OSCILLATIONS OF SEMI-ENCLOSED WATER BODY INDUCED BY HURRICANES Yuan-Hung Paul Tan Jiin-Jen Lee July 1, 2010 University of Southern California

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

Introduction The hurricane-induced oscillation (so called storm surge) of bays, harbors, and lakes can have a direct effect on beach and coastal communities. Chevron plant flooded in Pascagoula, MississippiPascagoula, Mississippi by Hurricane KatrinaHurricane Katrina Cargo ship and boats aground at Bayou La Batre, Alabama, after Hurricane KatrinaHurricane Katrina

Introduction Inundation in both estuarine tidal flats and riverine flood planes due to the storm surge can cause casualties and property damages. Flooding in Venice, LouisianaVenice, Louisiana Debris pile near Pass Christian, Mississippi, showing empty foundation slabs

Introduction Researchers have developed various analytical and numerical models based on the depth- averaged, non-linear shallow-water (NLSW) equations. Finite-volume method (FVM) is applied to solve the depth-averaged, non-linear shallow-water (NLSW) equations for this research. A Typical CV and the Notation used for a Cartesian 2D Grid

Motivation Storm surge built up in Lake Pontchartrain during Hurricane Katrina. Consequently, several catastrophic breaches happened in Lake Pontchartrain region. Because of levee breaches, over 700 people lost their life in New Orleans. 17 th Street Canal Breach North Breach, London Avenue Canal

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

Depth-Averaged, Non-Linear Shallow Water Equations (NLSE)

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

Hurricane Katrina (adopted from NNVL)

Hurricane Katrina (based on Knabb, Rhome, & Brown 2006)

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

Lake Pontchartrain (adopted from NASA)

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

Introduction of Model Verification The intensive field measurement data by IPET is used for comparison with the present simulation. The meteorological data to generate Hurricane Katrina is adopted from IPET report. Due to breaches and/or overtopping of dikes, water flows out of Lake Pontchartrain through three (3) canal entrances for model verification.

8 Selected Sites for Model Verification Bayou La Branche Pass Manchac Midlake Little Irish Bayou London Avenue Canal Orleans Avenue Canal IHNC 17th Street Canal

Water Surface Elevations at 3 Selected Sites A B C A CB

Model Applications The FVM model is applied to study the hurricane- induced oscillations in 4 scenarios: 1: Katrina tracking on its original route. 2: Katrina tracking on 36 km west of its original route. 3: Katrina tracking on 72 km west of its original route. 4: Katrina tracking on its original route with reduced forward speeds.

Map Showing 3 Routes

N-S & E-W Cross Sections

Hurricane Katrina Tracking on Route 1

Water Surface Elevation at 17 th Street Canal

Water Surface Elevation at Lake Pontchartrain (Scenario 1) W E

Water Surface Elevation in S-N Cross-Section

Water Surface Elevation in W-E Cross-Section

Hurricane Katrina Tracking on Route 2

Water Surface Elevation at 17 th Street Canal

Water Surface Elevation at Lake Pontchartrain (Scenario 2) W E

Water Surface Elevation in S-N Cross-Section

Water Surface Elevation in W-E Cross-Section

Hurricane Katrina Tracking on Route 3

Water Surface Elevation at 17 th Street Canal

Water Surface Elevation at Lake Pontchartrain (Scenario 3) E W

Water Surface Elevation in S-N Cross-Section

Water Surface Elevation in W-E Cross-Section

Hurricane Katrina Tracking on Route 1 with Reduced Forward Speeds Scenario 4: Katrina with reduced forward speeds

Water Surface Elevation at 17 th Street Canal

Water Surface Elevation at Lake Pontchartrain (Scenario 4) E W

Water Surface Elevation in S-N Cross-Section

Water Surface Elevation in W-E Cross-Section

Risk-Based Design and Analysis The major application of the finite-volume method (FVM) model is to assist the design of the water-front structure surrounding the semi- enclosed water body. The computational results generated by the present FVM model can help the planners to determine the optimal size of the hydraulic structures.

Risk-Based Design and Analysis

Contents Introduction Depth-Averaged, Non-Linear Shallow Water Equations Hurricane Katrina Lake Pontchartrain Model Verification & Applications Conclusions

The magnitude of the oscillation varies with the different storm paths and forward speeds of hurricanes at each specific location around the lake. The floods and the accompanying damages to New Orleans can be much severe if the forward speeds of Hurricane Katrina are reduced.

Thank You! & Questions?