Project Completed
May 24, 2020
Hugo Savenije
TU Delft
Tool for flexible model architecture in hydrological modelling

Appropriate modelling of hydrological processes requires flexible tools which are able to adapt to a system’s dominant characteristics and to the requirements of specific applications. However, current modelling practice is largely based on the application of fixed model architectures based on prior perceptions. As we shall illustrate, this hampers the progress of research and limits the effectiveness of practical applications. Our purpose is to develop a flexible modelling approach that can help hydrologists to understand the behaviour of a system, and practitioners to develop tailored solutions for specific problems. This approach will result in a toolbox where different model architectures can be created and tested with the available data. These architectures should be able to vary in complexity and encompass a large variety of hydrological conditions. We expect that this tool will allow us to address fundamental research questions for hydrological science, while at the same time it will be a practical tool for professional applications. Possible applications include the determination of an appropriate balance between model complexity and data availability, the understanding of the value of data for modelling, the investigation of appropriate ways to incorporate distributed information in the modelling process.



This project created an interface for the FLEX hydrological model. FLEX hydrological model allows us to choose flexible hydrological modelling structure, based on our understanding of catchment rainfall-runoff processes. The generic components of the FLEX model are reservoirs, lag functions and connection elements. The flux functions describing storage-discharge relationships, shape of lag functions, etc, are selected from a library of functions and can be used to hypothesize and build multiple alternative model structures. The end-users can select different generic reservoir and corresponding constitutive functions for interception reservoir, unsaturated reservoir, fast response reservoir and slow response reservoir. Moreover, lag functions, splitters and multipliers can also be used as generic components to build flexible models. FLEX model is implemented as a standalone Fortran-95 code, and is also integrated into the built-in model library in Petit Bateau. Hence, installing Petit Bateau gives you immediate access to FLEX. This also means we need to install Petit Bateau to run the FLEX model. The FLEX interface, coded by C#, can be used to easily and visually generate different model structures. After selecting the model structure in the interface, a configuration file for Petit Bateau can be atomatically generated. Modellers can flexibly choose their conceptual model to understand catchment rainfall-runoff processes, as simple as playing Lego bricks.

This project contains 5 files, including two PDF documents, two executable software, and the source code of the interface. The two PDF documents, “An exercise for FLEX_interface.pdf” and “Using flexible models within BATEA.pdf”, contain a couple of excercises instructing end-users to build their own model structures by the interface, and generate the configuration files for the Petit Bateau. The “BATEAU_DEMO.7z” contains the Petit Bateau software. And the “FLEX_interface.exe” is the executible file of the interface. “FLEX_interface_SourceCode.7z” is the source code of the interface.