ASFPM 2016: Risk Identification Using Hazus

6/21/2016

Risk Identification using HazusCity of Boston, Suffolk County, MA

Dave Shortman, GISP, CFM

2

Agenda

Objective Project Location Hazus Overview Hazus Level 2 Risk Assessment Comparison and Reporting of Results Conclusions

Objective

3

4

Objective

The main objective of the study was to determine the potential economic loss associated with coastal flooding

Also to compare results from Hazus 2.1 to 3.1

Project Location

5

6

Project Location - Suffolk County, MA

Hazus Overview

Hazus

FEMA’s HAZards United States (HAZUS) tool is designed to produce loss estimates for use by federal, state, regional and local governments and private enterprises in planning for risk mitigation, emergency preparedness, response and recovery

HAZUS includes capabilities to analyze earthquakes, floods and hurricane winds

Hazus was recently updated with census 2010 data

9

Levels of AnalysisCommunity-Specific Damage Functions

Link HAZUS with Hydraulic Model

Distribution of Terrain

0%

5%10%

15%

20%

25%30%

35%

40%45%

Perc

enta

ge o

f Are

a

Dam

age

Flood Depth

Level 1

Use Default Databases

Level 1 DefaultDatabases

Level 2 UserModified

Data

Level 3 ExpertSupplied

Data

Modify Building Inventory

Aerial Photo

Number of Buildings by Specific Occupancy

0

20

40

60

80

100

120

RES1 RES2 RES3 RES4 RES5 RES6

Bui

ldin

g C

ount

10

Flood Model Methodology

Define Hazard: Flood Surface Land Surface

Define and Overlay Inventory

Determine Damage

Estimate Losses

Level 1 Analysis – Floodplain Boundary

Level 1 Analysis – Buildings with Substantial Damage

Level 1 Analysis – Total Losses

HAZUS Level 2 Risk Assessment

14

Boston Harbor HAZUS Study

Level 2 analysis using historic flood hazard information and census data – Effective Flooding (1990)

Level 2 analysis using detailed engineering data along with census data – Preliminary (2013) and Revised Preliminary (2015, new effective)

“Modified” Level 2

Defining the Hazards

Topographic data from FEMA’s Charles River HUC 8 LiDAR FY2010

Flood surface generated from Effective Data (1990 FIS, study

performed in 1987) Preliminary Data (November 15,

2013) Revised Preliminary Data (July 9,

2015) Using CHAMP/WHAFIS results

along with updated elevation data we developed depth grids that are compatible with the HAZUS model

Census data from Hazus 2.1 & 3.1








Census block data from Hazus 2.1 & 3.1

Waterfront Development AreasSouth Boston Waterfront (Effective SFHA overlay)

Coastal Updates

CDM

Can we incorporate the idea of showing BFE increases:0-1 ft BFE increase1-3ft BFE increase3-4ft BFE increaseetcMaybe represtnt as line or dot overlay?

Waterfront Development AreasSouth Boston Waterfront (Preliminary SFHA overlay)

Coastal Updates

Waterfront Development AreasEast Boston Shorefront (Effective SFHA overlay)

Coastal Updates

CDM


Waterfront Development AreasEast Boston Shorefront (Preliminary SFHA overlay)

Coastal Updates

CDM










East Boston

South Boston

Fenway

Charlestown

Downtown

South End

Back Bay

South Boston Waterfront

Beacon Hill

North End

West End

Chinatown

Bay Village

Leather District

REVERE

MEDFORD

CAMBRIDGE

SOMERVILLE

WINTHROP

BOSTON

EVERETT

CHELSEA

Fort

Poin

t Cha

nnel

BostonHarbor

Legendwhdepth2015Value

High : 45.4059

Low : -24.3278

Town Boundary

NeighborhoodsN

0 1 20.5Miles

Charles River

Mystic River

Chel

sea R

iver

Boston Harbor HazusWoods Hole Group

Residential Total Loss

Shortman, David

Add depth grid map here









24

Dasymetric Data

Hazus 2.1 Hazus 3.1

Results

25

East Boston

South Boston

Fenway

Charlestown

Downtown

South End

Back Bay


Beacon Hill

North End

West End

Chinatown

Bay Village

Leather District

REVERE

MEDFORD

CAMBRIDGE

SOMERVILLE

WINTHROP

BOSTON

EVERETT

CHELSEA

Fort

Poin

t Cha

nnel

BostonHarbor

LegendTotalLoss

0

1 - 1000

1001 - 2000

2001 - 3000

3001 - 4000

4001 - 5000

5001 - 8000

8001 - 10000

10001 - 17500

Town Boundary

Neighborhoods

N

0 1 20.5Miles

Charles River

Mystic River

Chels

ea R

iver

Boston Harbor HazusEffective

Total Loss

Total Losses – EffectiveHazus 2.1 Hazus 3.1

East Boston

South Boston

Fenway

Charlestown

Downtown

South End

Back Bay


Beacon Hill

North End

West End

Chinatown

Bay Village

Leather District

REVERE

MEDFORD

CAMBRIDGE

SOMERVILLE

WINTHROP

BOSTON

EVERETT

CHELSEA

Fort

Poin

t Cha

nnel

BostonHarbor

LegendTotalLoss

0

1 - 1000

1001 - 2000

2001 - 3000

3001 - 4000

4001 - 5000

5001 - 8000

8001 - 10000

Over 10000

Town Boundary

Neighborhoods

N

0 1 20.5Miles

Charles River

Mystic River

Chels

ea R

iver

Boston Harbor HazusRevised Preliminary

Total Loss

Total Losses – Revised PreliminaryHazus 2.1 Hazus 3.1

Summary

Hazus 2.1 Results: Overall Exposure: $32,381.1M Damages:

