Sensitivity Analysis of Runoff Model by SWAT : LAP Lambert Academic Publishing : 9786200549624 : 6200549621 : 28 Jan 2020 : Determination of river runoff is essential in design and construction of most hydraulic structures including dams. In rivers with no measurement stations, the hydraulic models can be used for data estimation. SWAT is one of the most widely- used numerical models. In this model, input influential meteorological data as precipitation, temperature, wind speed, solar radiation and relative humidity as well as watershed data including the curve number and roughness coefficient are required to calculate the watershed runoff. The lack of weather stations in some watersheds increase the risk that the registered data in a station do not represent the whole watershed. Consequently, runoff estimation error should be determined. This research evaluates the sensitivity of the river runoff estimation to variations of the meteorological parameters such as precipitation, solar ra