In the context of climate change and increasingly frequent flash floods, rainwater management is becoming crucial to protect cities from flooding.
Rainwater management should be based primarily on maximizing the retention of rainwater on site. The question arises – how can comprehensive preventive measures for flood protection be planned at local government level?
Table of Contents
Hydrodynamic Modelling – Input Data Collection and Processing
Modern digital methods make it possible to precisely identify areas at risk, which is essential for spatial planning, civil protection and infrastructure design. Hydraulic and hydrodynamic models are used for this purpose, which we organize in HydroBIM using HEC-RAS and SCALGO software.
The basis of an effective hydraulic model is accurate input data. The software works from detailed numerical DEM (Digital Elevation Model) terrain models. This data allows the creation of a realistic surface map, which forms the foundation for further analyses.
The software allows the integration of meteorological data. Precipitation information – both forecast and historical – is another element of the analysis.
Rainwater Management – Analysis of Surface Flows
Using the 1D and 2D modelling functions, we analyse how water moves through the area, taking into account surface shape and precipitation. In the context of flash floods, this allows us to assess which areas are most likely to flood.
We analyse runoff paths and show where water accumulates. This is particularly important in urban conurbations, where infrastructure often cannot keep up with heavy rainfall.
The software allows us to simulate various rainfall scenarios and enables us to identify hot spots. This enables engineers to quickly assess risks and design appropriate countermeasures.
Drainage Modelling
One of the most important elements of flash flood analysis is drainage modelling. HEC_RAS and SCALGO offer advanced tools for simulating runoff scenarios, such as rainfall of varying intensity and duration. This makes it possible to accurately predict how different levels of rainfall will affect water flow in a specific area.
In the context of flash floods, the software used in HydroBIM allows extreme situations to be modeled, for example rainfall with a probability of occurrence of 1%, the so-called 100-year rainfall. The software shows where the water will accumulate, what areas will be flooded and what the flow velocities will be. Analysis of this data is essential for risk assessment and the preparation of plans to protect infrastructure and residents.
Dynamic visualizations show how the situation on the ground is changing in real time. SCALGO Live also enables the integration of the modelling results with other GIS tools to facilitate further analysis and action planning.
Assessment of Retention Capacity
The scenarios can include options that take into account different types of protective infrastructure, such as dykes, retention systems or barriers. The analysis of the results shows how these solutions reduce the risk of flash floods.
In practice, the results of the analysis make it possible to assess the effectiveness of existing retention basins and to optimise their capacity in the context of future investments. On this basis, it is also possible to plan additional protective measures, such as the construction of new retention facilities, the reconstruction of drainage systems or the introduction of changes in land use.
This is what happened in the municipality of Wielopole Skrzyńskie, where HydroBIM experts confronted the local government’s assumptions with the data obtained from the model, so that the municipality’s retention development plan could be made more realistic.
Countermeasures Planning
On the basis of analyses and simulations, planners and engineers can determine where best to locate drainage systems, retention basins, drainage ditches or culverts. The software allows different land-use options and their impact on rainwater management to be simulated.
For urban areas where the risk of flash floods is particularly high, hydrodynamic modelling supports urban optimization by identifying hot spots where enhanced protection is needed.
The model also provides information on where natural flows can be reshaped in a way that minimizes flood risk. For example, the analysis can indicate where it is worth creating buffer zones to absorb excess water, or where to introduce green areas to improve retention.
Different Scenarios Simulation
One of the biggest advantages of modelling is the ability to quickly compare multiple rainfall scenarios and design decisions. Real-time simulations allow a variety of land-use options to be tested and their impact on the risk of flash floods to be examined.
The scenarios can include options that take into account different types of protective infrastructure, such as dikes, retention systems or barriers. Analysis of the results shows how these solutions affect the distribution of water in real time.
Visualization of Results and Reporting
One of the most important strengths of the software used in HydroBIM is its ability to generate clear and detailed visualizations of hydrological modelling results.
In the context of flash floods, understanding the results of the analysis by decision-makers, designers and the local community is fundamental. The visualizations are easy to interpret. This makes it easier for non-technical people to understand the risks and evaluate proposed remedial engineering solutions.
The reports are valuable when presenting the analysis results to stakeholders such as local authorities, developers or local communities. By integrating with other GIS tools, results can be easily transferred and integrated into larger water management projects. Visualizations can be directly shared with project teams, local authorities and emergency management services, resulting in improved stormwater management.