watershed
Mahnaz Saber; Bromand Salahi; Roghayeh Maleki Meresht
Abstract
The SWAT model was used in this research to simulate the hydrological conditions of the Aras River basin in the future period. The model was calibrated based on the data of 1987-2006 and its validation was done in 2007-2014 with the SUFI2 algorithm and the SWAT model was calibrated based on the monthly ...
Read More
The SWAT model was used in this research to simulate the hydrological conditions of the Aras River basin in the future period. The model was calibrated based on the data of 1987-2006 and its validation was done in 2007-2014 with the SUFI2 algorithm and the SWAT model was calibrated based on the monthly flow rate of the selected hydrometric station. After selecting the optimal parameters and running the simulation in 350 simulator rounds, the values of the evaluation criteria were obtained in the calibration period and in the validation phase. To evaluate the water balance changes of the basin under the conditions of climate change from the downscaled data of the CNRM-CM6 climate model in the historical period (1985-2014) and the future period (2025-2100) under the SSP5-8.5 scenario were used as input data to the SWAT model. The findings showed that evapotranspiration of the Aras basin has wasted a large share of the precipitation of 272mm in the historical period and 351 mm in the future period of the basin, and the amount of infiltration and lateral flow, which are necessary to feeding underground and surface resources, is very low. Also in terms of land use, the minimum ET of the basin was calculated in the use of good pastures. Also, the findings showed that although in the future period the annual rainfall will be 79 mm more than the historical period, but a major part of it will be spent on evapotranspiration in the months of May to July.
Bromand Salahi; Mahdi Foroutan
Abstract
Monitoring the changes and fluctuations of precipitation in geographical areas can give a better view of the behavior of this phenomenon in the coming years. The purpose of this research is to investigate the precipitation situation in Ardabil Plain (Ardabil, Bileh-Daragh, and Kolour stations) and forecast ...
Read More
Monitoring the changes and fluctuations of precipitation in geographical areas can give a better view of the behavior of this phenomenon in the coming years. The purpose of this research is to investigate the precipitation situation in Ardabil Plain (Ardabil, Bileh-Daragh, and Kolour stations) and forecast it in the coming years based on the output of CMIP6 models by the CMhyd downscaling model. Then, using R2, MAE, MSE, RMSE, and Taylor diagram, the observational data of the base period were compared with the historical data of 5 GCM models from CMIP6, and the best model was selected for each studied station. The output of the top models was corrected for skewness by linear scaling method and based on SSP126, SSP245, and SSP585 scenarios, the precipitation of 2050-2023 for each station, forecast, and its trend were drawn with the Mann-Kendall statistic. The results showed that in the eastern and western areas of Ardabil Plain (leading to the heights of Talesh and Sablan mountains), the rainfall changes were increasing (2.80 mm). In the Ardabil station, the MIROC6 model with a correlation coefficient of 0.94%, and in Bileh-Daragh and Kolour stations, the MPI-ESM1-2-HR model with a correlation coefficient of 0.88% and 0.92%, respectively, have the highest accuracy in simulating the precipitation. Also, the results of the scenarios showed that the precipitation changes in Ardabil station in the future period compared to the base period under the SSP126, SSP245, and SSP585 scenarios will be 0.24, -6.36, and -2%, respectively.