The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Unsteady gradually varied flow wave propagation in a circular pipe is simulated using the modified Explicit and Characteristics Methods. The Extended Transport block of SWMM version 4 was also modified to include the effect of variable roughness for circular pipes. The effect of variable pipe roughness on the routed hydrograph attenuation and lag time is investigated. Routing simulations using variable roughness resulted in hydrographs with signification peak flow attenuation and lag time. Computer models are developed to calculate unsteady gradually varied flow problems. FORTRAN 77 codes are used for the calculations. The results are plotted using Lotus 123R4W and Microcal Origin graphics capabilities.