Background and objective Iran is prone to various natural disasters including floods. The location of zones at risks of floods is necessary for making optimal decisions for its management. This study aims to locate the zones with flood risk in the Lavasanat watershed using the fuzzy logic model. 
Method In this research, the most important factors affecting floods, including precipitation, slope, land use, distance from waterways, elevation, and lithology, were considered for flood risk zoning. These data were classified and weighted based on the opinions of 30 experts in the fields of geography, natural resources, and civil engineering. A questionnaire was prepared and distributed among them, and they were asked to weigh each factor between 0 and 1. Then, based on the fuzzy logic model, flood zoning maps were prepared in the ArcGIS software. To eliminate the limitations of fuzzy multiplication and sum models, a fuzzy gamma operator of 0.9 was used for flood risk zoning. In the final prepared maps, the study area was divided into five zones in terms of flood risk: Very high risk, high risk, moderate risk, low risk, and no risk (safe).
Results The results showed that the very high-risk zone covered 11.8% of the area, the high-risk zone covered 11.3%, the moderate-risk zone covered 26.7%, the low-risk zone covered 30.2%, and the no-risk zone covered 20%.
Conclusion More than 23% of the region is in zones at high and very high risk of floods. These zones are mainly located around the main waterway. In urban and rural planning and construction in the study area, the requirements for flood prevention and risk mitigation, including the consideration of flood retention and storage areas, should be taken into account.