Draft Strategy 2-6-09Revised 3-10-09

RMP Modeling StrategyRMP Modeling Strategy

John Oram

Jay Davis

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Draft Strategy 2-6-09Revised 3-10-09

IntentIntent

• To develop a capacity to predict the effect of different management alternatives on – loads from watersheds,

– the recovery of contaminated areas on the Bay margin,

– the recovery of the Bay as a whole

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Draft Strategy 2-6-09Revised 3-10-09

ApproachApproach

• To develop conceptual and numeric models of the physical, chemical, and biological processes governing the fate of water, sediment, and pollutants of concern in San Francisco Bay and its associated watersheds

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Draft Strategy 2-6-09Revised 3-10-09

Question 1 : Bay MarginsQuestion 1 : Bay Margins

• What is the contribution of contaminated Bay margins to impairment in the Bay and what are the projected impacts of management actions to the Bay's recovery?

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Draft Strategy 2-6-09Revised 3-10-09

Question 2 : Bay RecoveryQuestion 2 : Bay Recovery

• What patterns of exposure are forecast for major segments of the Bay under various management scenarios?

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Draft Strategy 2-6-09Revised 3-10-09

Question 3 : Small Tributary LoadsQuestion 3 : Small Tributary Loads

• What are the projected impacts of management actions on loads or concentrations of pollutants of concern from the high-leverage small tributaries?

• Where should management actions be implemented in the region to have the greatest impact?

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : CoordinationStrategy : Coordination

• Establish a Bay Area Modeling Forum that will– guide agencies and NGOs in the selection, use, and

interpretation of models for describing sediment-water relationships in fluvial and tidal systems

– improve communication and coordination of local modelers and stakeholders

– reduce duplication of efforts

– improve the overall quality of modeling products

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Bay & Margins ModelStrategy : Bay & Margins Model

• Develop a flexible grid model capable of implicitly allowing for the interaction of fine-scale processes occurring at the Bay Margins with the larger-scale processes of the Bay proper

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Bay & Margins ModelStrategy : Bay & Margins Model

• What is a flexible grid anyway?– An approach to allow increased resolution in areas of concern

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Bay & Margins ModelStrategy : Bay & Margins Model

# cells 44,148

cell size Curvilinear 50 m to 1.3 km

dt (min) 1.0 - 0.1

Curvilinear Grid

Delft3d grid from P. Barnard (USGS)

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Bay & Margins ModelStrategy : Bay & Margins Model

SUNTANS grid of Puget Sound

Unstructured Grid

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Bay & Margins ModelStrategy : Bay & Margins Model• Some Model Options

– Multibox• + Good for hypothesis testing• - Limited spatial/temporal resolution• - Limited ability to calibrate/validate• - Limited sediment capabilites

– 3D Commercial : Delft3D, Mike, TRIM, UnTRIM• - Licensing can be costly• + Set-up often less complex than open-source• + ‘Package Deal’ - includes pre- and post-processing software• + Technical support is available• - ‘Black Box’

– 3D Open-Source : ROMS, SUNTANS, …• + Freely available• +/- State-of-the-art• +/- Community Support• - Set-up can be challenging• +/- Time is largest expense

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Bay & Margins ModelStrategy : Bay & Margins Model

• What is SUNTANS?– Stanford Unstructured Nonhydrostatic Terrain-

following Adaptive Navier-Stokes Simulator

– ‘Next generation’ of coastal models

– Co-developed in SF Bay by Stanford and UC Berkeley

– Open-Source

– Includes water, sediment, contaminant capabilities

– Accounts for tidal wetting/drying

– Ocean boundary condition can be driven by ROMS

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Draft Strategy 2-6-09Revised 3-10-09

Strategy : Local WatershedsStrategy : Local Watersheds

• Develop models of key watersheds over the next three years with the goal of developing a regional model (or set of models)

• Watersheds will be identified by SPLWG and Small Tributaries Strategy Team– These groups will provide project oversight as well.

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Draft Strategy 2-6-09Revised 3-10-09

Model ProposalModel Proposal• What: Development of a highly-resolved three-

dimensional model of South Bay• Who: Mark Stacey (UCB), Rusty Holleman (UCB), Ed

Gross (Consultant), John Oram (SFEI)• Why: Project would provide support for a UCB graduate

student to continue development of South Bay model and would help insure that development is relevant to RMP objectives.

• Specifics: Aim is to develop flexible grid of South Bay with emphasis on 1 or 2 tributaries (e.g., Guadalupe) and a Bay margin site (e.g., San Leandro Bay). Model will be useful for answering questions related to flushing times and exchange processes (e.g., what is influence of margin on Bay?).

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