Impact of Hurricanes on Nutrient Transport from Catchment to Coast:An Integrated Case Study of Mobile Bay and its Watershed

Northern Gulf Coastal Hazards Collaboratory Alabama Water Resources Conference5 September 2013

Hypothesis & Approach

• University of Alabama - Mississippi State University – University of South Alabama – University of Alabama Huntsville Louisiana State University

• Loosely coupled models – HSPF – WRTDS – EFDC – ADCIRC • Data Transfer – Analysis – Metadata – Data Extraction

Does the speed of a hurricane making landfall near Mobile Bay impact the nutrient distribution within the bay?

Seamless DEM, Land Use MODIS/GIRAS, Stream Network, Outlet Locations, River Discharge, Water Quality Concentration, Grids, Wind Models.

Loose Couple ModelHSPF – WRTDS – ADCIRC - HSPF

Visualization with CERA Visualization with SULIS

FUTURE

Simulocean

Pydap

Hypothesis & Approach

Technical Aspects

• Use of Multiple Models

• Transferring Large Text Files

• Processes are in series, output of one model is the input of the next model

• Scale and time issues

HSPF – Hydrological Simulation Program Fortran

Seamless DEM Land Use Datasets

WinHSPF

WRTDS – Weighted Regressions in Time Discharge and Season

USGS - NWISEPA - STORET

Data Graber / WUDEXT(Simulobot --> Future)

WRTDSConcentrations

V. Alarcon, J. Cartwright, W. McAnallyGeosystems Research Institute and

Northern Gulf Institute

A. Maestre, A. Ward, D. WilliamsonCivil Engineering and Biological Sciences

Output: Water Discharge Output: Nutrient Fluxes

Track of Category 4 and 5 Hurricanes that landed as Category 3+

Extreme Event AnalysisA. Maestre, A. Ward, D. Williamson

Civil Engineering and Biological Sciences

Slow Moving Storms (25+ inches)

SLOSH ModelHurricane Dennis (2005)

Output: Slow / Fast Storms

ADCIRC - The ADvanced CIRCulation model

HURRICANE DANNY 1997

ADCIRC

C. Kaiser, K. HuCenter for Computation and Technology

Output: Water Elevation in the Gulf of Mexico

HURRICANE IVAN 2004

Slow Hurricane Fast Hurricane

EFDC – Environmental Fluid Dynamics Code

Water Discharge

Gulf Water Elevation

EFDC

Output: Nutrient Distribution after a Slow and Fast Hurricane

Nutrient Fluxes (Total Nitrogen)

K. ParkMarine Sciences

EFDC – Environmental Fluid Dynamics Code

K. Park, A. Maestre, J. Cartwright

Information needed for EFDC simulationRiver discharge (QR) & TN load

Open BC

WindIC

landfall at 01:00 on 09/16 near Gulf Shores, AL

Ivan (2004)

landfall at 04:00 on 07/19 near Fort Morgan, AL

Danny (1997)

No peaks in QR and TN load associated with Danny

Peaks in QR and TN load associated with Ivan

Water and Nutrient Discharge into Mobile Bay

Max wind = 32.3 m sec-1

Max wind = 32.7 m sec-1

Wind Fields input into EFDC

: During equatorial tide: Large surges

: During tropic tide: Small surges

Water level in Mobile Bay during Hurricane Events

Points to Consider in Evaluating Hypothesis

- How to evaluate/interpret model and process (precipitation patterns, track, surge, etc…) interactions that control nutrient peak and distribution

- How to take into account of large rainfall during Danny (>932 mm on Dauphin Island)?

- Effect of interaction between tides and hurricane landfall time (e.g. during tropic vs. equatorial tide)

Things to try:- Run the model for a relatively long time period : 9/8-9/28 in 2004 for Ivan (landfall on 9/16) : 7/11-7/31 in 1997 for Danny (landfall on 7/19)

- Compare two hurricanes in terms of percentage of TN input

- How to make a fair comparison when there was no large surges during Danny?

Outcomes & Future Goals

• Created solutions for integrated modeling of hazards across multiple cyber-platforms.

• Experiment -- Interaction and collaboration among all NGCHC universities.

• Implement results from EFDC in a visualization tool (i.e., Sulis or CERA)• Start the transformation from “loose coupling” to “dynamic coupling”

models• Investigate use of the modeling system for further integrated

watershed and bay research.• Future proposals to NSF, NOAA, EPA, USACE

– Interior flood/surge modeling– Water quality hazards from flooding– Addition of ecosystem models to suite