Coastal and subcoastal floodplain wet heath swamp

Coastal and subcoastal floodplain wet heath swamp – Hydrology

• Wet
• Dry

Click on elements of the model or select from the tabs below

• Hydrology
• Geomorphology
• Fauna
• Flora
• Nutrients
• Associated habitat types
• Fire
• Photos

Coastal floodplain heath swamps typically occur where there is enough rainfall, local watershed run-off, overbank flow and/or groundwater discharge to maintain a seasonally high water table.

Water tables in heath swamps dry out seasonally, creating hydrological conditions that are favourable for the growth of heath vegetation. Areas that have a more constant water table tend to have more grass, herb and sedge growth.

The hydrology of coastal floodplain heath swamp habitats is related to a site’s topography, substrate type and position within the catchment. Climatic factors (especially those related to rainfall) also play a significant role in the regularity, seasonality, duration and amount of water entering and leaving the wetland.

Water Inputs

Floodplain wetlands can be flushed with water from overbank flow, streams leading directly to the site, sheet flow across the floodplain, rainfall, run-off from the local watershed, hyporheic flow and from other types of groundwater, or a combination of these sources.

If groundwater table levels and substrate permeability permit, this can lead to more constant systems. This wetland habitat type can play a role in groundwater recharge/discharge. An important point to note is that hyporheic flow and other groundwater flow tend to be clear (not turbid), compared to surface water flow.

Water Outputs

Evaporation, transpiration and groundwater recharge can lead these systems to dry out, often completely (see dry model).

Overbank floods move out onto the floodplain or back to the channel, connecting the wetland habitat to other wetland habitats in the floodplain. Water may also flow out to the ocean via distributary channels, depending on topography.

Last updated: 22 March 2013