Water Overlay: Difference between revisions
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The calculations performed by the | The calculations performed by the Water Overlay are influenced by many kinds of geographical information present in the project area. For any given location, [[terrain]], [[construction]]s and other features can influence either the initial state of the simulation or how water flows in a given area. | ||
Furthermore, the Water Overlay features a number of overall settings which can be configured for the hydrological calculations and its results. These settings do not have a geographical or temporal element to them, and are fixed values relevant for the simulation as a whole. | Furthermore, the Water Overlay features a number of overall settings which can be configured for the hydrological calculations and its results. These settings do not have a geographical or temporal element to them, and are fixed values relevant for the simulation as a whole. | ||
Revision as of 14:12, 29 April 2019
A Water Overlay is an overlay for which results are calculated by the Water Module. The Basic theory of the Water Module in the Tygron Platform is an implementation of a 2D grid based shallow water model based on the 2D Saint Venant equations. The module is further enhanced with infiltration, evaporation, groundwater flow and hydraulic structures. Its calculations form a simulation of an arbitrary amount of time, during which water is allowed to move.
To perform the calculations, the project area is divided into a grid of cells. Each cell has a specific quantity of water and specific hydrological parameters based on the data in the project. The total time which should be simulated is divided into discrete timesteps. Per timestep, each cell communicates with its adjacent cells to exchange water, based on its water level, surface height, current flow direction and other factors. Accuracy and reliability is obtained by dividing the project area and simulation time into sufficiently small cells and steps, at the cost of more computation time.
The final results of the calculation can be inspected, as well as intermediate snapshots of the hydrological situation during the simulation, known as timeframes.
Variants
The Water Module can be called upon by adding one of the following overlays to a project. Each variant has a number of parameters tuned to best fit specific use-cases.
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Rainfall Overlay | provides insight into the water stress and impact caused by (excessive) rainfall |
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Flooding Overlay | provides insight into water stress and impact caused by breaches in levees or other sources causing excessive water inflow |
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Groundwater Overlay | provides insight into long-term processes of water flow both on the surface and underground |
Results
With a Water Overlay, one can generate different kinds of results. For further information about these outcomes, see also results and result types.
How-to's
- Add and remove an overlay
- Configure a Water Overlay
- Use a Water Overlay
- Edit an overlay legend
- Combine with Subsidence Overlay