Natural and nature-based features (NNBFs) are becoming more prevalent in coastal resiliency and protection design as climate change threatens social, economic and environmental systems along the U.S. coast. However, planners need enhanced processes to predict and quantify their benefits prior to implementation.
To better incorporate these designs into numerical models, the U.S. Army Corps of Engineers (USACE) has developed an Engineering With Nature® toolkit for the Coastal Storm (CSTORM) Modeling System, enabling planners to test the hydrodynamic, ecologic and adaptive effects of NNBFs on coastal or estuarine environments.
“The EWN toolkit for CSTORM modeling is a graphic user interface, or GUI, that allows a numerical modeler to represent NNBFs digitally in existing numerical models and standardizes and streamlines the augmentation of those features into the modeling framework,” said Dr. Amanda Tritinger, a research hydraulics engineer with the U.S. Army Engineer Research and Development Center and assistant program manager for the USACE EWN initiative.
The initiative uses the intentional alignment of natural and engineering processes to efficiently and sustainably deliver economic, environmental and social benefits through collaboration. As projects are planned, USACE districts require a method for predicting the impact that EWN features — such as NNBFs — may have on the coastal resiliency of communities, quantifying changes to predicted values of storm surge, inundation and wave attenuation for various storm events if these features were implemented.
Traditionally, the process for bringing these features into numerical models has been cumbersome and expensive. The modeling requires manual integration into the bathymetry/mesh, entailing a high level of skill and a significant time commitment. Each time the feature is altered, the mesh must be rebuilt, causing significant time delays.
“This new tool lets you get a preview of what your meshed-in feature will look like,” said Tritinger. “It also lets you drag and drop multiple designs in one at a time and choose alternative ideas to see what could work and what doesn’t. I think it gives engineers the thumbs up to try something different. It’s more than just a tool -- it’s the chance to push the line of innovation on engineering design.”
The tool doesn’t only open the door to innovation, but also to efficiency.
“In recent studies with both the USACE Mobile District and Philadelphia District, what usually would have taken us two weeks to develop took two hours,” Tritinger said.
Standardization is an important key to the framework’s success. The CSTORM design team put a lot of effort into the literature review, working to consistently set the parameters of the numerical model.
“Before, you had to do this extensive literature review to figure out how to represent your features and the parameterization settings of your numerical modeling,” said Tritinger. “We’ve brought all the literature together and put it in one place in this GUI. It allows the user to see the metadata, where the numbers come from, and use their own expertise to adjust as needed.”
Interested districts can download the GUI by visiting the Aquaveo website or learn more information about the toolkit at the EWN website.
“There is also material on the EWN website supporting the toolkit,” Tritinger said. “I think that’s really important for actual application. It’s one thing to have the tool, it’s another to know how to use it. Hopefully this tool, and the documentation behind it, can empower the districts to quantify and understand effects of more resilient designs.”
As part of the EWN initiative, researchers hope to see more widespread usage of the EWN toolkit across the enterprise as the tool can be used to streamline mesh development in general for numerical modeling.
“I would highly recommend – even if you don’t have interest in NNBFs – to take a look, download it, and apply it to mesh development even outside the Advanced Circulation Model,” said Tritinger. “Because of the new workflow, you can develop a mesh and apply it to your own models. It does more than augment an NNBF into a numerical modeling framework. It can expand innovation on every project.”