Case study contributed by Michael Callaghan, PhD, P.Eng – Senior Applications Engineer, Aquanty
Aquanty is a leading-edge water resources science and technology firm specializing in predictive analytics, simulation and forecasting, research services, and IoT. Aquanty’s solutions and services are deployed globally across a broad range of industrial sectors including; agriculture, oil and gas, mining, watershed management, contaminant remediation, and nuclear storage and disposal. Aquanty’s flagship platform, HydroGeoSphere, is a class leader in fully integrated three-dimensional surface/subsurface modeling.
What Is an Integrated Surface-Subsurface Hydrologic Cycle Model?
HydroGeoSphere (HGS) is a three-dimensional control-volume finite element simulator which is designed to simulate the entire terrestrial portion of the hydrologic cycle. It uses a globally-implicit approach to simultaneously solve the 2D diffusive-wave equation and the 3D form of Richards’ equation.
The basis for HGS’ integrated computation is multiple 1D, 2D, 3D ‘domains’ that interact with each other, including:
- a 2D overland flow domain,
- a 3D subsurface flow domain that can include separate discrete fractures and dual permeability domains,
- as well as 1D surface flow channels,
- 1D subsurface tile drains,
- and 1D water wells.
Data intensive model output for the hydrologic cycle benefits from the flexibility of Tecplot 360 for visualization, which often requires plotting of multiple domains simultaneously and in 3D.
“We chose Tecplot 360 because of the quality of the plots. We need to present our results to clients, and for that plot quality there is no substitute to Tecplot 360.”
– Michael Callaghan, PhD, P.Eng, Senior Applications Engineer, Aquanty
Visualization of Surface Water – Groundwater Interaction
Simulating groundwater-surface water interaction in complex topography such as hummocky terrain has traditionally been viewed as a significant challenge to the hydrologic modelling community, for example so-called fill and spill behavior.
However, with HGS, the complex processes by which water movement is influenced by the combination of surface topography and highly variable subsurface hydrostratigraphy or preferential flow pathways can be readily reproduced.
In the example shown in Figure 2, precipitation is falling on an upland area which then initiates overland flow, filling, and spilling of surface depressions. The Tecplot 360 animation illustrates depression-focused groundwater recharge occurring beneath the depressions, with both a perched water table and a fractured aquitard influencing sub-surface water movement.
Figure 2. Visualization of surface water-groundwater interaction.
Flood Inundation Visualization
HGS models may range across a number of scales from centimeters to meters to kilometers to 100’s of kilometers. Use of an unstructured finite element mesh makes this possible.
Tecplot 360’s inherent flexibility with unstructured grids makes it a very useful visualization tool across many scales of problems.
In this application, HydroGeoSphere is being used to recreate the Southern Alberta, Canada flooding that occurred in June 2013. The simulation results presented in Figure 3 depict a flood pulse derived from basin scale hydrologic simulations being routed across a local scale model of the City of Medicine Hat, Alberta, Canada. LiDAR-derived topography was used as input for this model, and results show excellent agreement between simulated and observed high water marks.
Figure 3. Flood inundation visualization.
The above visualization cases are made possible with Tecplot 360. HGS is highly integrated with Tecplot ecosystem using a powerful post-processing tool to directly produce results in Tecplot file formats. Tecplot 360 is an essential tool for everyday 2D data plotting, high quality 3D model visualization, results inspection and evaluation.