meysam jafary godeneh

In recent decades, the increase in temperature has caused widespread climate change all over the world, especially in arid and semi-arid regions of Iran and Yazd province. The purpose of this study is to project climate change in Yazd province using the CanESM2 model and new emission scenarios (RCP) during 2021-2050 (near future) and 2051-2080 (distant future) and to study the trend of changes in the baseline period using the Mann-Kendall test. The statistical indices of R2, RMSE, and NSE were used to evaluate the performance of the CanESM2 model. According to the results, the model had an appropriate performance for projecting precipitation and temperature in the future period and was classified into good and very good classes in terms of capability. Investigating the trend of the annual change of temperature and precipitation in the baseline period showed that the temperature had an increasing trend under most scenarios and stations, while the trend of the change of precipitation was no significant. The results of temperature changes in Yazd province indicated an increase of 2.2, 1.2, and 2.5 °C during 2021-2050 and 2.28, 3.19, and 4.77°C during 2051-2080 under RCP2, RCP4.5, and RCP8.5 scenarios, respectively. Changes in precipitation in Yazad province during the winter season showed a decrease in precipitation by 32, 26, and 34% during 2021-2050 and by 32, 32, and 5% during 2051-2080 under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively.

Use the output of atmospheric general circulation models to understand the weather conditions and to prevent the spread and consequences of climate change on groundwater resources in all ecosystems, especially in arid and semi-arid regions is necessary. The present study was conducted to investigate the impacts of climate change on groundwater level fluctuations in Kerman plain, Iran. In order to investigate the impact of climate change in future periods, the CanESM2 climate model and SDSM4.2 software were used under RCP2.6, RCP4.5 and RCP8.5 emission scenarios. Then, GMS10.0.5 was used for quantitative modeling of groundwater in Kerman plain. The mathematical model prepared for the steady state in 2002-2003 was calibrated over 2002-2012 in 120 steps for the unsteady state condition and the 2012-2015 period for the calibration. The results of climate scenarios in the upcoming period (2006-2030) showed that temperature will increase by 1.12, 1.23 and 1.37 degrees Celsius while rainfall will increase by 14.69, 19 and 26.29 percent in RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively. The results of climate scenarios showed that in spite of increased rainfall and the assumption of constant utilization of groundwater, the average groundwater level in RCP2.6, RCP4.5 and RCP8.5 scenarios in the upcoming period would be lower than the water level compared with the base year (2002-2003), by 7.19 and 7.26, and 7.33 meter in the whole region, respectively. It is recommended that measures to deal with global warming resulting from climate change and over-exploitation of groundwater resources by reforming cropping patterns, irrigation new methods.

Assessment of climate change in arid and semiarid areas where water crisis is taken it as a matter of special importance. Therefore, the purpose of this study was to investigate climate change forecasting in Kerman city using general atmospheric circulation models available in LARS-WG6 software (EC-EARTH, GFDL-CM, HadGEM2-ES, MIROC5 and MPI-ESM-MR) under scenarios RCP4.5 and RCP8.5 for the period (2020–2050) and estimate its maximum precipitation over the various return periods during the base period (1961–2010) and future (2020–2050) using the Gamble distribution. The results showed that all five models have the same response in increasing the minimum and maximum temperatures in the city so that the maximum increase in the minimum temperature in GFDL-CM, HadGEM2-ES, MIROC5 and MPI-ESM-MR models is the results were 3.56, 2.73, 2.33 and 2.30 degrees Celsius, respectively. Also the maximum temperature in the RCP4.5 scenario in May, September, May, September and July, respectively, in EC-EARTH, GFDL-CM, HadGEM2-ES, MIROC5 and MPI-ESM-MR models, respectively, increased by 2.20, 2.82, 2.46, 1.98 and 2.38 °C, respectively. Precipitation decreased by 19.05% and 4.62% in EC-EARTH and MIROC5 models, respectively. The results show that maximum precipitation will occur with higher rainfall in all models except MPI-ESM-MR. Finally, it can be concluded that with increasing return period, the maximum amount of probable precipitation increased under RCP4.5 and RCP8.5 scenarios and was more severe under RCP8.5 scenario.