During my time at Dahlem, I served as a co-examiner for a thesis that compared SplashTool’s results with those from a topographic flow path analysis and a detailed hydrodynamic analysis.
Ms. Gies’ thesis, titled “Comparative Analysis of the Application of Different Methods and Tools for Determining Heavy Rainfall Hazard Maps,” utilized data from an ongoing project in North Rhine-Westphalia and compared the results. Here are the key findings:
- Despite the different methodological approaches, the analysis with SplashTool agrees in terms of the classification of hazard classes and the extent and location of terrain depressions and flow paths in most areas
- Since in the analysis with SplashTool the entire water volume is applied to the terrain model at the beginning of the iteration, the flow paths determined via SplashTool tend to show a slightly larger spatial extent than the flow paths and flood extents determined via hydrodynamic analyses
- The topographic flow path analysis partly depicts unrealistic flow scenarios. Flow paths end too early or are continued too far, the size of the depressions is largely dependent on the previously definable fill level. Hydrodynamic analyses or analyses with SplashTool are generally preferred over the classic topographic flow path analysis due to the more meaningful results.
The following images from the bachelor’s thesis show exemplary visualizations for a subarea of the project
[1]: Gies, Ann Katrin: Comparative Analysis of the Application of Different Methods and Tools for Determining Heavy Rainfall Hazard Maps. Bachelor’s thesis at Darmstadt University of Applied Sciences, Department of Civil and Environmental Engineering, August 2022