Hydrodynamics

Hydrodynamics2019-09-16T12:36:19-04:00

Evaluating the Impact of Hydrologic Alterations on Salt Marsh Sustainability in a Changing Climate

Project Title: Evaluating the Impact of Hydrologic Alterations on Salt Marsh Sustainability in a Changing Climate

Project Partners: Cape Cod Mosquito Control Project, Louisiana State University, National Park Service, United States Fish and Wildlife Service, Rachel Carson National Wildlife Refuge, United States Geologic Survey, Waquoit Bay National Estuarine Research Reserve, Woods Hole Oceanographic Institution

Coastal managers are faced with the challenge of managing marsh hydrology in a way that meets human health needs, optimizes ecosystem services, and supports sustainability. In New England this includes accounting for the effects of ditches that were dug decades ago in 90% of the region’s salt marshes.

Ditches increase marsh drainage and reduce the spatial extent of shallow pools that may represent physical loss of buried soil carbon. However, efficient drainage may reduce the long-term sustainability of marshes by altering below ground biogeochemical and physical processes in a way that results in subsidence and lowered marsh elevation. Managers, restoration practitioners, and scientists at the Waquoit Bay National Estuarine Research Reserve, Woods Hole Oceanographic Institution, U.S. Geological Survey, U.S. Fish and Wildlife Service, National Park Service, and the Cape Cod Mosquito Control Project have expressed a need to understand the tradeoffs of hydrologic management strategies (i.e., ditch remediation, density, maintenance) and identify actions that will achieve user-specified outcomes— such as drainage, maintaining elevation, and carbon burial.

This project is a collaboration between scientists and end users to develop decision-support tools for marsh hydrological management strategies that promote sustainability and delivery of valuable ecosystem services under future sea level scenarios.

Products:
FACT SHEET: Project Overview
WHOI Website: Marsh Sustainability & Hydrology
Marshes, Mosquitos & Sea Level Rise-Oceanus Magazine Video Link

Land–sea coupling and global-driven forcing: following some of Scott Nixon’s challenges

Project Title: Land–sea coupling and global-driven forcing: following some of Scott Nixon’s challenges

Date: 2015

Principal Investigator(s): Valiela, I. & Bartholomew, M.

Summary: Adjoined watershed–estuary–coastal ecosystems are coupled by biogeochemical and hydrodynamic processes, as Scott Nixon repeatedly argued in his many contributions. Case histories from Waquoit Bay and the Pacific Coast of Panama, supplemented by information from other sites, make evident that the couplings that enable connectivity among spatially separate landscape units, while highly subject to detailed local contingencies, take place in every coastal zone, can be powerfully affected by human activities on land, and by global-scale forcings, as Scott Nixon often reminded us. Read full text…Estuaries and Coasts 38: 1189. doi:10.1007/s12237-01498083. https://link.springer.com/article/10.1007/s12237-014-9808-3

Development of Low-cost, In-situ, Precision Hydrodynamic Instrumentation for Measurement of Tides, Currents and Waves

Project Title: Development of Low-cost, In-situ, Precision Hydrodynamic Instrumentation for Measurement of Tides, Currents and Waves

PI: Vitalii Sheremet, University of RI, NOAA NMFS Research Fellow

Funding: NOAA NMFS Research Fellowship, WBNERR collaborative in-kind

Summary: An inexpensive current meter based on the drag principle is being designed and developed. It provides a simple, elegant, robust, and low-cost solution for measuring currents at the ocean bottom or from any fixed platform. Its operation is based on the drag law of a buoyant tethered cylinder in flowing water. Three-axis accelerometers measure tilts which are converted to a horizontal velocity vector. Special tethered attachment enables estimation of not only the magnitude but also horizontal direction of the current. The same accelerometers are also used to construct a simple stick-and-float tide gauge.

The performance of the instruments is being evaluated in field tests in Waquoit Bay and Nantucket Sound. Arrays of the instruments deployed for periods from days to months are used to record tidal and higher frequency oscillations in the Waquoit Bay. A dramatic double peaked flood (double height) tide arising from nonlinear interaction with bathymetry is studied. Strong seiches with periods of about 15-30 minutes are also recorded in some parts of the Waquoit Bay system.

Weather Data

Water Quality Data

Tides & Currents

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