Step 4: Estimate Losses

Overview
The fourth step in the risk assessment process involves running the HAZUS-MH 
loss estimation models. For this step, you will run HAZUS-MH loss estimation 
models and scenarios, and evaluate your hazard events and inventory results for 
your study region. In addition, you will be introduced to the Risk Assessment 
Tool (RAT), a companion software tool to HAZUS-MH that will help you to expedite 
the preparation of your risk assessment outputs, and to the Flood Wizard, a 
companion software tool to HAZUS-MH that will quickly assess inventory exposure 
and loss for a study region.  Figure 4-1 provides the tasks and outputs for this 
step.

Figure 4-1. Step 4 tasks and outputs
Step 4:  Estimate Losses
TASKS:
4.1 Integrate Hazard Profile Data for HAZUS-MH Level 2
4.2 Run HAZUS-MH Scenarios
4.3 Run the Risk Assessment Tool
4.4 Calculate Exposure for Hazards Not Included in HAZUS-MH
4.5 Evaluate the Results of Your Risk Assessment
OUTPUTS:
--HAZUS-MH Loss Estimate Tables, Maps, and Summary Reports(Worksheets 4-1 and 4-
2)
--Flood Wizard and Risk Assessment Tool Outputs (Worksheet 4-2) 


HAZUS-MH includes loss estimation models for earthquake, flood, and hurricane 
hazards. Task 4.1 involves setting up your scenarios to obtain loss estimates. 
Task 4.2 explains how to run the HAZUS-MH models. Task 4.3 involves preparing 
and documenting a risk assessment using the RAT, a companion software tool to 
HAZUS-MH. Task 4.4 addresses how HAZUS-MH can support the identification of 
assets exposed to hazards other than earthquakes, floods, and hurricanes. Task 
4.5 involves reviewing and evaluating the estimates generated during Tasks 4.1, 
4.2, 4.3, and 4.4 to assess their completeness, compare risks, and evaluate 
acceptability. 

Sidebar: Wizard: The Risk Assessment Tool
FEMA has developed a companion software tool to HAZUS-MH called the HAZUS-MH 
Risk Assessment Tool (RAT) to help you produce your risk assessment outputs for 
earthquakes, floods, and hurricanes. This tool was developed as a third-party 
model to support HAZUS-MH and is used to display the outputs from the HAZUS-MH 
risk assessment in an easy-to-use format.  

Sidebar: Definition: HAZUS-MH Loss Estimate Terms
Loss  Structural loss, content loss, and function loss
Functional downtime  The average time (in days) during which a function 
(business or service) is unavailable to provide its services because of a hazard 
event
Displacement time  The average time (in days) that a buildings occupants must 
operate from a temporary location because of building damage resulting from a 
hazard event
Function loss  Functional downtime costs + displacement time costs
Casualties  Impacts on humans (ranging from low impact to severe injury and 
death)
Return period loss  The average loss over a certain period of time for all 
hazard events

 
Deterministic and Probabilistic Scenarios in HAZUS-MH
To obtain loss estimation results, HAZUS-MH runs deterministic and probabilistic 
scenarios. For the purpose of this How-To Guide, probabilistic scenarios are 
identified as the best option for the following reasons:
--The estimated losses are the average expected value of loss in any one year.  
--An average of expected value of losses can help decision-makers to plan cost-
effective budgets to address high priority natural hazard concerns.
--The average annualized losses can help to identify cost-effective mitigation 
measures. 
--Cost-effective mitigation measures can produce savings (avoided losses) and 
help to address budgetary needs and constraints.

Sidebar: Note: Exposure
Although it is not used in this context in HAZUS-MH, the term exposure is 
insurance parlance for the dollar value of the risk portfolio and is thus 
applicable to discussions of loss estimation as well as general inventory 
identification.

Probabilistic analyses can be used to develop estimates of average yearly losses 
(annualized losses) as well as the expected distribution of losses (return 
period losses). These estimates reflect the full spectrum of potential events 
that can occur in a particular region. The probabilistic approach allows the 
user to generate estimates of damage and loss based on probabilistic hazards for 
five (flood), seven (hurricane), or eight (earthquake) return periods.  

