Investigationofdifferent time scales rainfall-runoff modeling and calibration using HMSSMA

Performance of hydrological models are used in a variety of issues of real time flood forecasting to design water structures and policies to prevent from the effects of extreme hydrological events (floods and droughts), they depend on how they are calibrated. In these models, the values of some parameters can be estimated with observation and direct measure. But some others are not directly observable and their estimation is done by indirect techniques of model fitting in historical data. Purpose of this study is Investigating and calibration hydrological parameters of Soil Moisture Accounting model (HMS SMA) for estimating runoff in the time scale monthly. Results confirmed the ability to HMS SMA Model in predicting discharge and simulate process rainfall-runoff on a monthly time scale.