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Develop a seasonal water balance for the entire Everglades; and use the water balance to estimate pre- and post-disturbance flows into the ridge and slough landscape.
In general, these research recommendations will address many of the important gaps in our understanding of the role of flow, as identified in the White Paper and elsewhere in the scientific literature. It is important that a flow research program be carefully designed and focused to provide useful information in a timeframe relevant to the restoration. Immediate attention should be given to the development of alternative conceptual models of the formation and maintenance of the ridge and slough landscape (White Paper higher priority recommendation 2). This could be achieved at least partially by convening a workshop on peat accumulation and decomposition. As recommended in the White Paper, the most compelling models should be used to develop research hypotheses and questions that can be used to guide the design of a research program. Careful attention should be paid to research on well-studied peat landscapes with similar features, such as the wetlands of the Okavango Delta in Africa (McCarthy et al, 1986, for related research see <http://www.wits.ac.za/science/geology/vango_research.htm>) and the patterned peatlands of the boreal zone (Glaser et al., 1981; Glaser, 1983; Glaser and Janssens, 1986), though these are not entirely analogous.
As is stated in the White Paper, a research program on flow in the Everglades should include a study of the paleoenvironmental history of the Everglades. It should also include the following: measurements of flow and sediment transport and accumulation, development of carbon budgets, monitoring and analysis of remotely sensed data on landscape geometry, and development of seasonal water balances for Everglades landscapes. All studies should be designed to address questions and hypotheses associated with the leading conceptual models of landscape formation and maintenance, primarily focusing on ridges, sloughs, and tree islands. Whenever possible, studies should be paired between relatively intact landscapes and degraded ones.
Regarding flow and sediment, the committee agrees with the White Paper that research should be conducted to better understand processes. It is particularly important to measure flow and sediment flux during extreme events. This will be challenging and expensive, and should be co-located with sites where other related research on the ridge and slough landscape is occurring. The White Paper’s recommendation of “synoptic measurements of flow...conducted over short time scales and large spatial scales in order to quantify ranges of flow velocity and direction and to delineate major flow pathways” may provide useful information. However, barring technological advances, such measurements will be very expensive to make and may have limited value in view of the likely importance of large events in the system.
Simple measurements of organic sediment accumulation can also provide useful information on sediment transport. For example, the hypothesis that maintenance of the ridge and slough pattern requires transport of organic sediment can be tested readily by measuring accumulations of this sediment at major barriers to flow, such as in the canals flanking Alligator Alley and the Tamiami Trail.
In addition to collecting remotely-sensed images of the ridge and slough landscape, water and soil surface elevations should be monitored on selected portions of the landscape. Topographic mapping at a spatial resolution of 1-3 m and vertical accuracy of 0.1-0.25 m would allow analysis of scale-dependent landscape pattern, microtopography and geomorphic processes. Airborne LIDAR (Light Detection and Ranging) offers a good option for such monitoring, although there are technical challenges to operational monitoring using this technology (Ritchie, 1996; Marks and Bates, 2000; Mertes, 2002; Schmugge et al., 2002). Such data could be tied to the sparser grid of high-precision elevation control points