The research presented in this article formulates an efficient
methodology to accurately delineate the flood hazard areas
in Najran city, KSA. Flash flood is a natural hazard that poses
a risk to both populations and structures within the affected
areas. There are several factors that affect the amount of runoff
which help determine the intensity of flooding. Therefore,
physical characteristics such as impervious surfaces, the
hydraulic rating of soil, and flow accumulation of water were
combined with demographic characteristics to create a composite
flood hazard index