Report

Showing 121 - 130 of 430 publications

System-Wide Submerged Aquatic Vegetation Model for the Chesapeake Bay

A predictive model of submerged aquatic vegetation (SAV) biomass is coupled to a eutrophication model of the Chesapeake Bay. Domain of the model includes the mainstem of the bay as well as tidal portions of the major embayments and tributaries. Three SAV communities are modeled: Zostera, Ruppia, and freshwater. The model successfully computes the spatial distribution and abundance of SAV for the period 1985-1994. Spatial distribution is primarily determined by computed light attenuation. Sensitivity analysis to reductions in nutrient and solids loads indicates nutrient controls will enhance abundance primarily in areas that presently support SAV. Restoration of SAV to areas in which it does not presently exist requires solids controls, alone or in combination with nutrient controls

Download publication

View details

Validation and Application of the Second Generation Three Dimensional Hydrodynamic Model of Chesapea

The validation and subsequent application of the current three dimensional numerical hydrodynamic model of Chesapeake Bay is presented. The numerical model solves conservation equations for water mass, momentum, salinity, and heat on a boundary-fitted grid in the horizontal plane. The vertical grid is Cartesian. A finite-difference solution scheme is employed such that vertically-averaged equations are first solved to yield the water surface elevations. These are then utilized in the computation of the barotropic portion of the horizontal pressure gradient in the internal mode. Model validation was accomplished by demonstrating the model's ability to reproduce observed data over times scales ranging from tidal to seasonal periods. After validation, the model was applied to simulate bay hydrodynamics for the 10 years of 1985-1994. These results were used to drive the three-dimensional water quality model of Chesapeake Bay, which is discussed in a companion paper.

Download publication

View details

Animal Nutrition Technology Exchange - Proceedings

During the past several years, considerable attention has been directed at the potential environmental impacts of agriculture in the Chesapeake Bay Watershed. A primary focus has been on the potential nutrient loadings to surface and groundwater resulting from animal agricultural sources. There is an emerging body of science-based information on the formulation of animal rations that have the potential to cost-effectively achieve the objectives of producers and also result in potential reductions in the nutrient content of manures at the point of excrement. The Chesapeake Bay Program's Agricultural Nutrient Reduction Workgroup planned a technology exchange of the latest advances in animal nutrition and the ability of these advances to provide cost-effective tools to reduce the nutrient content of animal waste at the point of excrement.

Download publication

View details