Coastal Hazard Assessment for the Lowermost Mississippi River Management Program

Transcription

1 Coastal Hazard Assessment for the Lowermost Mississippi River Management Program USACE ERDC Coastal and Hydraulics Laboratory Mary Cialone Chris Massey Norberto Nadal USACE Mississippi Valley Division Ty V. Wamsley State of the Coast Conference, June 1, 2018

2 COASTAL RESTORATION AND THE STORM SURGE HAZARD South Louisiana communities face risk from coastal storm surge and waves as well as from riverine and precipitation event flooding. Restoration activities can have system wide impacts on flood risk that must be evaluated as part of a comprehensive restoration plan

3 OBJECTIVES Build a State of Louisiana/USACE cooperative and collaborative coastal and river hazard assessment capability that will inform multiple efforts for increasing community resilience while restoring the ecosystem. Special focus on the interaction of storm surge and riverine flows and how alterations to the Mississippi River may alter flood risk.

4 PROBABILISTIC COASTAL HAZARD ASSESSMENT 4 Climatology Characterization of Storm Climate (Forcing) Tropical Cyclones (Synthetic) StormSim CHS Development of JPM Storm Set Climate and Hydro Modeling PBL Cyclone Model (Wind and Pressure Fields) WAM (Regional) Water level (storm surge, astronomical tide, SLC) Wave height, period, direction Wind speed, direction, currents ADCIRC CSTORM-MS Coupler STWAVE (Nearshore) CSTORM Response Statistics Combined Joint Probability Annual Exceedance Probability Confidence Limits StormSim File Name

5 DEVELOPMENT OF SYNTHETIC TCs JPM Parameterization with a Hybrid Discretization Approach to provide Optimal parameter space and spatial coverage. = f= Response ( xˆ ) f ( x0, p, rmax, v f, θ ) Structured/Uniform discretization (Resio 2007) θ = heading direction Δp = central pressure deficit Bayesian Quadrature (BQ) discretization (Toro 2008) rmax = radius of maximum winds vf = translational speed A complete new suite of storms will be developed for Louisiana

6 ERDC s COASTAL STORM MODELING SYSTEM Application of high-resolution, highly skilled numerical models in a tightly integrated modeling system with user friendly interfaces Readily relocatable and flexible forcing features. Plug-n-Play design for expandable and upgradeable system. Next Generation Workflow Provides for a robust, standardized approach to modeling coupling. Used for establishing the risk of coastal communities to future occurrences of storm events. 6

7 CSTORM COUPLING FRAMEWORK One unstructured finite element circulation mesh A single instance of ADCIRC Information to Exchange One or more wave grids/meshes ζ, u, v Multiple instances of STWAVE/WW3 CIRC Wave WAVE τ x,τ y For consistency use the same winds and bathymetry Circulation (can be passed via coupler) Synchronize both time and spatial frames of reference. CIRC Timeline WAVE Snaps 7

8 COMPREHENSIVE MESH/GRIDS UPDATE Louisiana mesh and grids will be updated with the latest bathy/topy and levee heights collected by CPRA.

9 CSTORM PRODUCTION SYSTEM The CSTORM Production System (CSTORM-PS) makes use of standard Linux/Unix tools (bash scripting) and readily available open source software, Python The production system allows for Rapid preparation of necessary input files for individual CSTORM-MS production runs (Reduces chances for human error) Execution of the simulation Execution of post-processing programs (for statistics) Execution of CSTORM Visualization and Report tool Efficient file storage and archival Setup Simulation Prep ADCIRC for Parallel Execute CSTORM Post-Process, Visualize & Stats Compress Outputs Tar Results Together Archive Results 9

10 EXAMPLE MAX SURGE RESULTS Surge and wave results will be obtained for all simulations and available for statistical and other analyses

11 HAZARD CURVES Hazard curves will be developed coast wide to support a wide range of efforts to quantify coastal storm hazards and how restoration activities may influence the coastal hazards. *Example from Coastal Texas Study

12 12 LEVERAGE OTHER STUDIES South Atlantic Study Coastal Texas Study

13 USACE ERDC Coastal and Hydraulics Laboratory Probabilistic Coastal Hazard Assessment (PCHA) Studies North Atlantic Coast Comprehensive Study (NACCS) Virginia to Maine Statistical reanalysis (v.2) to be completed in 2018 Coastal Texas Study Completed in 2018 South Atlantic Comprehensive Study Phase I (2019), Phase II (2021) South Florida to North Carolina including Puerto Rico and USVI Mississippi to South Florida RESTORE study will provide Louisiana with a state of the art hazard assessment consistent with rest of Nation

14 MISSISSIPPI RIVER ALTERATIONS Changing Course was a design competition to reimagine a more sustainable Lower Mississippi River Delta. The coastal hazard assessment system will be applied to quantify storm surge propagation up the river associated with different Mississippi River channel configurations under various river stages and how that influences risk for communities.

15 COASTAL HAZARDS RAPID PREDICTION A primary objective of the Gulf Coast Ecosystem Restoration Council is to restore the ecosystem and the economy of the Gulf Coast Region. The economy of the Gulf Coast Region is greatly enhanced if communities in coastal Louisiana have a capability to more rapidly and more accurately predict storm surge hydrographs. StormSim-CHRP is software that provides rapid prediction of coastal hazards for operations and emergency management. Hurricane parameters are read from NOAA 6-hour update web service and used to predict waves and water levels in seconds. Underlying Gaussian Process Metamodels (GPM) are being developed and trained on hurricane-response data from Gulf of Mexico. This is the first metamodeling system to predict time series.

16 SUMMARY State of Louisiana/USACE cooperative and collaborative coastal and river hazard assessment capability will be developed that informs efforts for increasing community resilience while restoring the ecosystem. Special focus on the interaction of storm surge and riverine flows and how alterations to the Mississippi River may alter flood risk. Information developed as part of this study will be invaluable for informing CPRA restoration efforts and planning and development of future Coastal Master Plans.