Coastal Modeling for Resilience: Taking Steps Ahead · 2 | Coastal Modeling for Resilience: Taking...

Coastal Modeling for Resilience:

Taking Steps Ahead

Picture: The Philadelphia Inquirer,

Clem Murray/AP

Picture: www.dailymail.co.uk

Sibtey HasanCoastal Engineer Dewberry, New York

1 | Coastal Modeling for Resilience: Taking Steps Ahead

Why do we need “Coastal” Resilience

Rising Sea levels

Coastal Storms

Coastal Erosion

What can be done?Coastal Resilience!

“Ideally, coastal communities and infrastructure

should be built far away from the coast to be

protected from these threats. But in reality, the

waterfront is generally very developed with

infrastructure and inhabited by a large

population that can’t be easily moved and face

potential dire consequences due to coastal

threats.”


What is Coastal Resilience?

Improve the ability of natural habitat and human communities to

“Recuperate" after damaging events such as hurricanes, coastal

storms, and flooding, rather than simply reacting to impacts.

Approaches

1) Assess Risk and

Vulnerability

2) Identify Solutions

3) Take Action

4) Measure Effectiveness


Efforts to analyze coastal flood and potential risk

A storm surge inundation model for coastal planning and impact studies. (Hubbert, G. D. and McInnes,K. L. 1999).

An integrated storm surge modeling system: CH3D-SSMS. Department of Civil and Coastal Engineering,University of Florida, Gainesville. (Sheng, Y. P., et. al. 2004)

Simulation of storm surge, wave, currents and inundation in the outer banks and Chesapeake Bayduring Hurricane Isabel in 2003. (Sheng, Y.P. et. al., 2010)

The Storm Surge and Sub-Grid Inundation Modeling in New York City during Hurricane Sandy (Harry V. Wang el.al., 2014)

Street-Scale Modeling of Storm Surge Inundation along the New Jersey Hudson River Waterfront, Stevens Institute of Technology, Hoboken, New Jersey. (Alan F. Blumberg et. al., 2015)

Modeling the Effectiveness of a Storm Surge Barrier System for the Houston Ship Channel during Hurricane Events. (Torres. J et. al. 2015)


North Atlantic Coast Comprehensive Study (NACCS):

Resilient Adaptation to Increasing Risk

What is the NACCS Study?

TIER 1 is a regional scale analysis (completed as part of this study)

TIER 2 Analysis conducted at a State or watershed scale

TIER 3 a local-scale analysis that incorporates benefit-cost evaluations of coastal storm risk management plans.

Key Findings, Outcomes & Opportunities

Increasing Flood Risk

Should adopt combinations of solutions

Identify acceptable

level of residual risk

Improve risk management Framework

Addressing coastal risk

Strategic and comprehensi

ve monitoring

Pre-disaster planning and

mitigation


NACCS Modelling EffortKey Points

Over 1,150 production storms were designed (synthetic storms) or selected (historical storms), simulated, analyzed, and incorporated into the Coastal Hazards database.

The development of synthetic tropical storms focused on: the discretization of the marginal distributions for each of the hurricane parameters; the development of the hurricane track paths; and development of the along-track variations of hurricane parameters.

Numerical models applied to the NACCS study WAM - Wave Prediction Model

STWAVE - Steady State Spectral Wave and ADCIRC - Advanced Circulation Model

Products from this work incorporated into the Coastal Hazards database for approximately 1,050 synthetic tropical events and 100 extra-tropical events computed at over 3 million computational points - 18,000 locations.

Exposure Assessment

Risk AssessmentRisk Areas

Identification

NAACS Concepts to Analyze Risk and Vulnerability


Identify Possible Solutions – Coastal Storm Risk

Management Strategies and Measures

Structural

Non-Structural

Natural & Nature-Based Features (NNBF)

Programmatic

Rocky

Beaches

Manmade Structures

Scraps

Vegetated Banks

Wetlands

Categorize based on function Categorize based on Shoreline type

Aggregated Measure Type

CategoryCoastal Storm Risk Management Function

Multi BenefitsResilience

Flooding Wave Attenuation

Erosion Adaptive Capacity

Acquisition (building removal) and

relocationNon-STR High High High High High

Deployable floodwalls

STR Medium None None None Low


FEMA’s Probabilistic Coastal Flood Hazard Analyses in

the Atlantic Ocean, Gulf of Mexico and Great Lakes Coasts

Phase 1:

Evaluate the existing FEMA procedures for delineating coastal flood hazard areas in three major coastal regions Atlantic, Gulf of Mexico, and Pacific Coast

Phase 2:

Develop recommended guidelines and procedures for mapping flood hazards on the Pacific coast

Phase 3:

Update coastal flood hazard mapping guidance for the Atlantic and Gulf of Mexico coasts

