Using HAZUS for the Flood Risk Assessment Dataset within FEMA Risk MAP Studies

Dr. Shane Parson, PE, CFM, URS (RAMPP Team)

2011 ASFPM Annual National ConferenceLouisville, KY

2

Agenda Overview

Average Annualized Loss (AAL Study)

Risk MAP – Flood Risk Assessment Dataset• Process• AAL Data• Refined HAZUS Data• Composite Data• Flood Risk Products Use: Database, Report, Map

3

Flood Risk Assessment DataPurpose and Intended Uses Identify Areas and Communicate Relative Flood Risk:

• Flood-prone areas• Vulnerable people and property

Provide Flood Risk $:• Potential damage severity for different flood frequencies • Identify locations with possible cost effective mitigation options

Improve Estimates for Flood Risk $:• Losses from Average Annualized Loss (AAL) Study • Refined losses from new flood study depth grids

4

AAL Study 2010 HAZUS-MH Flood Average Annualized Loss

Estimation (AAL) was performed for continental U.S. using MR4

Inputs:• County-wide study regions• 30 meter DEM• Default Census data

Final Output included:• Total exposure• Average Annualized Loss• Annualized Loss Ratio

5

AAL Usability for Risk MAP Initial study focused on providing state and

watershed based results

As Risk MAP looks to use more detailed results (census block level), an AAL Usability Analysis was conducted to better understand its limitations and refine AAL results as appropriate.

6

Flood Risk AssessmentInputs, Outputs, and Delivery Inputs:

• HAZUS AAL Data Source: FEMA• Draft flood depth grids Source: Flood Depth Grid Analysis• Enhanced data Source: Discovery / Local, State, Fed.

GIS

Outputs:• Flood Risk Assessment dataset

– HAZUS AAL Data– Refined HAZUS Data – Composite Data (includes data used for Flood Risk Report and Map)

Delivery:• Drafts presented at Resilience Meeting• Final delivered after Flood Risk review and discussions• Incorporated within Flood Risk DB, Report, and Map

7

Development of the Flood Risk Assessment Dataset in Risk MAP

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

Enhanced Flood Risk Assessment Analyses Enhancements could

include:• Risk Assessments at site-

specific locations• Incorporation of locally-

provided inventory data (first-floor elevations and/or parcel data)

• Additional sources of flood depth grids

• Supplemental HAZUS analyses or other types of analyses

27

Refined HAZUS Data – Content Scalability Flood Risk Assessment

HAZUS analysis for reaches with new or updated studies where depth grids can be generated

Should include 10%, 4%, 2%, 1%, and 0.2% annual chance events and Annualized Loss

HAZUS GBS Losses (dollar losses, percent damage, business disruption)

Enhancements Additional events Additional HAZUS loss calculations (infrastructure, critical

facilities, user-defined facilities) Use of local data to updated/supplement HAZUS data Non-HAZUS analysis methods (needs to be able to produce the

required output to populate the associated tables in the flood risk database)

28

Composite Data – Content Scalability Flood Risk Assessment

HAZUS Combination of AAL and Refined HAZUS Data Should include 10%, 2%, 1%, and 0.2% annual chance events

and Annualized Loss (may include more events) HAZUS GBS Losses (dollar losses, percent damage, business

disruption)

Enhancements Only included if results to be show in Flood Risk Report or Flood

Risk Map

29

Flood Risk Assessment Delivered

30

Flood Risk Map Elements

31

Flood Risk Report Elements

32