“…A limited knowledge of the unknown parameters requires a considerable amount of work to obtain optimal parameters and might induce the problem of convergence to the local optimum instead of the global optimum (Wang and Luus, 1980). In this study, each unknown parameter has its minimum and maximum bounds obtained by field observation, laboratory experimentation, and previous modeling studies (Bowie et al, 1985;HydroQual, 1987;Ambrose et al, 1994;Cerco and Cole, 1995;Park et al, 1995;Chapra, 1997;DiToro, 2001;Jorgensen, 2001b;Phlips et al, 2004).…”