FEMA’s Numerical Modeling Framework

STEP 1: Storm Characterization

STEP 2: Storm Surge Modeling

STEP 3: Return Period Analysis

OUTPUT: 1% Annual Chance Still Water Level (SWL)

STEP 4: Overland Wave Analysis

OUTPUT: Flood Insurance Rate

Map


Storm Rate and Storm Characterization

“Quadrature JPM - OS (Joint-Probability Method – Optimum Sampling) schemes havebeen applied in recent FEMA’s probabilistic Storm surge studies”

P - Pressure deficit (representing hurricane

intensity),

RP - The radius of the exponential pressure profile

(representing hurricane size),

Vf - the forward velocity,

- the storm heading,

d - the landfall location (or, equivalently, the

minimum distance from the track to a reference point

along the coast)

“These parameters represent the main

hurricane characteristics affecting storm

surge; they are treated as random variables in

the JPM formulation.”


Established Tropical Storm and Hurricane (Gulf of Mexico)

Period: 1940 – 2008 (Historical) Period: 1940 – 2008 (Historical)


Coastal Flood Hazard Analyses in the Atlantic Ocean & Gulf of Mexico: Hydrodynamic & Wave Modeling

Still Water Level

FEMA Flood Hazard Map

Needs of Resilience – New York / New Jersey

Region


Breezy Point, New York: Hurricane

Sandy

Picture: The Philadelphia Inquirer,

Clem Murray/AP

Picture: Mike Groll /AP

Flooding in Pompton Plains, New Jersey

hit by wake of Hurricane Irene

Picture: http://meredithdf.tumblr.com/New York

Harbor/Hurricane Irene

The Plaza, Manhattan, NYC: Hurricane Sandy

Picture: EPA/Justin Lane

Picture: http://meredithdf.tumblr.com/

Picture: http://Wikipedia.org/

Flooding at Staten Island New

York /Hurricane Irene

Picture: USGS

According to a recent climate central survey report an estimated populationof around 236,000 and 423,000 respectively, in New Jersey and New Yorkregion are reportedly at risk due to rise in Sea levels and storm surge threats

Climate Central (http://sealevel.climatecentral.org/)

A walkway at the southern part of Battery

Park in Lower Manhattan/Hurricane Irene

Picture: www.dailymail.co.uk

NY/NJ Rebuild by Design Resiliency Projects


The BIG Team - The BIG U (East River Park) – Manhattan [New York City]

OMA – Resist, Delay, Store, Discharge - Hoboken, Weehawken, Jersey City [New Jersey]

The Interboro Team – Living With the Bay (Slow Streams) - Nassau County, Long Island [New York]

MIT CAU+ZUS+URBANISTEN– New Meadowlands - Little Ferry, Moonachie, Carlstadt, Teterboro [New

York]

SCAPE/Landscape Architecture– Living Breakwaters- Tottenville, Staten Island [New York]

Penn Design/OLIN –Lifelines, Hunts Point, South Bronx [New York City]


Typical Resiliency Framework

Integrated Flood Risk Assessment

Risk Areas Identification

Identify Combination of

Solutions

Flood Risk Management

Plan

Stakeholder process

Integrated design

Cost-Benefit Analysis

Implementation


Coastal Modeling for Resilience: Integrated

Approach Storm Surge

Rainfall


An example of Integrated Coastal Storm Surge /Storm Water

Management Modeling System

Example of Coastal Storm Surge Model (MIKE21)

Example of a Storm Water Model (MIKE URBAN)

Lower Manhattan, NY

HobokenNew Jersey

Brooklyn

Governors Island

BatteryPark


Example of an Integrated Coastal Storm Surge and Storm Water

Model (MIKE FLOOD)

Surge Barrier


Lesson Learned

The combination of rising sea-level, storm surge and storm water pose great flood risks to coastal

cities where population and assets are densely distributed.

An integrated methodology needs to be in place to gather and accurately interpret the comprehensive

information on potential flood risks.

The information obtained by this approach not only includes the flood risks on each subsystem but

also distinguishes between direct and indirect impacts.

Building resilience can be impetus for transforming the waterfront in ways that can make the city not

only more climate-resilient, but also more healthy, prosperous, and livable.

There are also many unknowns about the possible effects of many of the strategies discussed.

Therefore, in future, scientific modeling, empirical research, and pilot projects needs to be in

proposition.

International collaborations is required between climate research institutes for resource optimization to

overcome modelling limitations and improve regional and local models forecasts.

1 8 | Coastal Modeling for Resilience: Taking Steps Ahead

Dewberry’s Ongoing Coastal Resiliency Projects

Rebuild by Design – Hudson River Project (City of Hoboken, Jersey City and Town of Weehawken), New Jersey

Rebuild by Design - New Meadowlands Project, New Jersey

Red Hook Integrated Flood Protection Feasibility Study, New York

Lower Manhattan Coastal Resiliency, New York


Questions?

Thank You !

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