Sidebar: Definition: HAZUS-MH Annualized Losses
HAZUS-MH allows you to estimate annualized losses. Annualized loss is the 
estimated long-term value of losses to the general building stock averaged on an 
annual basis for a specific hazard type. Annualized loss considers all future 
losses for a specific hazard type resulting from possible hazard events with 
different magnitudes and return periods averaged on a per year basis. Like 
other loss estimates, annualized loss is an estimate based on available data and 
models. Therefore, the actual loss in any given year can be substantially higher 
or lower than the estimated annualized loss.

Refer to Chapter 15 of the Earthquake Technical Manual for more details.

Deterministic analysis relies on the laws of physics or on correlations 
developed through experience or testing to predict the outcome of a particular 
hazard scenario. In the deterministic approach, one or more possible scenarios 
can be developed that represent the worst possible credible events. In this 
approach, the frequency of possible occurrence needs to be evaluated.

Probabilistic analysis evaluates the statistical likelihood that a specific 
event will occur and what losses and consequences will result. The probabilistic 
approach may use both statistics and historical information. This How-To Guide 
focuses on probabilistic analysis. The HAZUS-MH User Manuals contain 
instructions concerning both scenarios.

Using HAZUS-MH provided data or local data already incorporated into the 
software, proceed to run HAZUS-MH. Preliminary results will take the form of 
standardized hazard outputs. These outputs estimate damages and losses, 
including direct losses, induced losses, social losses, and business 
interruption.

Sidebar: Note: Points To Keep In Mind When Estimating Losses
HAZUS-MH estimates aggregate impacts on buildings and other structures and on 
general areas. It is an estimation tool and does not identify which specific 
buildings might be impacted. The loss estimation results are estimates of 
overall impacts that are intended to guide overall mitigation efforts. However, 
due to the limited history of observations for some hazards (e.g., hurricanes), 
limited knowledge of actual building characteristics, modeling simplifications, 
and other factors, the user may encounter some variation in the results produced 
by a probabilistic analysis.

Developing the loss estimates in HAZUS-MH will require five activities: 
--Integrate hazard profile data for HAZUS-MH Level 2
--Run HAZUS-MH scenarios
--Run the RAT
--Calculate exposure for hazards not included in HAZUS-MH
--Evaluate the results of the risk assessment 
 
These activities are detailed below, for the three major hazards addressed by 
HAZUS-MH.


Integrate Hazard Profile Data for HAZUS-MH Level 2 (Task 4.1)
Data integration is required if you have collected local data as part of Task 
2.3 to supplement the HAZUS-MH provided data. Local hazard data integration is 
discussed below for the earthquake, flood, and hurricane hazards.


Earthquakes 
There are two techniques in the earthquake module to update the hazard 
assumptions and data provided with HAZUS-MH. The first method involves changing 
the soil type, landslide, liquefaction, and water depth values for the study 
region as a whole. The second method involves importing a GIS layer into HAZUS-
MH and using the values found in the attribute table of that layer to update the 
soil type, liquefaction, landslide, and water depth values.

To update the assumptions for the study region, follow the directions below.
1. To access the Scenario Wizard, select Scenario under the hazard menu. The 
Earthquake Hazard Scenario Selection menu will become available as shown in 
Figure 4-2).
2. To begin defining the hazard maps, select Define hazard maps under 
Scenario event. Then click Next. The Define Hazard Maps Option menu will now 
be available, as shown in Figure 4-3.
3. To assign a value to the entire study region, open the drop-down box to the 
right of Class or Value, and select or type the appropriate value. Refer to 
Appendix B in the HAZUS-MH Earthquake Technical Manual for a more detailed 
description of the hazard map values. 

To integrate the earthquake hazard data as map layers collected in Step 2, 
follow the directions below.
1. To begin integrating your local hazard data, select Data Maps under the 
Hazard menu. The Data Maps Dialog box will become available.
2. To locate your local data, select Add map to list. Then browse to the 
location of your soil map collected in Step 2. This map should be in the 
geodatabase file format. Repeat this process for the liquefaction, landslide, 
and water depth maps at this time.
3. To begin using your data in a scenario, select Scenario under the Hazard 
menu. The Earthquake Hazard Scenario Selection menu will become available as 
shown in Figure 4-2.
4. To define your local data, select Define hazard maps under Scenario 
event. Then click Next. The Define Hazard Maps Option menu will now be 
available, as shown in Figure 4-3.


