Introduction: Flood is a natural disaster that threatens the lives of millions of people yearly. Obtaining the flood zone and consequently obtaining the flood zone maps with a specific return period for a reach is one of the important issues. Therefore, estimation of flood maps is required for accurate river engineering studies, flood control projects and planning to reduce the economic and social flood damages. In most parts of the world, hydraulic models are the best ones for flood inundation mapping. However, due to the lack of data and numerical problems, it is not possible to use them for hydraulic simulations. Different of these models, topographically based models such as HAND due to their simple structure and minimum data requirements are the best choice for data sparse regions. Hence, evaluating the performance of the HAND model, which relies solely on topographic features, is one of the objectives of the present project. Methodology: In this study, the flood maps are determined using the HAND model with a calibration based on satellite observations. Seimareh river is selected as a case study to challenge the performance of the model in relation to the observational data and HEC-RAS hydraulic model. In addition, the efficiency of HAND model in low and high flows compared with a 1D and 2D hydraulic model to evaluate the performance of the model in different flow conditions. Results and Discussion: The most important results can be summarized as follows: • The results obtained from the HAND model indicate that this model has the high potential for flood inundation mapping in Seimareh river. The similarity percentages of the estimated and observed flood extents are higher than 92%. Also, the average relative error (ARE) between HAND model and observed flood extents through the study reach is 8. 5%. • The results in Seimareh river show that changing the discharge value does not change the performance of HAND model and the model has a good capability compared to HEC-RAS model. Based on the findings, the similarity percentage of estimated (based on HEC-RAS) and observed flood extents is limited to 83%. The ARE value of HECRAS model in simulation of flood extents is 13%. • Despite the excellent performance of the HAND model in estimating the flood maps, in some parts of the study reach there are differences between the HAND model, satellite images, and the hydraulic model. The main reason of this discrepancy can be related to the extraction and using only one rating-curve for Seimareh river. Therefore, dividing the river into different segments, which contain similar roughness coefficient and river geometry, can significantly increase the performance of the model. • Hydraulic model compared to HAND has more error in estimating flood extents. The main reason for this can be related to important factors such as distance between cross sections, computational dimensions, numerical parameters used in the 1D and 2D hydraulic models (such as θ parameter and currant number), boundary conditions, computational time step and Manning roughness coefficient for each cross section. In general, more factors affect the performance of the hydraulic models and affect theirs outputs, while the HAND model experiences relatively better conditions in this regard. Conclusion: Flood inundation mapping (FIM) is one the key parts of river engineering and flood control studies. Therefore, using a reliable and robust method for calculation of FIM is paramount of importance. In this research, the applicability of a topographic-based method (HAND model) is investigated in Seimareh River. In addition, the performance of is compared with HEC-RAS model and observed flood extents. Findings clearly showed that the HAND model, in spite of having simple structure, performed better than HEC-RAS and estimated the FIM as well as observed flood maps. This model can be used in data sparse regions or large scale reaches in which setting up or running hydrodynamic models is a daunting and time consuming task. Finally, coupling HAND approach with flood warning models can be used as an applicable system for flood emergency management and flood control studies.