چكيده فارسي :
As the result of flooding, rivers shape, cross-sectional geometry, and hydrological built materials change from time to time. Therefore, in a realistic sediment routing and flooding design and prediction, it is necessary to incorporate effects of such engineering consequences on mechanics of flooding. In this study a number of variables were looked at, these are non-uniform built environmental factors including; flow components, vegetation covers, bed materials, sediments sizes gradation, grain sorting and armouring, on hydraulics of flow and sediment transport of natural rivers. A linear and non-linear, two phase flow and sediment coupled (LCM), (NCM) components were considered for design and prediction of hydraulics and hydrology routing of the catchments. The nonlinear two phase flow-sediment coupled models (NCMG), incorporated with bed materials sediment sorting and armouring algorithm worked well for flooding prediction and analysis of graded sediment materials. Hydraulics characteristics of natural rivers in draught catchments, Kajoo –Saravan rivers basin were selected as a case study and the resultsof application of developed models to flow and sediment variations were discussed.