Figure 4-2: Earthquake hazard scenario selection menu. Graphic showing computer 
screenshot of the earthquake hazard scenario selection menu.


Figure 4-3: Define hazard maps option menu. Graphic showing computer screenshot 
of the define hazard maps option menu.


Floods (Coastal)
You will use the Flood Information Tool (FIT) provided with the HAZUS-MH suite 
of programs, to integrate the local flood hazard maps you collected in Step 2. 
The FIT allows you to integrate local flood hazard data into HAZUS-MH. The local 
flood hazard data may include topographic data, a digital elevation model (DEM), 
flood elevations, floodplain boundaries, Q3 data, FIRM data, and DFIRM data. 
Before running the FIT, you need to have the following datasets in a common 
projection:
 a.  A DEM in grid format
 b.  Flood elevations in polyline and polygon formats
 c.  Floodplain boundaries in polygon formats

Sidebar: Reference: Additional instructions for using the FIT are available in 
Section 3.3 of the Flood User Manual and the FIT User Manual.  

The FIT is run from HAZUS-MH or ArcGIS; it is not a stand-alone program. The FIT 
is an ArcGIS extension that can not be installed from the HAZUS-MH wizard. FIT 
must be installed using the Flood Information Tool installer.  Start the HAZUS-
MH program and load the flood toolbar to begin using the FIT. To load the 
toolbar (shown in Figure 4-4), right click on the menu and select Flood 
Information Tool. The FIT consists of modules for riverine and coastal 
analyses.


Figure 4-4: FIT startup menu. Graphic showing computer screenshot of the flood 
toolbar and the FIT startup menu.


To run the FIT for a coastal analysis, follow the instructions below.
1. To setup and validate your project, identify your input map layers (datasets 
a [DEM], b [flood elevation], and c  [floodplain boundary]); collect 
project information; and ensure that the input data share the same projection, 
reference datum point, and units.  Information needs to be completed under four 
tabs, as shown in Figure 4-5. 
--The General tab allows you to select the flood hazard and define the working 
directory, basin name, and reach name.
--The Ground Surface tab allows you to specify the DEM layer (data set a).
--The Flood Surface tab allows you to identify the flood elevation map layer 
(data set b).
--The Floodplain Boundary tab allows you to select the floodplain boundary 
layer (data set c) and collect description information.


Figure 4-5: Project setup screen. Graphic showing computer screenshot of the 
project setup screen, which includes four tabs for entering information.


2. To begin to use the coastal flood depth grid wizard, define the flood area 
and characteristics to be analyzed within your study region. You will also 
develop flood depth grids around coastal areas. To run the FIT for a coastal 
flood, an onscreen menu will guide you through the following process:
a. Build the elevation grid
b. Draw the shoreline at mean sea level
c. Define the shoreline segments
d. Define the shoreline characteristics
e. Compute the flood depth grids

At this point, all your flood hazard profile data should be compatible and 
loaded into HAZUS-MH. 


Floods (Riverine)
HAZUS-MH will support the evaluation of the flood hazard using two methods, a 
detailed loss estimate described below and an exposure and loss estimation using 
the Flood Wizard discussed in Step 4.2. The detailed loss estimate requires a 
significant amount of processing time and may not be feasible for larger study 
regions.

The FIT allows you to integrate local flood hazard data into HAZUS-MH.  The 
local flood hazard data may include topographic data, a DEM, flood elevations, 
floodplain boundaries, Q3 data, FIRM data, and DFIRM data. Before running the 
FIT, you need to have the following datasets in a common projection:
a.  A DEM in grid format
b.  Flood elevations in polyline and polygon formats
c.  Floodplain boundaries in polygon formats

The FIT is run from HAZUS-MH or ArcGIS because the tool is not a stand-alone 
program. Start the HAZUS-MH program and load the flood toolbar to begin using 
the FIT. Select the FIT for riverine analysis (see Figure 4-4).

