IMPROVED SCIENCE AND DECISION SUPPORT FOR MANAGING WATERSHED NUTRIENT LOADS
Description:
The proposed research addresses two critical
gaps in the TMDL process: (1) the inadequacy of presently existing receiving
water models to accurately simulate nutrient-sediment-water interactions and
fixed plants; and (2) the lack of decision-oriented optimization frameworks
for managing nutrient loads to achieve multiple water quality objectives.
To advance understanding of sediment-water nutrient releases, we will test
the hypothesis that rates of phosphorus release are predictable from the dynamics
of iron release and iron speciation in the bottom waters, and that these in
turn are governed first by oxygen and then by nitrate concentrations. We will
also determine the stoichiometry and final products of nitrogen reduction/iron
oxidation. These new results, along with existing scientific research on attached
plants, will be integrated into a watershed/receiving water model that will
be applied and tested on the Aberjona River/Upper Mystic Lake watershed. The
watershed/receiving water model will then serve as a part of a decision-support
system (DSS) that represents the second component of this research. The decision-support
component will allow managers and stakeholders to rapidly develop different
management scenarios, explore the decision space to identify least-cost solutions
and integrate uncertainty into their considerations.
Record Details:
Record Type:PROJECT(
ABSTRACT
)
Start Date:01/20/2003
Completion Date:01/19/2006
Record ID:
57808
Keywords:
WATER, WATERSHEDS, SEDIMENTS, MACROPHYTES, DECISION SUPPORT, STAKEHOLDERS, CHEMISTRY, BIOLOGY, PHYSICS, HYDROLOGY, LIMNOLOGY, MODELING.,
Related Organizations:
Role
:OWNER
Organization Name
:TUFTS UNIVERSITY
Citation
:Medford
State
:MA
Zip Code
:2155
Project Information:
Approach
:Seasonal measurements of surface water chemistry and biology
and whole lake input-output fluxes of phosphorus and nitrogen will be made for
the Upper Mystic Lake. In addition, detailed vertical profiles will be sampled
for the lake's water column. The profiles will include the nitrogen/argon ratio,
nitrous oxide, and carbonate species (an approximation of total respiration,
in the absence of methane fermentation). In addition to particulate and dissolved
phosphorus we will measure iron (II) and total iron oxyhydroxides, reduced sulfur
species and methane. These measurements will be used to calculate electron balances,
to confirm that nitrogen redox and iron redox reactions are quantitatively coupled,
and to identify and quantify specific key mechanisms governing nutrient dynamics.
The results will then be used to parameterize and test a submodel of sediment-water
exchange and phosphorus speciation in the water column, including surface complexation
on iron oxyhydroxides. The submodel, along with an attached plant model will
be integrated with a seasonal, eutrophication model of the lake. This model
will be tested using the seasonal data.
Genetic algorithms (GA) using multiple objectives will serve as the optimization
tool for the decision support component of this research. The DSS will consist
of a series of linked simulation models (a GIS-based watershed model and the
improved eutrophication model) that will be interfaced with the GA solver and
a graphical user interface (GUI). Based on collaboration with a group of stakeholders,
environmental, social, and economic indicators and criteria will be developed
for use as objective functions within the DSS. We will also assemble data on
the options and costs for watershed nutrient management including data on the
costs and effectiveness of Best Management Practices, sediment management (e.g.,
dredging, capping, and re
Cost
:$749,179.00
Research Component
:Water and Watersheds
Project IDs:
ID Code
:R830654
Project type
:EPA Grant