An Important Combination for Improving the Determination of Flood Zones: Remote Sensing Techniques and Hydraulic Models

The computation of flood-affected zones plays a pivotal role in risk management and land use planning. These zones can be identified by applying remote sensing techniques, digital elevation models, and implementing hydrological and hydraulic models. Remote sensing can detect changes in water surface levels over time using optical and SAR images. Digital elevation models are essential for defining the topography and morphometry of water bodies. Often, these techniques are employed to determine water levels associated with recorded events, representing a need for estimating water levels associated with different return periods. Subsequently, hydraulic models must be integrated with remote sensing techniques to create reliable models for sizing engineering projects related to return periods, which can vary from 5 to 5 years depending on the cost-benefit relation of a selected hydraulic structure. This research presents a framework for utilizing technological tools to combine remote sensing techniques with hydraulic models to correlate recorded flooding events and estimate flooding for different return periods. A case study in Santa Cruz de Lorica, Colombia, is assessed to demonstrate the advantages of the combined techniques discussed in this study. The flooding in the case study is delineated using optical and SAR images from different sources. A detailed discussion about using images applied to flooding zones is presented.