Investigating the Hydrological Drought Index Using the SWAT Model (Case Study: Qatur Chay Watershed)

Mohammad Hossein Zadeh, Mahsa; Rezaie, Hoseyn

doi:10.22034/ceej.2025.65202.2409

Investigating the Hydrological Drought Index Using the SWAT Model (Case Study: Qatur Chay Watershed)

Authors

¹ WaterEng. Agricultur Urmia University IRAn

² Urmia University

10.22034/ceej.2025.65202.2409

Abstract

Climate change and increased drought duration cause an increase in area of barren and a decrease in vegetation cover, thus increasing the probability of flood events human and financial losses. In the research, the drought index in the Qatur catchment and the determination of the length of the wet and drought were used from the SPI index. In the following, the flow behavior in the basin was used to analyze the hydrological phenomenon and the uncertainty of sensitive factors. Using the monthly runoff statistics of the basin(1990-2018) in the SWATCUP and the SUFI2 algorithm, the performance was evaluated by selecting70% of it for calibration and30% for validation. The values of the Nash-Sutcliffe coefficient in the calibration periods ranged from 0.8-0.52 and the validation ranged from 0.7-0.46 at the hydrometric stations, indicating the good efficiency of the SWAT model. The results of the SDI hydraulic drought index model were used to analyze the region. The results showed that in the upstream parts of the watersheds, the alignment of the SPI and SDI indices was observed at the Molhazan and MusaQoli stations, and in the other stations, there is no specific alignment between the indices, which is due to the lack of alignment related to surface water withdrawal along the route to the outlet point.Lack of data sufficient data to calculate the drought indices, the SWAT model can be used to simulate predictions and statistical gaps, and to evaluate the causes of land use changes, a comparison two indices can be used.

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