Dear Alban,

First of all, "geomorphology" is a very large meaning term which extends from a clay particle to more or less square kilometers of watershed area. Bed forms, meanders, bed slope, wetted area and perimeter, granulometry of sediments , etc., etc.,  which are object of geomorfology effect a river's hydrodynamic regime, as more as watershed area, watershed relief energy, and so on.

I think you will to be more precisely. 

Hydrodynamically, geomorphology possibly would control the direction and velocity of the flash floods, and the sediment transport component depending on the overburden and lithology..

Dear Alban, geomorphology may affect river´s hydrodynamic regime, not only during the flash floods, which are rapid responses to a high intensity rainstorm, but also after the flash flood, since there could happen several modifications in the landscape, due to a flash flood. These modifications may include bank erosion, river and flood plain siltation, etc. These geomorphological modifications may, in the long term cause influence in the river´s hydrodynamic regime.

Best wishes,

Maria do Carmo

Dear Alban, geomorphology may affect river´s hydrodynamic regime, not only during the flash floods, which are rapid responses to a high intensity rainstorm, but also after the flash flood, since there could happen several modifications in the landscape, due to a flash flood. These modifications may include bank erosion, river and flood plain siltation, etc. These geomorphological modifications may, in the long term cause influence in the river´s hydrodynamic regime.

Best wishes,

Maria do Carmo

Dear Alban, geomorphology may affect river´s hydrodynamic regime, not only during the flash floods, which are rapid responses to a high intensity rainstorm, but also after the flash flood, since there could happen several modifications in the landscape, due to a flash flood. These modifications may include bank erosion, river and flood plain siltation, etc. These geomorphological modifications may, in the long term cause influence in the river´s hydrodynamic regime.

Best wishes,

Maria do Carmo

Geomorphology studies landforms and their processes which the river system remains significant. In the river system, certain concepts have been used in geomorphology in explaining them e.g the concept of grade, base level ,  dynamic equilibrium etc these concepts explains certain river processes such as river erosion, siltation and flooding with respect to the Davisian thought.

Check my article in research gate on historical background to Geomorphology. It could give you an idea/ reference.

Thanks.

Charles Anukwonke

Dear  Alban,  I am agree with Maria do Carmo. 

geomorphology affect river´s hydrodynamic regime, not  limited to  flash floods..

one of the most important affects after flash floods are landslides that  dam river flow and  sometimes to form lakes. These geomorphological modifications may, change route  of  rivers.

Best wishes,

khoshraftar.Zanjan university

Pls. refer to standard text book knowledge on fluvial hydrodynamics - I  personnaly recommend in include those on periglacial environments showing the most active features in an unique combination. That might satisfy your information needs.

Dear Alban,

Most has been said by previous contributors. The geomorphology may affect the river´s hydrodynamic regime by many ways... however; the main effects include the river flow direction and speed. The geomorphology may act as a frictional force and as boundary conditions in the hydrodynamic equations.

Kind regards

A.M.Hoguane