Effective Total: $305M Building Loss: $141.5M Contents Loss: $158.5M Other Loss*: $50.1M

Revised Preliminary Total: $973.2M

Building Loss: $345.7M Contents Loss: $592.7M Other Loss*: $34.8M

*Other Loss Includes Inventory, Relocation, Income, Rental Income, and Wage Losses

Hazus 3.1 Results Overall Exposure: $94,466.4M* Damages:

Effective Total:$268.8M

Building Loss:$119.9M

Contents Loss:$145.0M

Other Loss*:$3.9M

Revised Preliminary Total:

$1,274.6M Building Loss: $434.1M Content Loss: $800.9M Other Loss: $39.7M

Structure Density – Boston NorthStructures Added to Preliminary SFHA

Coastal Updates

CDM

I'm sorry to go back and forth, but after looking through the other figures and some of the labels (i.e. we are terming coastal high hazard areas as different from special flood hazard areas) i now think we shoudl consistently call this Special Flood Hazard Areas -So - change title of slidde and color scale to "Structures added to prelim special flood hazard areas" and change green polygon label to Preliminary Special Flood Hazard Areas

Mark Zito

The green color is too close to the gray, try using a light blue or a brighter green. Blue is more representative of flooding. Use a transparency as well.

Coastal Updates

Structure DensityPopulation Density for StructuresWithin the Preliminary SFHA

Population Density – Boston NorthPopulation Density for StructuresWithin the Preliminary SFHA

Changes Since Last FIRM

Community Change Area mi2

Area Increase mi2

Area Decrease mi2

Area Net mi2

Boston CHHA 5.3 2.0 0.0 2.0Boston SFHA 12.3 2.8 0.2 2.6Boston NonSFHA 2.0 1.4 0.0 1.4Chelsea CHHA 0.1 0.1 0.0 0.1Chelsea SFHA 1.2 0.7 0.0 0.7Chelsea NonSFHA 0.1 0.1 0.0 0.1Revere CHHA 0.7 0.1 0.0 0.1Revere SFHA 3.4 0.4 0.0 0.4Revere NonSFHA 0.3 0.1 0.1 0.0Winthrop CHHA 1.0 0.5 0.0 0.5Winthrop SFHA 1.9 0.2 0.0 0.2Winthrop NonSFHA 0.0 0.0 0.0 0.0Suffolk County CHHA 7.1 2.7 0.0 4.4Suffolk County SFHA 18.6 4.1 0.2 3.9Suffolk County NonSFHA 2.4 1.6 0.1 0.8

Change DefinitionsCHHA – coastal high hazard area (Velocity zone increase/decreaseSFHA – special flood hazard area increase/decrease (Zone A, AE, AO, AH)NonSFHA – 0.2% Annual Chance Flood increase/decrease

CDM

I really like this figure! - is the labeling "CHHA" standard for CSLF flood risk datasets? I ask because that's not a term I see very often and our audience likely won't know that abbreviation means- I believe it means Coastal High Hazard Area, which is great to highlight, but I think there may be misunderstanding between SFHA and CHHA areas - technicaclly SFHA includes both coastal (CHHA) and non-coastal flood hazard areas (so AE and VE). How about we change CHHA to say "VE Zones" and change SFHA to say (Zone A, AE, AO, and AH) - if I have those categories correct, that is?Also, just checking that NonSFHA includes both shaded (0.2%) and unshaded zone x?

Troy Thielen

considering Laura/Mark comments, recommend changing CHHA to "V-Zones".The green change areas in the lower-left non-coastal areas needs to be removed.

Mark Zito

CHHA does stand for Coastal High Hazard Area. I am not sure if it is a widely used term, but it is the abbreviation used in the G&S. The SFHA summaries are inclusive of the CHHA changes.

Comparison to HAZUS-MH Values in Draft Natural Hazard Mitigation Plan Analysis done by Metropolitan Area Planning Commission Earthquake Damages

5.0 magnitude with an epicenter in downtown Boston - $3,450.0M 6.0 magnitude with an epicenter on Cape Ann - $431.7M 6.5 magnitude with an epicenter in central New Hampshire - $457.1M

Wind Damages 1938 Hurricane - $372.2M Hurricane Carol (1954) - $819.6M Hurricane Irene (2011) - $8.6M

Riverine and Stream Flooding (100 year event) Charles River Watershed - $16.6M Mother Brook Watershed - $105.6M Muddy River Watershed - $81.1M Mystic River Watershed - $9.0M Combined - $212.3M

Conclusions

Updated SFHA and topographic data provide more accurate results

Hazus 3.1 gives an up to date assessment of exposure and damages Boston coastal housing and commercial stock has gained significant

value since 2000 census Coastal development has increased Barring a major event the growth in Boston will continue Hazus with 2020 census? Flood Risk Assesment Database cannot handle these values (Long

data type ~ 2.1 billion)

Questions?

Environment

ASFPM 2016: Risk Identification Using Hazus