Document Type : Research Paper
Authors
1 Ph.D. student of climatology, Department of Physical Geography, Faculty of Social Sciences, University of Mohaghegh Ardabili, Ardabil, Iran
2 Professor of climatology, Department of Physical Geography, Faculty of Social Sciences, University of Mohaghegh Ardabili, Ardabil, Iran
Abstract
The severity and frequency of droughts become more complicated with the occurrence of climate change and is an important issue in the agriculture and water resources sector. The current research was conducted to predict drought in Ardabil, Ahar, Parsabad, Jolfa, Khoi, and Mako stations located in the Aras basin. For this purpose, the output of the CMIP6 general circulation model was predicted under the scenarios (SSP1-2.6), (SSP2-4.5), and (SSP5-8.5) for the precipitation data of 2024-2043. Then, using the Standardized Precipitation Index (SPI), drought characteristics on an annual scale during the base period (1985-2014) were measured with the future period. Validation of the model was done using R2, RMSE, MAE, MSE, and NSE indices. The results of the analysis of statistical indicators showed that the CanESM5 model has an acceptable ability to simulate precipitation. The forecasting results based on the CanESM5 model for the coming years showed that the severity of drought under all three scenarios will increase compared to the base period, which is caused by the consequences of climate change in the studied area. Also, the output of drought monitoring based on the SPI index showed that in the pessimistic scenario of SSP5-8.5, the number and intensity of droughts are more than the average and optimistic scenarios. The values of the SPI index for 2000-2020 in terms of drought-free areas obtained from TCI and VCI indices extracted from satellite images in the Google Earth Engine system showed that in all stations there is the highest correlation coefficient between the SPI and VCI index, which indicates the ability of the index VCI is to show the drought situation in Aras watershed.
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