نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
In recent years, destructive droughts in the Khashaf roud basin have received increased attention due to their significant impacts. Therefore, assessing drought variations is critical to ensure water management, human health, agricultural activity, and social development. In this study, the Run Theory was used to investigate the drought characteristics in historical (1989–2014) and future (SSP126 and SSP585, 2026-2050) periods in this basin based on observations and model simulations from Coupled Model Inter-comparison Project Phase 6 (CMIP6). The variations and risk analysis of drought characteristics based on SPEI6 were assessed by copula-based methods. In this thesis, first, the monthly temperature and precipitation data of meteorological station of Mashhad located in the Kashfroud basin for the years 1989 to 2014 were obtained from IRIMO and the quality control and homogeneity test of these data were performed. Screening of the AOGCMs of IPCC Sixth Report (CMIP6) models led to the selection of the MRI-ESM2-0 model. Bias correction was also done using two methods. linear scaling (LS) and distribution mapping (DM) were performed by CMhyd model. Based on the statistical criteria used, the LS method for precipitation data and the DM method for temperature were more accurate. The projcetion of temperature and precipitation variables for this basin for the near future period showed that the minimum and maximum temperatures will increase compared to the base period during 2026-2050. The average annual changes of these two variables under the SSP126 scenario by DM method will be +1.4 and +1.8°C respectively and under the SSP585 scenario it will be +1.7 and +2°C. Results indicated that precipitation was projected to increase under SSP126 and SSP585 scenarios. The drought duration and severity are shown to decrease based on MRI model projections compared with historical periods. Drought return periods of two drought characteristics for each scenario were also assessed by using the copula-based joint distribution. Based on the joint analysis of duration and severity for SPEI, both the “or” and “and” return periods in the future indicated decrease risks. Under global warming, moderate to extreme drought events with short duration, low severity were shown to occur more frequently in the near future, especially under the SSP585 scenario. Considering the current critical situation of the Kashf Rood basin, the application of the results of such research will lead to the improvement of risk management and drought risk in the water and agriculture sectors, increasing the resilience of the Kashf Rood basin and improving future planning for the aforementioned sectors.
کلیدواژهها English
Zhang, H., Chapman, S., Trancoso, R., Toombs, N., & Syktus, J. (2024). Assessing the impact of bias correction approaches on climate extremes and the climate change signal. Meteorological Applications, 31(3), e2204.