There are many factors that influence the formation and development of floods, such as rainfall, soil, slope, land cover, drainage, and density. Therefore, a quantitative assessment of their importance is necessary, especially in the determination of flood risk zones, using the Analytic Hierarchy Process algorithm and Geographic Information System. In comparison with other methodologies, an obvious advantage of Analytic Hierarchy Process is the ability to solve multi-variable qualitative and quantitative problems with precise and trustworthy results. This paper presents the application of the Analytic Hierarchy Process algorithm in analyzing and evaluating the level at which various criteria affect flood risk in the Lam River basin. Some of the flood-causative factors considered in this paper are annual rainfall, soil, slope, land cover, drainage density, and relative slope length. These factors were chosen based on the physical conditions of the study area. The research results are the weight of different criteria. The higher the weight, the higher the effect of that criterion on flood risk. The computed weights show that annual rainfall and slope are the factors that contribute the most to flooding, based on decision-makers’ judgement. The results of this article can be used to construct a flood risk zoning map and flood susceptibility map for flood warnings in the Lam River basin, using the Analytic Hierarchy Process method and Geographic Information System technology. New research shows that Analytic Hierarchy Process can be trustworthy when assessing the level of influence of the different factors on determining flood-prone areas in the Lam River basin, as well as other basins.
Development of Hydrological Information System in the Chao Phraya River Basin