To run the FIT for a riverine analysis, follow the instructions below:
1. Setup and validate project. This activity involves identifying your input map 
layers (datasets a [DEM], b [flood elevation], and c [floodplain boundary]); 
collecting project information; and ensuring that the input data share the same 
projection, reference datum point, and units. Information needs to be completed 
under four tabs as shown in Figure 4-5. 
--The General tab allows you to select the flood hazard and define the working 
directory, basin name, and reach name.  
--The Ground Surface tab allows you to specify the DEM (data set a), and 
select the source, elevation units, and vertical datum.  Also, it displays the 
projection and cell units.
--The Flood Surface tab allows you to identify the flood elevation map layer 
(data set b), display metadata, and collect description information.  
--The Floodplain Boundary tab allows you to identify the floodplain boundary 
layer (data set c), including the elevation units and vertical datum, and to 
specify descriptive information.

2. Use the riverine flood depth grid wizard. This activity involves defining the 
flood area to be analyzed within your study region. You will also develop flood 
depth grids around rivers and backwater areas and merge these grids. To develop 
and merge your flood depth grids, an onscreen menu will guide you through the 
following process:
a. Select the upstream and downstream limits of your analysis areas
b. Define the width of your analysis areas
c. Adjust the buffer zone to balance inclusion of flooded areas and processing 
time
d. Define flood elevation attribute fields
e. Draw polygons around backwater areas
f. Assign elevations to backwater areas
g. Merge all flood depth grids

At this point, your local flood hazard profile data should be compatible and 
integrated into HAZUS-MH.


Hurricanes
The HAZUS-MH module assigns values (general parameters) for surface roughness 
and vegetation from national land use maps based on your geographic location. 
The Edit function of the hurricane model can be used when you have collected 
surface roughness and vegetation data. In this case, select Analysis from the 
HAZUS-MH main menu and then select Parameters. Select Terrain or Trees to 
change the values assigned to each Census block or tract.

If you want to update the assigned values, follow the directions below:  
1. To begin updating the terrain map, select Analysis from the HAZUS-MH main 
menu and then select Parameters. These menu items can be seen in Figure 4-6. 
Select Terrain to change the surface roughness values. The table in Figure 4-7 
should now be available to edit.


Figure 4-6: Editing the hazard maps. Graphic showing computer screenshot of the 
HAZUS-MH main menu, on which the "Analysis" dropdown list is shown and the 
"Parameters" and "Trees" selections have been highlighted.


Figure 4-7: Terrain table. Graphic showing computer screenshot of the terrain 
table, with a Surface Roughness Length value selected.


2. To edit a value in the terrain table, double click in the box you want to 
change and edit the number directly. You may also want to map the surface 
roughness of your study region. To map the values, click on the column title to 
highlight the entire column and select Map below. A GIS layer will show up on 
your study region.

3. To save changes to the terrain table, click OK.  A box will pop up asking 
if you want to save changes. Click Yes.  

4. To begin updating the trees map, select Analysis from the HAZUS-MH main 
menu and then select Parameters. These menu items can be seen in Figure 4-6. 
Select Trees to change the tree parameters. The table in Figure 4-8 should now 
be available to edit.


Figure 4-8: Tree parameter table. Graphic showing computer screenshot of the 
tree parameter table, with a Stems per Acre value selected.


5. To edit a specific parameter in the tree parameters table, double click in 
the box you want to change and edit the number directly. You may also want to 
map the different parameters in your study region. To map the values, click on 
the column title to highlight the entire column and select Map below. A GIS 
layer will show up on your study region.

6. To save changes to the tree parameter table, click OK. A box will pop up 
asking if you want to save changes. Click Yes. 

 Congratulations! You have now integrated in HAZUS-MH the information needed to 
run your loss estimation analyses.  


Run HAZUS-MH Scenarios (Task 4.2)
HAZUS-MH scenarios can be run for the earthquake, flood, and hurricane hazards. 
The steps to run these scenarios are discussed below. Worksheet 4-1 will help 
you document the results.

