Applications of geomorphologic and kinematic wave models to wadis in Saudi Arabia

Abstract EN

The hydrologie records available in the Kingdom of Saudi Arabia are generally inadequate for detailed analysis of basin response to rainfall.

Therefore, traditional runoff estimates, based on the detailed analysis of the historical runoff and rainfall records do not seem to be promising.

Thus, an attractive alternative appears to be the development of runoff prediction models with dependence on the geomorphol- ogy of watersheds rather than rainfall runoff records.

In the study reported herein, four versions of the Géomorphologie Instantaneous Unit Hydrograph (GIUH) Model and a Kinematic Wave Model have been applied to three gauged watersheds in Saudi Arabia.

The simulations revealed that parameters such as peak discharge, time to peak, and the shape of the hydrograph were very sensitive to the streamflow velocity.

The Kinematic Wave Model DR3M applications showed that, for small watersheds like Midhnab, the kinematic wave celerity is the most representative streamflow velocity.

For larger watersheds, such as Wadi Khat and Jawf, however, the GIUH model applications show that the dynamic wave velocity is the most representative one.

A comparison between the model simulations and observed hydrographs showed that the simulations of the GIUH model based on the exponentially distributed streamflow travel