Investigating the trend of future climate change under the Representative Concentration Pathway scenarios using non-parametric Man-Kendall test (Case study: South of Ahvaz)

This research was developed to assess future climatic changes in the south of Ahwaz using General Circulation Models (GCM) based on IPCC-AR5. Temperature and precipitation data were extracted from 6 models in AR5. Then, EC-EARTH and CESM1-CAM5 for temperature and EC-EARTH and BNU-ESM for precipitation were used in LARS WG for downscaling. The results showed the temperature increase of 0.5 to 4 °C in winter and spring and 2 to 3 °C in summer and autumn. Precipitation will decrease in all months in the period of 2016–2035. This case study predicted the reduction of precipitation in most of the months. Investigation of the number of rainy days showed that this parameter had increased in all patterns. The results of the Mann-Kendall test also revealed that the precipitation didn’t have statistically significant trend.. Only EC-EARTH2.6 had an increasing trend for summer. This increase was significant at the 90% confidence level. In the case of the temperature parameter, the EC-EARTH8.5 pattern was increased in spring and summer and it was statistically significant at the 95% level. This increase was significant at the 99% confidence level for the summer season. CESM-CAM5-2.6 had an increasing trend significant at the 95% confidence level in summer. CESM-CAM5-8.5 had an increasing trend significant at 95% confidence level in autumn and winter. In the annual scale, the temperature parameter had an increasing trend significant at the 90% confidence level. Key words: AR5, Man Kendall, Temperature, Precipitation