Flood extent maps (FEM) and flood hazard maps (FHM) serve as legal instruments for spatial planning, decision-making, strategic flood risk planning, and public awareness, supporting sustainable and safe land use along the river corridor. This study aims to improve existing FEM and create FHM for the Sanica river, prone to frequent flooding. The existing FEM were developed using a 1D HEC-RAS model under steady-flow conditions, applying a single uniform Manning roughness coefficient along the entire river reach. The study presents the first application of an unsteady 2D HEC-RAS model along Sanica river, integrating LiDAR-based topography and updated hydrological data to derive FEM and FEH for common return periods. The final 2D hydraulic model was selected through calibration of seven variants of the Manning roughness coefficient, three lumped and four distributed, with the optimal configuration identified based on three goodness-of-fit measures. The comparison of 1D and 2D FEM shows close agreement in morphologically confined canyon reaches, while significant differences occur in river sections with floodplain inundation and dominant 2D flow. These results indicate that model dimensionality can be selected based on reach-scale morphology, enabling the use of 1D models in canyon sections to reduce computational time, while applying 2D models only where complex flow dynamics are present within the Sanica river study area.

Rapid urban development and increasing hydro-meteorological variability are creating new challenges for flood risk management in urban areas. In this context, the concept of a smart city offers opportunities to improve the understanding, prediction, prevention, and management of flood events through the integration of environmental monitoring, digital technologies, data, modelling, and decision-support systems. However, becoming a "smart city" in terms of flood management requires more than the introduction of individual technological solutions. This paper explores what Sarajevo would need to develop an effective smart flood management system. The analysis considers the key components required for such a system, including reliable and spatially distributed meteorological and hydrological monitoring, real-time data acquisition and transmission, integration of heterogeneous data sources, high-resolution geospatial databases, hydraulic and hydrological modelling, flood forecasting and early warning, and decision-support tools for emergency response. Particular attention is given to the integration of existing monitoring and information systems and to the interoperability of data generated by different institutions and infrastructure systems. The paper further considers the importance of defining clear institutional responsibilities, data-sharing mechanisms, communication channels, and procedures for translating technical information into timely decisions. Rather than proposing a single technological solution, the paper identifies the essential components and their interconnections that should form the basis for Sarajevo's transition towards smart flood risk management. The proposed framework can serve as a basis for assessing the current level of preparedness and identifying priorities for future investments in monitoring, modelling, digital infrastructure, institutional capacity, data exchange, and warning communication.

Univerzitet u Sarajevu – Građevinski fakultet

The river channel cut into an alluvial substrate constantly adapts to changes in water flow and sediment transport. This paper presents a new approach to determine the magnitude of channel deformation based on the definition of dimensionless spatial parameters of channel deformation. The new approach’s applicability is evaluated by experimental studies on the Željeznica River in the Sarajevo Field in central Bosnia and Herzegovina. The morphological changes of the channel over a period of ten years were analyzed using dimensionless parameters of the channel geometry. A numerical analysis of changes in the channel of the Željeznica River was carried out using a mathematical model and a selected equation for sediment transport. Sensitivity analysis of the model parameters for channel deformation and statistical reliability analysis of the numerical model showed a good agreement between the modeled and observed values of channel deformation parameters during the analyzed period.