Hydrologic analysis of flow and transport for the Everglades DPM experiments

Flow and transport of sediment and phosphorus through the low-gradient wetlands of the Everglades, FL were characterized using hydrologic, biological, geomorphic, and biogeochemical data as inputs to several types of simulations. The data were collected in the DPM (Decompartmentalization Physical Model) experimental high-flow facility in the central Everglades, FL. The DPM includes wetlands, canals, and levees bordering Water Conservation Area 3A (WCA-3A) to the northwest and Water Conservation Area 3B to the southeast. We simulated the hydrologic flow of WCA-3A water though several closely spaced culverts beneath the L-67A levee into DPM as flow spreading in a radial pattern through the wetland. The radial flow simulations characterize interactions between total flow entering though culverts beneath the L-67A levee, flow spreading angle in the wetland, vegetation roughness, water slope, water depth, and water flow speed in the wetland. Also, we used the one-dimensional transport model (OTIS) model to simulate the conservative transport of water along a central flow path through the wetland using specific conductivity as an environmental tracer. Reactive transport simulations with OTIS used observations of suspended sediment concentration (SSC) and total phosphorus (TP) to quantify the rate of removal of suspended sediment and total phosphorus from flowing water. Gross primary productivity (GPP) and ecosystem respiration (ER) along the flow path was assessed by simulating transport and reactivity of dissolved oxygen using MATLAB scripts. Furthermore, at the downstream end of the DPM we made simple steady-state water and chemical mass balance calculations to assess water, suspended sediment, and total phosphorus leaving the DPM by transport though a downstream gap in the L67-C levee into WCA-3B.