MODELING

The U.S. Geological Survey (USGS) is conducting market research to determine the availability of qualified businesses capable of providing a model that computes transport of water, nutrients and plankton between aquatic habitats and land by tidal and river currents as described in the attached Statement of Work. This sources sought announcement is not a request for quote or proposal and the Government is not committed to award of a purchase order or contract pursuant to this announcement. The information resulting from this market research is simply for planning purposes to assist the Government in determining its acquisition strategy. The Government will not pay for any costs incurred in the preparation of information for responding to this notice.The North American Industry Classification System (NAICS) code 541990, All Other Professional, Scientific and Technical Services, and associated size standard $15M revenue applies to this announcement. All responsible sources may submit a

capabilities statement detailing the ability of their service to meet the statement of work included with this announcement.Responses to this announcement shall only be accepted through electronic mail addressed to dallan-loucks@usgs.gov, and must be uploaded and received in their entirety no later than 27 June 2018/1500 ET. Responses submitted by hardcopy or the FedConnect web portal or the FedConnect Message Center shall not be accepted or considered.Statement of WorkModeling to Support Restoration of the Sacramento-San Joaquin Delta Ecosystem 1.0 INTRODUCTION This SOW describes services of an environmental engineering firm to build and apply a model to compute transport of water, nutrients and plankton between aquatic habitats and land by tidal and river currents. The model is an essential component of a science plan funded by the Delta Science Program to assess how historical landscape changes in California's Delta ecosystem have altered biological productivity at the food-web base. That information will inform design of actions to restore lost habitats and the ecological functions they provided in the past.2.0 BACKGROUNDIn October 2015 the San Francisco Estuary Institute (SFEI) and USGS organized a workshop funded by the Delta Science Program (DSP) and USGS to develop a science plan for assessing how landscape changes after the early 19th century altered biological productivity in the Delta ecosystem. Motivation for the science plan is to identify connections between landscape configuration and productivity at the food-web base to guide new programs of habitat restoration. One component of the science plan is a collaboration between USGS, SFEI, and Resources Management Associates (RMA), where RMA would take the lead in developing and applying a box model to simulate tidal movements of water between channels and marsh plains and to compute primary productivity of microalgae carried by those water movements. There is no existing modeling tool for making these computations under different landscape configurations of land and water. 3.0 SCOPEEstuarine systems like California¿s Delta are not composed of static, isolated habitat types, and the importance of transport of primary production between habitat types, e.g., from marshes to open water areas, has been shown in estuarine systems worldwide. The magnitude of primary production is affected by not only the habitat size, but also the connectivity between habitat types, ultimately affecting the food supply to consumer organisms. Thus, the science plan includes a component to construct a two-box model as a research tool for learning how tidal and riverine transport influences system primary production and its availability to aquatic consumers. Specifically, this modeling component will address two central questions: Question 1: What can simple box models teach us about how water movements between marsh and open water affect the magnitude of phytoplankton production? Question 2: What can simple box models teach us about how shape, size and connection type of marsh and open water areas affects the magnitude of phytoplankton production? 4.0 APPLICABLE DOCUMENTSThe full science plan, including complete description of the modeling component, is available in the workshop report published by SFEI: Robinson, A.; Richey, A.; Cloern, J. E.; Boyer, K. E.; Burau, J.; Canuel, E.; DeGeorge, J. F.; Drexler, J. Z.; Howe, E. R.; Kneib, R.; et al. 2016. Primary Production in the Sacramento-San Joaquin Delta: A Science Strategy to Quantify Change and Identify Future Potential. SFEI Contribution No. 781. (available at http://www.sfei.org/documents/primary-production-sacramento-san-joaquin-delta-science-strategy-quantify-change-and). A summary providing the broad context and motivation for the science plan was published in San Francisco Estuary and Watershed Science:James E. Cloern, April Robinson, Amy Richey, Letitia Grenier, Robin Grossinger, Katharyn E. Boyer, Jon Burau, Elizabeth Canuel, John F. DeGeorge, Judith Z. Drexler, Chris Enright, Emily R. Howe, Ronald Kneib, Anke Mueller-Solger, Robert J. Naiman, James L. Pinckney, David Schoellhamer, Charles Simenstad. 