Coastal Processes Analysis for Vilano Beach, St. Johns County, FL Taylor Engineering, Inc. Hande...

Coastal Processes Analysis for Vilano Beach, St. Johns County, FL

Taylor Engineering, Inc.Hande Caliskan, M.Sc.

Christopher Bender , Ph.D., P.E., D.CEMichael Krecic, P.E.

U.S. Army Corps of Engineers, Jacksonville District, FLJason Engle, P.E.

OVERVIEW• Project Description

o Purposeo Project Site

• Study Approacho GenCade SMS Interfaceo Data

• Calibration/Verificationo Procedureo Results

• Sensitivity Analysis• Summary and Results

PROJECT DESCRIPTION

PURPOSE

• USACE Jacksonville District is conducting a Hurricane and Storm Damage Reduction Study

• The GENESIS Model will provide erosion rates for beach nourishment alternatives

PROJECT SITE

STUDY APPROACH

Regional Contour

Initial Shoreline

GENESIS Grid

Wave Stations

R-64

R-69

R-74

R-79

R-84

R-89

R-94

R-99

R-104

R-109

R-114

R-119

DATA

• Florida Coastal Forcing Project (FCFP) Wave Data for Saint Johns County, FL

• FCFP Data at every 5th nearshore station

• FDEP Historical MHW and Beach Profile Data

CALIBRATION

R-84Small MHW

Shoreline Change

Large Volume Change

R-84

R-114

Small MHW Shoreline Change

Large Volume Change

-125

-100

-75

-50

-25

0

25

50

75

100

0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000 55000 60000 65000

Distance from R-63 (ft)

Sh

orel

ine

Pos

itio

n C

han

ge (

ft)

Measured Shoreline Change

Calibrated Model Shoreline Change

Shoreline Change Calculated fromMeasured Volume Change

Project Area

SENSITIVITY ANALYSES

Parameter Range Model Value

Time Step 0.25 – 2.00 hr 0.25 hr

D50 0.1 – 0.5 mm 0.2 mm

Berm Height 7 – 9 ft 9 ft

Depth of Closure 20 and 25 ft 20 ft

K1 0.5 – 0.75 0.75

K2 0.25 – 0.4 0.4

Model Parameters

SUMMARY AND RESULTS

• The shoreline change modeling component of the St. Johns County, Florida Hurricane and Storm Damage Reduction Feasibility Study developed and calibrated a GENESIS model for the study area (R-84 in South Ponte Vedra Beach southward to R-121 in Vilano Beach north of St. Augustine Inlet).

• The study applied the GENESIS model within the GenCade regional sediment management tool developed by the USACE ERDC.

• The calibrated and verified GENESIS model results agree well with measured beach volume changes during the calibration period (July 1986 to January 1999).

• The model produces reasonable agreement with measured volume changes during the verification period (January 1999 to August 2007)

• Additional model simulations documented the calibrated and verified GENESIS model sensitivity to selected model parameters.

QUESTIONS???