Case study evaluation of geomorphologic rainfall ‐ runoff model, incorporating linear infiltration expression

This paper presents case study applications for the hydraulically‐based geomorphologic Instantaneous Unit Hydrograph (IUH), developed by Diaz‐Granados et al. (1986). This IUH was derived as a function of watershed geomorphology and stream response to lateral inflows. This response was determined by solving one‐dimensional linearized equations of motion including a simple infiltration expression approximated by an infiltration coefficient multiplied by the streamflow discharge. Three gauged watersheds in Saudi Arabia are selected as case studies. A procedure for estimating the stream response parameters (the flow depth, the flow velocity, and the infiltration coefficient) is provided. A comparison is made between the observed and computed hydrographs and an evaluation of the IUH results and limitations is provided.