Mechanical Engineering MS Thesis Defense by Mr. Ranjoy Barua
When: Monday,
December 18, 2017
10:00 AM
-
12:00 PM
Where: Textiles Building 101E
Description: Mechanical Engineering MS Thesis Defense by Mr. Ranjoy Barua
DATE:
December 18, 2017
TIME:
10:00 a.m. 12:00 p.m.
LOCATION:
Textile Building, Room 101E
TOPIC:
Assessing Water Quality Improvement Strategies for Cockeast Pond, Westport, MA Using RMA2/RMA4
ABSTRACT:
Estuaries provide critical habitat, nursery grounds, and food to a variety of wildlife, including numerous species of migratory birds and fish. Estuaries also provide significant economic and ecological benefits, contributing tens of billions of dollars in goods and services annually across numerous economic sectors. However, in recent years, estuaries around the globe have become impaired, as total nitrogen (TN) concentrations in many systems have increased, degrading habitat, and causing the estuaries and their surroundings to lose their ability to sustain life. In this thesis, I examined different remediation scenarios to improve the water quality of one such estuary, Cockeast Pond. Cockeast Pond is a salt pond in Westport, MA that has become nitrogen enriched due to watershed inputs and poor tidal flushing. Studies of this estuary have documented the effects of nitrogen enrichment, mainly high rates of primary production and periodic dissolved oxygen depletion. The RMA2/RMA4 hydrodynamic model, an industry standard developed by the U.S. Army Corps of Engineers, was used to test different management scenarios for reducing TN in the system. First, the model was run for 1-year using time dependent inputs with present and altered nitrogen loading scenarios. Next, since previous work has shown that TN concentrations in Cockeast Pond differ for spring vs. summer conditions, separate steady state simulations were run to predict long-term spring and summer conditions independently. Decreased watershed nitrogen loading, increased tidal flushing, and the incorporation nitrogen removal by oyster aquaculture were each examined as possible remediation approaches for reducing water column TN levels. Scenarios were run addressing each remediation approach separately, as well as in combination to see which combinations can achieve target TN reductions. Findings suggest TN was not reduced below 0.5 mg/l during summer using the combined scenario consisting of 50% reduction in septic system discharge, 100% reduction in lawn fertilizers, and widening of the pond's tidal channel by a factor of two. However, the addition of two million oysters with this scenario did reduce the TN to below the threshold limit during the critical summer period. These results can be used to guide possible restoration efforts of the Cockeast Pond estuary, including non-traditional alternative approaches such as oyster aquaculture.
ADVISOR:
Dr. Miles A. Sundermeyer, Professor, SMAST / Department of Estuarine and Ocean Sciences
COMMITTEE MEMBERS:
Dr. Miles A. Sundermeyer, Professor, SMAST / Department of Estuarine and Ocean Sciences
Dr. Geoffrey Cowles, Associate Professor, SMAST / Department of Fisheries Oceanography
Dr. Brian L. Howes, Professor, SMAST / Department of Estuarine and Ocean Sciences
Open to the public. All MNE students are encouraged to attend.
For more information, please contact Dr. Miles Sundermeyer (msundermeyer@umassd.edu, 508-999-8892).
Thank you,
Sue Cunha, Administrative Assistant
Department of Mechanical Engineering
508-999-8492
scunha@umassd.edu
DATE:
December 18, 2017
TIME:
10:00 a.m. 12:00 p.m.
LOCATION:
Textile Building, Room 101E
TOPIC:
Assessing Water Quality Improvement Strategies for Cockeast Pond, Westport, MA Using RMA2/RMA4
ABSTRACT:
Estuaries provide critical habitat, nursery grounds, and food to a variety of wildlife, including numerous species of migratory birds and fish. Estuaries also provide significant economic and ecological benefits, contributing tens of billions of dollars in goods and services annually across numerous economic sectors. However, in recent years, estuaries around the globe have become impaired, as total nitrogen (TN) concentrations in many systems have increased, degrading habitat, and causing the estuaries and their surroundings to lose their ability to sustain life. In this thesis, I examined different remediation scenarios to improve the water quality of one such estuary, Cockeast Pond. Cockeast Pond is a salt pond in Westport, MA that has become nitrogen enriched due to watershed inputs and poor tidal flushing. Studies of this estuary have documented the effects of nitrogen enrichment, mainly high rates of primary production and periodic dissolved oxygen depletion. The RMA2/RMA4 hydrodynamic model, an industry standard developed by the U.S. Army Corps of Engineers, was used to test different management scenarios for reducing TN in the system. First, the model was run for 1-year using time dependent inputs with present and altered nitrogen loading scenarios. Next, since previous work has shown that TN concentrations in Cockeast Pond differ for spring vs. summer conditions, separate steady state simulations were run to predict long-term spring and summer conditions independently. Decreased watershed nitrogen loading, increased tidal flushing, and the incorporation nitrogen removal by oyster aquaculture were each examined as possible remediation approaches for reducing water column TN levels. Scenarios were run addressing each remediation approach separately, as well as in combination to see which combinations can achieve target TN reductions. Findings suggest TN was not reduced below 0.5 mg/l during summer using the combined scenario consisting of 50% reduction in septic system discharge, 100% reduction in lawn fertilizers, and widening of the pond's tidal channel by a factor of two. However, the addition of two million oysters with this scenario did reduce the TN to below the threshold limit during the critical summer period. These results can be used to guide possible restoration efforts of the Cockeast Pond estuary, including non-traditional alternative approaches such as oyster aquaculture.
ADVISOR:
Dr. Miles A. Sundermeyer, Professor, SMAST / Department of Estuarine and Ocean Sciences
COMMITTEE MEMBERS:
Dr. Miles A. Sundermeyer, Professor, SMAST / Department of Estuarine and Ocean Sciences
Dr. Geoffrey Cowles, Associate Professor, SMAST / Department of Fisheries Oceanography
Dr. Brian L. Howes, Professor, SMAST / Department of Estuarine and Ocean Sciences
Open to the public. All MNE students are encouraged to attend.
For more information, please contact Dr. Miles Sundermeyer (msundermeyer@umassd.edu, 508-999-8892).
Thank you,
Sue Cunha, Administrative Assistant
Department of Mechanical Engineering
508-999-8492
scunha@umassd.edu
Topical Areas: Faculty, General Public, Students, Students, Graduate, University Community, College of Engineering, Mechanical Engineering, Lectures and Seminars