RECOVER MAP 3.1.4.4 Determination of Sheetflow Hydrodynamic Properties

This work builds on the results of a series of surface water tracer experiments conducted by Drs. David Ho and Evan Variano from Columbia University. The tracer study was funded by the Critical Ecosystems Studies Initiative at Everglades National Park. The first phase of that study was just completed and this proposal is intended to provide hydrodynamic analyses of the field data with respect to ridge and slough processes.

Objectives
The objective of this study is to calculate hydrodynamic properties of large-scale sheetflow patterns in the ridge and slough habitat. The study will utilize field data already collected as part of the EverTREx tracer release experiments (http://duck-rabbit.ldeo.columbia.edu/everglades) in order to calculate hydrodynamic parameters of surface water flow, including advection rates and dispersion coefficients, Reynolds numbers and vegetative resistance. Results will be compared to values used in SFWMM calculations.
The analyses will be performed using 1) daily time series of tracer data collected along transects in the marsh, and 2) spatially explicit data showing the evolution of the tracer across the landscape over several sequential days of sampling. The analysis will focus on the calculation of parameters used in a set of standard hydrodynamic equations used to represent the physical processes of sheetflow. Unique methods of deriving these parameters utilizing Lattice-Boltzmann techniques will also be applied. The Lattice-Boltzmann solutions will be utilized to project animations of sheetflow patterns onto digitized aerial images of the ridge and slough habitat where the tracer releases were performed and for which suitable stage data are available.
The question this study will address can be stated as follows: â How do the hydrodynamic properties of sheetflow differ in degraded versus well-preserved areas?â
The product of this work will be a technical report containing a quantitative analysis and visualizations of sheetflow patterns in the marsh. This report will also provide a theoretical framework for linking the USGS EDEN water surfaces with large-scale sheetflow patterns that influence sediment transport and nutrient fluxes in relation to ridge and slough geomorphology. These analyses will provide a means to use the routinely monitored stage gradients, the current distribution of marsh vegetation community types, and the maps of the EDEN water surfaces to assess the effects of structural discharges and water management operations on sheetflow patterns in the ridge and slough.