Hydrology component:

1) The large coastal islands of the southwest Everglades appear to be hydrologically disconnected from upstream freshwater inflows, but not to groundwater. Their response to sea level rise is still a matter of debate. - Surface water hydrology of the large islands found on the southwest coast of Everglades National Park (those lying between the tidal rivers) appears to respond independently of upstream hydrology or even the river hydrology. However, there does appear to be a similarity in groundwater hydrology across the coastal zone of the Everglades.

Relevance to resource managers: Management of the coastal marshes and prairies on these islands will depend on prescribed fire rather than hydrologic manipulation.

This study supports the second bullet under "Milestones, Products, and Payoffs" of Question 8.2 of the "Strategic Plan for the Climate Change Science Program Final Report, July 2003". (See section starting with "Reports describing the potential consequences of global....")

Figure 1H. Relationships of stage anomalies at gauge P33 in central Shark River slough in Everglades National Park and sediment porewater salinity anomalies at three locations downstream from P33. The data have been adjusted by subtracting the monthly mean from each monthly observation. Thus, above average stage (positive anomalies) lead to below average salinities (negative anomalies). Site SW1 is located approximately 20m from the edge of the Harney River, a large tidal distributary of Shark River Slough. SW3 is 150m inland from SW1. SW5 is located 350m away from the river and is in a sawgrass prairie. [larger image]

2) Sediment surface elevation in freshwater and saltwater wetlands respond differently to water level changes. As stage decreases in freshwater wetlands, sediment elevation increases, whereas, when stage decreases in saltwater wetlands, elevation also decreases.

Figure 2H. Relationship between water level (stage) change and sediment surface elevation for freshwater and saltwater wetlands. The relationships are opposite. [larger image]

Relevance to resource managers: All wetlands in the Everglades are NOT equal! The response of wetlands to the hydrologic restoration of CERP will vary depending on location along the salinity gradient.

This study supports the second bullet under "Milestones, Products, and Payoffs" of Question 8.2 of the "Strategic Plan for the Climate Change Science Program Final Report, July 2003". (See section starting with "Reports describing the potential consequences of global....")

3) The berm removal project on the C-111 canal was only partially successful at restoring water levels in downstream marshes. - Our analysis indicates that the removal of the berm has resulted in pre-canal marsh water levels in the western portion of the C-111 basin, but not the eastern portions. Marsh water levels in the Highway Creek drainage are still below those of the pre-canal period.

Relevance to resource managers: Further structural modifications to the C-111 levee may be required to adequately redistribute surface water and flow to downstream marshes.

This study supports the second bullet under "Milestones, Products, and Payoffs" of Question 8.2 of the "Strategic Plan for the Climate Change Science Program Final Report, July 2003". (See section starting with "Reports describing the potential consequences of global....")

4) Marsh water columns in the Florida Everglades experience a daily turnover that is driven by the pattern of daily solar heating and nighttime cooling. The spring and fall vertical mixing of the water column in lakes and ponds has a profound influence on nutrient dynamics and productivity. We found that the shallow water column of the Everglades marshes experience a daily turnover (mixing) that is driven by rapid temperature changes. This mixing extends into the upper layers of the sediment. And is dependent on water depth.

Relevance to resource managers: This mixing of the water could have profound impacts on the cycling of nutrients and contaminants (e.g. mercury) in the Everglades. The dynamics of this process will most likely be altered by increasing water depths and flows under the current restoration scenario, but we do not know by how much.

This study supports the second bullet under "Milestones, Products, and Payoffs" of Question 8.2 of the "Strategic Plan for the Climate Change Science Program Final Report, July 2003". (See section starting with "Reports describing the potential consequences of global....")