How to generate an initialized groundwater situation
When working with the complete groundwater model of the Water Overlay, it is very likely that any initial configuration for groundwater is not actually the state of the groundwater "at rest", meaning that during the initial period of the simulation the groundwater will always flow to a different location into a more stable configuration. For example, an initial groundwater dataset may have a consistent groundwater level defined for a large plot of land, while the more natural situation may be that the water follows a curve due to the way water flows into and out of the ground.
The consequence of this phenomenon, especially for short simulations, is that groundwater will not yet have reached a natural state by the the time the main event of the simulation takes place, or even when the simulation ends. To compensate for this, it is possible to prepare the groundwater data by setting up and running a stationary calculation for groundwater, allowing it to settle, and using the (more natural and stable) result as the initial groundwater state for the actual calculation.
- Ensure that the Water Overlay has the groundwater mode set to "Complete".
- Ensure that the Water Overlay has data for groundwater set, if one is available.
- Ensure that the Water Overlay has a ground last value output.
- Configure the rainfall for the model to run stationary, for a period of multiple weeks.
- Recalculate the Overlay.
- Export the ground last value output of the Overlay as a GeoTIFF.
- Open the Water Overlay configuration wizard, and proceed to the groundwater step.
- Upload the exported GeoTIFF and set it as the groundwater data for the Water Overlay.
- Repeat the recalculate, export, and upload steps as often as desired, until the groundwater's stabilization time and effect is acceptable for your use-case.
- Ensure that the Water Overlay has the groundwater mode set to "Complete".
- Ensure that the Water Overlay has data for groundwater set, if one is available.
- Ensure that the Water Overlay has a ground last value output.
- Configure the rainfall for the model to run stationary, for a period of multiple weeks.
- Recalculate the Overlay.
- Add a new Groundwater Overlay
- Open the Water Overlay configuration wizard for this new overlay, and proceed to the groundwater step.
- Select the option "Select a Groundwater Depth Grid Overlay"
- Select the Ground water overlay you have calculated before.