انجمن هیدرولیک ایران نشریه علمی هیدرولیک 2345-4237 5 2 2011 01 21 Flood Propagation Forecasting Based on Non-linear Diffusive Wave Equation پیش بینی نحوه انتشار سیلاب با استفاده از موج پخشیدگی غیرخطی 31 47 85454 10.30482/jhyd.2011.85454 FA محمد دانیالی احمدرضا غواصیه دانشکده صنعت آب و برق عباسپور جلال عطاری Journal Article 2010 03 22 Existence of a quick and accurate flood routing model is of great importance for river training as well<br />as flood forecasting and warning systems in order to prevent or mitigate flood casualties and damages.<br />Diffusive wave is one of the channel routing methods in which acceleration terms have been neglected<br />in momentum equation. Among different types of diffusive wave models, Cappelaere equation,<br />considering its unique features, was applied in present research. This model is an advection-diffusion<br />equation, including non-linear parameters, with main advantage of no need for topographic and<br />hydraulic characteristics of the river. In this paper, Leapfrog-Dufort Frankel finite difference<br />numerical scheme was used for discretization and numerical solution of the Cappelaere equation<br />which increases computational speed of flood routing. Furthermore, a novel method of estimating<br />celerity(C) and diffusivity (D) parameters was proposed which is superior to previous methods. In this<br />method, C and D parameters can be calibrated just by observed hydrographs in a reach and are<br />applicable for future flood forecasting in the same reach. By this method, absolute independency of<br />parameter estimation in diffusive wave routing method from river geometry, manning roughness and<br />bed slope is obtained. To validate the model and the proposed method of parameter estimation, the<br />routed hydrographs were compared with the dynamic Saint-Venant equations in a synthetic prismatic<br />channel. Furthermore, the model was calibrated in a 80 km reach, Yasavol-Gharegooni, of Ghezel-<br />Ozan river and results were tested against the observed hydrographs. Using the model, duration of<br />routing in the channel and river were found to be 15.7 and 59 seconds respectively. Maximum error in<br />peak discharge in the channel and river does not exceed 0.04% and 0.24% respectively. Concerning<br />time to peak, the maximum error in the channel and river were 0.87% and 1.57% respectively. Results<br />in the channel and the river showed that the proposed model is not only accurate in predicting peak<br />discharge and time of peak, but also is successful in Conserving mass of flood. https://jhyd.iha.ir/article_85454_02250cef0fdfeac7a9370f5922cb82f2.pdf