Run an Earthquake Scenario
To run a probabilistic earthquake scenario, follow the instructions below:
1. To begin setting up the scenario, select Scenario under the Hazard menu and 
then select Next. The Earthquake Hazard Scenario Selection menu will appear 
with four scenario event options: Define a new scenario, Use a pre-defined 
scenario, Delete an existing scenario, and Define hazard maps. Select 
Define a new scenario. The Seismic Hazard Type Selection menu shown in Figure 
4-9 will now appear.


Figure 4-9: Seismic hazard type selection menu. Graphic showing computer 
screenshot of the seismic hazard type selection menu.


2. To run a probabilistic analysis, select Probabilistic hazard under Seismic 
hazard type and click on Next. The Probabilistic Hazard Selection menu shown 
in Figure 4-10 will now appear. Select the return period and the moment 
magnitude of interest. This value could be estimated based on your historical 
research conducted in Step 2. For your risk assessment, you will want to run a 
HAZUS-MH analysis for all the return periods available as well as run the annual 
loss option. Select Next. The Hazard Scenario Event Name menu shown in Figure 
4-11 should now appear.


Figure 4-10: Probabilistic hazard selection menu. Graphic showing computer 
screenshot of the probabilistic hazard selection menu.


Figure 4-11: Hazard scenario event name menu. Graphic showing computer 
screenshot of the hazard scenario event name menu, on which the blank for 
entering an event name is shown.


3. To identify your scenario, enter a name for the scenario event (40 characters 
maximum) in the space provided. Click on Next to end the scenario wizard. 

4. To run your analysis, select Analysis on the main menu, and then select 
Run. The menu shown in Figure 4-12 should now be displayed, click on the plus 
and minus signs to expand and collapse the lists of available options. You can 
now run the analysis. The analysis options include general buildings, essential 
facilities, military installations, advanced engineering building mode, user-
defined structures, transportation systems, utility systems, induced physical 
damage, direct social losses, indirect economic impact, and contour maps. Select 
the categories of analysis you wish to perform, and click on OK. The 
earthquake model can perform all of the analysis options shown; the more you 
select, the longer the processing time. 


Figure 4-12: Analysis options menu. Graphic showing computer screenshot of the 
analysis options menu, on which available options are listed under the heading 
of Inventory View.



Run a Flood Scenario Using HAZUS-MH

Sidebar: HAZUS-MH software: The term "study case" in the flood module is similar 
to the term "scenario" in the earthquake and hurricane module.

To run a probabilistic flood scenario for a riverine or coastal flood, follow 
the directions below.
1. To begin running a flood scenario, select Study Case on the Hazard menu, 
and then select New. The study case defines the specific stream reaches or 
lengths of coastline and the hydrologic and hydraulic characteristics that you 
wish to include in one analysis run. A study case could include all the stream 
reaches in your study region, but because the analysis requires significant 
computer processing, you may wish to divide your study region into several 
smaller study cases. When the Run Hydrology option on the Hazard menu is 
enabled, you will be able to perform the hydrologic and hydraulic analyses.

2.   To identify your scenario, you will be prompted with a window (see Figure 
4-13) to name your study case and to write a description (optional). When you 
open your study cases in the future, your descriptions will be visible to help 
you differentiate among similar study cases. 


Figure 4-13: Create new study case dialog box. Graphic showing computer 
screenshot of the create a new case study dialog box.


3. The riverine analysis requires defining the study case reaches and running 
the hydrologic analysis: 
a. To begin selecting the stream reaches used in the scenario, use the dialog 
New Study Case shown in Figure 4-14, which will enable you to select the 
stream reaches that you would like to include in the study case. You may use the 
Select Features tool (the button with the arrow icon) to select particular 
stream reaches by clicking on them or draw a box around certain areas to select 
multiple reaches. If you hold down the Shift key, you can select or remove 
additional stream reaches by clicking on them. 
b. To complete stream reach selection and the definition of the study case, 
click OK. The color of the highlighting of the selected streams will change 
when this process is complete. Once you have defined your study case, the 
Hydrologic Analysis option on the Hazard menu is enabled. You can now perform 
the hydrologic and hydraulic analysis. 
c. To begin running the hydrology calculation for the study case stream reaches 
that you have selected, select Hydrologic Analysis on the Hazard menu. HAZUS-
MH will analyze the discharge-frequency relationship for each reach in the study 
case based on USGS data and equations. The hydrology process needs to be 
performed once for each reach in the study region.


