Simulation of Stream Flow Hydrographs Using Flexible Distributed Hydrological Modelling (WetSpa-Python)

Hydrological simulation models are valuable tools for examining challenging issues related to watershed management such as the impact of climate change on water resources, the impact of urban planning on floods and droughts. In this study, WetSpa-Python model was developed to simulate daily flow hydrographs at the Arazkouse basin. This is an object-oriented, process-based modular model which has been developed based on the principles of flexible modeling in python. Data inputs included DEM, soil type, land-use, precipitation time series, temperature, and evapotration, which were acquired from nine meteorological stations for a ten-year period (from 2006-07 to 2015-16). Model calibration was performed in a limited manner by assigning rational values to 8 global parameters based on the best fit between the simulated and observed hydrographs. Model performance was tested via the Kling-Gupta index, and obtained 0.6 and 0.52 for the calibration and validation periods, respectively. The results of the water-balance analysis with the model indicated that the outflow of the basin constitutes 13.2 and 18.1% of total precipitation in the calibration and validation periods.