.5 and RCP4.5 scenarios were considered. The results showed that is an increasing and decreasing trend for air temperature and precipitation in the baseline period, respectively. The validation of the models showed that the CNRM-CM5 model as a GCM model and the CNRM-CERFACS model as an RCM model have a higher performance in simulating climate change for study area. In fact, output of these models have close relation to the observed data. Evaluation of the temperature components (minimum and maximum temperatures) showed these components had an increasing trend in the baseline period and would have an upward deviation in the future. With respect to the changes in air temperature, precipitation and reference evapotranspiration (Eto) for the future, the status of water resources in the study area will decline significantly. Therefore, the effects of climate change are significant for the study area, which need to consider adaptive strategies such as; optimal water management, cropping pattern and resource management.