Prototype 'digital twin' helps Enschede better predict groundwater

The municipality of Enschede had been concerned about extreme weather conditions for some time and was trying to improve groundwater control. The existing approach involving the use of movable barriers that can be opened and closed to control the drainage of groundwater, and therefore, its levels, was largely technical in nature but required constant monitoring of the groundwater level in order to be able to intervene in time.

For his Engineering Doctorate, Morales developed a digital twin representing part of Enschede’s city centre that analyses and predicts groundwater levels using measurement data. These forecasts help identify critical water-level thresholds in advance and recommend the optimal timing and actions for operating groundwater control barriers, enabling proactive responses before extreme droughts or heavy rainfall occur.

"During my EngD, I worked on a concrete social problem," says Morales. "That makes this programme different from a PhD: the goal is not just knowledge development, but application. In the end, this resulted in a usable prototype with a meaning."

The prototype is now working, and it includes a digital testing environment to understand the behaviour of the digital twin capabilities with digital versions of the control barriers, but full implementation may take a few more years. There are still several challenges. For example, making the predictions more accurate and for longer periods of time, as well as testing the prototype with physical barriers and its interaction with other systems to further understand its physical and environmental effects. Groundwater beneath Enschede is difficult to control, so no single solution can fix everything, but this prototype represents an important piece of the larger puzzle.

"The soil in Enschede consists largely of clay," Morales explains. Such soil has a high water-retention capacity, resulting in poor drainage performance and causing additional strain in drainage systems. Additionally, rapid, heavy rainfalls can further overwhelm drainage systems with excessive water volume and pressure, causing the water to reverse direction and making it come out of drains rather than properly draining. It’s similar to pouring water into a bottle through the top opening very quickly. Even though there is still space inside, the trapped air and limited outlet slow the flow, pressure builds up, and water spills out. In sewer pipes during extreme rainfall, wastewater behaves the same way: it cannot drain fast enough, so it is pushed back up through household drains or stresses underground pipes until they crack. To further improve the predictions of the digital twin, more data and additional tests are needed.

An EngD program is a two-year post-master's design program. In contrast to a PhD, which is mainly focused on developing new knowledge, an EngD is all about designing concrete solutions for complex social and technical issues, often in collaboration with external parties.

Rodrigoandrés Morales succesfully defended his thesis entitled. 'A Digital Twin for Ground Water Table Monitoring'. His supervisors were: Karin Pfeffer, Mila Koeva, Leon olde Scholtenhuis (faculty of ITC).