Estimation of the weighted scores
The objective of this research is to map flood hazard zones in
Najran city. The decision factors to relate attributes to
suitability concerning a particular goal are the factors controlling
flood hazard in the study area. The primary decision factors
are considered in this study as listed in section 3 (see
Fig. 5). Once the decision factors are identified and selected,
sub-factors are identified to better describe these criteria. For
example, the surface slope is sub-divided into 7 sub-factors
(Eimers et al., 2000) (Pramojanee et al., 2001) and (Yalcin
and Akyurek, 2004). We used AHP, which is a multi-criteria
decision-making approach introduced by Saaty (1977) and
Saaty (1994). The AHP is a decision support tool, which is
used to solve complex decision problems. It uses a multilevel
hierarchical structure of objectives, criteria, sub criteria,
and alternatives. Three levels are used in our problem: goal,
factors criteria and spatial attributes. Each land use has a different
surface roughness value. These values (ranged from 0.03
to 0.1) were specified for different land use (see Table 6).