2016. Primary Production in the Delta, Then and Now. San Francisco Estuary and Watershed Science, 14(3):1-9. (available at http://dx.doi.org/10.15447/sfews.2016v14iss3art1).RMA¿s 3D model and its application to simulate tidal and riverine flows in the historical Delta are available at: Andrews, S. W., E. S. Gross, and P. H. Hutton. 2017. Modeling salt intrusion in the San Francisco Estuary prior to anthropogenic influence. Continental Shelf Research 146: 58-81.5.0 TECHNICAL REQUIREMENTSThe strategy for addressing the above questions will include three tasks. 5.1 Task 1: Develop a multi-box model design and implement the modelThis task will establish the water quality modeling requirements for simulating primary productivity. It will establish the set of constituents, required parameters, and required boundary conditions for the model. It will determine the interactions between the hydrodynamic inputs, sediment dynamics, and the USGS nutrient-phytoplankton-zooplankton model. The box model design will accommodate two boxes (marsh and channel). Different sets of model parameters will be developed to represent a range of archetypal marsh/channel configurations representative of the historical Delta. Numerical implementation of the final design will be done in a manner that is convenient for use by USGS and other researchers (Matlab or Python code). Initial implementation will focus on phytoplankton, but the model design will be extendable to consider other primary producer groups in the future.Model representations of each channel-marsh configuration will require the following hydrodynamic parameters derived from existing 2D (RMA Bay-Delta Model) and 3D (RMA San Francisco Estuary UnTRIM model) simulations: Lookup tables describing the relationships between water elevation, volume for the channel and marsh areas, and average depth of water Time Series at control volume boundaries and within control volumes including Tidal range Exchange between marsh and channel Net flow through the channel Tidal exchange between the channel and neighboring channels Bed shear stressControl volumes will be identified on the existing 2D and 3D model geometries that correspond to archetypal marsh/channel configurations. Time series of exchange flows at control volume boundaries as well as point, area average, and volume average values within control volumes will be extracted from these existing model results. Simulation periods will be selected from a library of model runs maintained by RMA. Focus of this effort is on differentiating the level of primary productivity that might be expected with different marsh configurations as opposed to evaluation of a full range of hydrologic conditions. Periods will be selected to represent typical conditions present between spring and fall with dry or below normal conditions. Sufficient hydrodynamic data will be extracted from existing model simulations to characterize spring/neap variation and moderate flow/low flow periods.5.2. Task 2: Configure the multi-box model for different channel-marsh configurations This task will configure the two-box model for a set of channel-marsh configurations selected by the research team, and then simulate representative flow conditions (historical, modern, wet and dry conditions). Data extracted from past simulations with 2D and 3D models of the Delta will be used to establish the volumetric and exchange parameters for each configuration of the box model. For each configuration, the model will be run for 2-5 annual simulation periods with flows ranging from dry to wet. These flow conditions are expected to influence net flows through the marsh-channel system, depth of water, turbidity, or exchange between channel and marsh. Results will be compared to evaluate differences between configuration and flow on phytoplankton primary production.5.3 Task 3: ReportingThe contractor will document the modeling approach, the application and configuration of the test model, and summarize the two-box model results in: (1) a peer-reviewed journal article, and (2) a SFEI report. Both publications will involve collaboration with SFEI, USGS and other associated authors, and will be organized and coordinated by SFEI. A brief discussion of the process used in developing the modeling approach, interpreting the output, and lessons learned will also be included.6.0 DELIVERABLESDeliverables for this project will include: documented source code for the two-box primary production model example model data sets for the selected channel-marsh configurations contributions to publications describing the model, channel-marsh configurations, and model results.Milestones for this effort will include the following: Identification of the channel-marsh configurations to be tested Design of the multi-box model and selection of programming language Application of the multi-box model for selected channel-marsh configurations Contribution to the group peer-reviewed manuscript and SFEI report.The product will be a numerical model of nutrient transport and phytoplankton growth and transport between habitat types. Contact Information: Allan-Loucks, Dana Office Address :USGS OAG SACRAMENTO ACQUISITION BR.MODOC HALL, CSUS3020 STATE UNIVERSITY DRIVE EASTSACRAMENTOCA95819-6027USLocation: USGS - All Offices Set Aside: N/A