14-April Univ of Delaware Philadelphia Engineer District 1 Delmarva Hurricane Evacuation Study (HES) Jason F. Miller, P.E. U.S. Army Corps of Engineers,

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14-AprilUniv of Delaware

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Delmarva Hurricane Evacuation Study (HES)

Jason F. Miller, P.E.

U.S. Army Corps of Engineers,

Philadelphia District

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The Basics

• What is a Hurricane?A hurricane is a type of tropical cyclone, which is a generic term for a low pressure system that generally forms in the tropics. The cyclone is accompanied by thunderstorms and, in the Northern Hemisphere, counterclockwise circulation of winds near the earth's surface.

• Hurricanes are categorized according to the strength of their winds using the Saffir-Simpson Hurricane Scale. A Category 1 storm has the lowest wind speeds, while a Category 5 hurricane has the strongest. These are relative terms, because lower category storms can sometimes inflict greater damage than higher category storms, depending on where they strike and the particular hazards they bring. In fact, tropical storms can also produce significant damage and loss of life, mainly due to flooding.

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The Basics (cont.)

• What is Storm Surge?Storm surge is the difference between the observed water level and the normal astronomical tide; generally brought about by a very large meteorological disturbance (hurricane).

• Wind is the primary cause of storm surge by inducing currents in the direction of the wind.

• Surface current in turn produces subsurface currents. When these currents meet the sloping continental shelf, the water level rises (surge).

• Slower moving hurricanes tend to create deeper subsurface currents, and therefore may create higher surges than fast moving systems.

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tHURRICANE EVACUATION

STUDY

To provide information to emergency management officials that will be useful in hurricane evacuation decision-making and implementation.

Program Objective

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t • HAZARDS ANALYSIS

• VULNERABILITY ANALYSIS

• BEHAVIORAL SURVEYS

• SHELTER STUDIES

• TRANSPORTATION ANALYSIS

HES Components

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• QUANTIFY SURGE HEIGHTS FOR INTENSITIES AND TRACKS OF HURRICANES CONSIDERED TO HAVE A REASONABLE METEOROLOGICAL PROBABILITY OF OCCURRENCE WITH STUDY AREA

TIDAL FLOODINGTIDAL FLOODING

SlightlySlightlyDatedDatedPhotoPhoto

HAZARDS

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ASSESS POTENTIAL EFFECT OF INLAND (RAINFALL) FLOODING HAZARDS ON EVACUATIONS

RIVERINE FLOODINGRIVERINE FLOODING

HAZARDS

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tSea, Lake and Overland Surges from

Hurricanes

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SLOSH Data

• MEOW

Maximum Envelope Of Water: Based on hypothetical storm track and intensity

• MOM

Maximum Of Maximums: Composite of MEOWs for each category storm

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tSLOSH MODEL CAT 3 MAXIMUM SURGE SLOSH MODEL CAT 3 MAXIMUM SURGE

ELEVATIONSELEVATIONS

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DIGITAL ELEVATION MODEL (DEM)DIGITAL ELEVATION MODEL (DEM)

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Digital Elevation ModelDigital Elevation Model(ground elevations)(ground elevations)

Resultant Inundation AreaResultant Inundation Area

Surge Height GridSurge Height Grid

Ground elevationssubtracted fromsurge heights to determine areasSubject to flooding

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• IDENTIFY AREAS, POPULATIONS IDENTIFY AREAS, POPULATIONS AND FACILITIES THAT ARE AND FACILITIES THAT ARE VULNERABLE TO HURRICANE VULNERABLE TO HURRICANE SURGE AND WINDSURGE AND WIND

VULNERABILITY ANALYSISVULNERABILITY ANALYSIS

11STST STEP: INUNDATION MAPPING STEP: INUNDATION MAPPING22NDND STEP: ASSEMBLE CENSUS AND RELATED DATA STEP: ASSEMBLE CENSUS AND RELATED DATA

AND ASSEMBLE HIGHWAY DATAAND ASSEMBLE HIGHWAY DATA

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Vulnerability Zones

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TRAFFIC ANALYSIS ZONESTRAFFIC ANALYSIS ZONES- Used to support traffic modelingUsed to support traffic modeling

EVACUATION ZONESEVACUATION ZONES - Used operationally by emergency - Used operationally by emergency

management officialsmanagement officials

VULNERABILITYVULNERABILITYANALYSISANALYSIS

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Assumptions regarding public responseAssumptions regarding public response

- Percentage of the population that will evacuate under Percentage of the population that will evacuate under a range of hurricane scenarios and/or in response to a range of hurricane scenarios and/or in response to evacuation advisoriesevacuation advisories

- Timing of public responseTiming of public response

- Number of vehicles that evacuees will useNumber of vehicles that evacuees will use

- Probable Destinations (shelter, with local friends, local Probable Destinations (shelter, with local friends, local hotel/motel, out-of-county, out-of-state)hotel/motel, out-of-county, out-of-state)

- Responses of touristsResponses of tourists

Behavioral Analysis – Behavioral Analysis –

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•I lived here for 35 years and…I lived here for 35 years and…•I’ve really never thought about it.I’ve really never thought about it.•What about my pets?What about my pets?•A Category 1 isn’t too bad.A Category 1 isn’t too bad.•I don’t live on the beach.I don’t live on the beach.•I don’t have reliable transportationI don’t have reliable transportation

BEHAVIORAL SURVEYSBEHAVIORAL SURVEYS

Documents

14-April Univ of Delaware Philadelphia Engineer District 1 Delmarva Hurricane Evacuation Study (HES) Jason F. Miller, P.E. U.S. Army Corps of Engineers,