Performance Evaluation of BNU-ESM and MIROC-ESM models in Global Warming with a view to Future Climatic Parameters and Droughts (Case study: Gorganrood Catchment, Golestan Province)

Subject Areas : CLIMATOLOGY

دنیائی Donyaii ¹ ( Water Resources Expert - Golestan Regional Water Company )

Received: 2022-03-01 Accepted : 2022-06-05 Published : 2022-06-21

Keywords: drought, SDSM, RCP scenarios, Change Factor,

Abstract :

In the present study, the effect of climate change on climatic parameters such as temperature, precipitation and future droughts in Gorganrood catchment were evaluated using the output of two general circulation models called MIROC-ESM ﻭ BNU-ESM under three scenarios (i.e.,  RCP 2.6, RCP4.5 ﻭ RCP8. 5) for the two periods as the near future (2025-2060) and the far future (2061-2095). The outputs of MIROC-ESM and BNU-ESM model were downscaled by SDSM model and Change Factor method, respectively. In order to evaluate the performance of the two methods, the statistical indices such as R, RMSE and NSE were applied. And to assess droughts, the standard precipitation index (SPI) was used annually during the baseline (1961-2020) as well as the future periods. The results showed that the SDSM model has a higher performance in predicting both temperature and precipitation parameters than the Change Factor method. The results of temperature and precipitation changes in both near and far future periods determined the effect of Global Warming on the future climate of Gorganrood catchment, so that the average annual temperature increases in all scenarios in both models, while reduction in the average annual rainfall. Moreover, according to the results of both MIROC-ESM ﻭ BNU-ESM models, the annual SPI values will decrease in both near and far future periods under all three scenarios compared to the baseline period while the increases in meteorological drought. The results of general circulation models showed that the MIROC-ESM model estimates the lowest amount of rainfall, the highest values of temperature and the highest number of years with severe drought compared to the BNU-ESM model.