“…This model is based on the cascade of the reservoirs and links rainfall to runoff (Anshuman et al, 2021;Zhang et al, 2021;Chiew et al, 2022). Scientifically, the model was improved by Perrin et al (2003) and applied by many scholars such as (Ruelland et al, 2010;Kunnath-Poovakka and Eldho, 2019;Zeng et al, 2019;Kodja et al, 2020;Zafari et al, 2022) in various climate regions. The GR4J is a global conceptual model for rainfall-runoff that needs 4 parameters: X 1 , the maximum volume of the production stock (mm); X 2 , the coefficient of groundwater exchange (mm); X 3 , the maximum volume of the routing store (mm); and X 4 , the time highest ordinate of hydrograph unit UH1 (day) (Figure 2).…”