Flooding is a natural disaster which affects thousands of riversides, coastal and/or urban communities causing severe damages. River flood mapping is the process of determining inundation extents and depth by comparing historic river water levels with ground surface elevation referenced. This paper aims to map flood geohazard areas under the influence of the Uruguay River, Itaqui city (Southern Brazil), using calibration Digital Elevation Model (DEM), historic river level data and Geoprocessing techniques. The annual maximum for years of 1942 to 2017, of fluviometric temporal series records of Uruguay River were linked to Brazilian Geodetic System using geometric levelling and submitted the statistical analysis. The DEM was calibrated with Ground Control Points (GCP) of high vertical accuracy based on post-processed high-precision GNSS surveys. Using the temporal series statistical analysis results, was assessed the spatialisation of flood hazard classes on the calibrated DEM and validated. Finally, was visually compared the modelling of the simulated flood level versus flood area on satellite image, which both were registered on the same date. The free DEM calibration model indicated high correspondence with GCPs (R 2 = 0.81; p < 0.001). The calibrated DEM showed a 68.15 % improvement in vertical accuracy (RMSE = 1.00 m). Were determinate 5 classes of flood hazards: extremely high flood hazard; high flood hazard; moderate flood hazard; low flood hazard; and non-floodable. The flood episodes with return time of 100 years were modelled with 57.24 m altimetric level. Altimetric levels above 51.66 m have high potential of damaging, mainly affecting properties and public facilities in the city northern and western peripheries. The assessment of the areas that can potentially be flooded can help to reduce the negative impact of flood events by supporting the process of land use planning in areas exposed to flood geohazard.