Water area (Subsidence Overlay)
Water areas are areas of which the water level is managed by a water authority. Water levels have to be kept high enough such that subsidence is minimized but low enough such that agriculture can flourish. When subsidence occurs, the subsidence model supports the mechanism of indexation in which water levels are automatically lowered to keep the ground water levels at a similar level.
|m + datum
|The datum height of the water level in the Water Area.
|When Indexation is non zero, the water level is automatically adjusted each simulation year, depending on the calculated subsidence. Indexation may range from 0 (0%) to 1 (100%).
|m + datum
|The new datum height of the water level in the Water Area as a result of indexation in response to subsidence.
- In the subsidence models, water levels of water areas only influence the ground water level indirectly. Automatic adjustments of water levels, by indexation, do not always lower the ground water level in the same amount.
- The subsidence terrain keys can be overridden by overlapping Subsidence areas. Water areas can also be Subsidence areas at the same time.