Floods are considered to be one of the most costly natural hazards in the Lam river basin causing infrastructure damages as well as devastating the affected area and relatively high death toll. So prevention is necessary for shielding lives and properties. The flood management on the Lam River basin has been considering for many years to minimize damages caused by flooding. The flood hazard zoning map is one of the indispensable tools to provide information about hazard and risk levels in a particular area and to perform the necessary preventive and preparedness procedures. The multicriteria decision analysis based on geographic information systems is used to build a flood hazard map of the study area. The analytic hierarchy process is applied to extract the weights of six criteria affecting the areas where are prone to flooding hazards, including rainfall, slope, relative slope length, soil, land cover, and drainage density. The results showed in 91.32 % (20103.83 km2) of the basin located in the moderate hazard zones to very high hazard zones. Accordingly, this study also determined 4 vulnerability levels to agricultural land including low, medium, high, and very high. About 94% of the total area of agricultural land in the basin are classified into moderate to the very high hazard of flood vulnerability. The paper presents a method that allows flood risk areas in the Lam River basin to receive information about flood risks on a smartphone, making them more aware.