Figure 4-14: Stream reach selection. Graphic showing computer screenshot of the 
stream reach selection screen.


4. For the coastal analysis, characterizing the shoreline is required; you will 
provide the flood model with the information necessary to determine which models 
will be run, including frontal dune erosion, What-If, and Runup. To characterize 
the shoreline:
a. Select Shoreline Characterization under the Hazard menu (see Figure 4-15). 
Activate the Startline Radio button in the Shoreline Limits dialog and press 
the Draw button to identify the start point (Shoreline Start). Activate the 
Startline Radio button and press the Draw button to identify the finish point 
(Shoreline Finish) of the shoreline segment to characterize. In between these 
two points, you may add any breaks in the shoreline (Breaklines) where the 
geographic characteristics of the shoreline change. Activate the Breakline radio 
button to draw Breaklines.  


Figure 4-15: Hazard menu. Graphic showing computer screenshot of the hazard 
menu, with the "Shoreline Characterization" selection highlighted.


Sidebar: HAZUS software: The What-If analysis options in the flood module 
include levee assessment, upstream storage, and simplified velocity for the 
riverine analysis. The What-If analysis options include long-term erosion and 
shore protection for the coastal analysis.

b. Select Next and you will be moved to a dialog to define information 
regarding the shoreline characteristics, wave exposure, and 100-year still water 
elevation. The Shoreline Type tab has two combo boxes to define Wave exposure 
(Open Coast, Moderate exposure, etc.) and Shoreline type (rocky bluffs, sandy 
bluffs, little beach, etc.). At the top of the dialog, the user can switch from 
one shoreline segment (if more than one) to another and back using the arrow 
buttons. The 100-Year Flood Condition tab allows you to provide the 100-year 
still water elevation from a Flood Insurance Study. This information is readily 
available online at the FEMA Map store at http://www.fema.gov.

Sidebar: HAZUS software: For the hurricane analysis, there are currently no 
damage or loss estimates for high potential loss facilities, transportation 
lifelines, utility lifelines, or hazardous material storage facilities.   

5. To begin running the hydrology, select Run Hydrology on the Hazard menu to 
launch the hydrologic calculations for the study case stream reaches that you 
have selected. HAZUS-MH will analyze the discharge-frequency relationship for 
each reach in the study case based on USGS data and equations. This information 
is stored at each node for each reach. The hydrology process needs to be 
performed once for each reach in the study region. 
 
6. To begin running the scenario, select Calculate Hazard from the Hazard menu 
and the window shown in Figure 4-15 will appear. 
 
7. To select the analysis type, select the type of hazard analysis you would 
like to run on the pull-down menu. During the hydraulic analysis, HAZUS-MH 
computes a flood elevation and a flood depth grid for each user-defined 
frequency or discharge. You will need to run this analysis for each new return 
period or each new study case. You can run (1) multiple return periods of 10, 
50, 100, 200, and 500 years; (2) a single, user specified return period; and/or 
(3) annualized loss. It is now time to run the analysis. Select Analysis on 
the main menu, and then select Run. The menu shown in Figure 4-16 (graphic 
showing the analysis options menu) should now be displayed.  

8. To select the analysis options, click on the plus and minus signs to expand 
and collapse the lists of available options (see Figure 4-16). Select the 
analyses to be performed, and click OK. The analysis options include general 
building stock damage and loss, essential facilities, user defined structures, 
transportation systems, utility systems, agricultural products, vehicles, 
debris, direct social loss, indirect economic loss, and What-If.  


Figure 4-16: Analysis options menu. Graphic showing computer screenshot of the 
analysis options menu, which shows the list of available options.


Sidebar: Note: The following section explains how to run a flood analysis using 
the HAZUS-MH Flood Wizard. You can download the Flood Wizard from the following 
web site: http://www.fema.gov/hazus/tr_main.shtm. Click on Latest HAZUS Tools 
Now Available, to access the file.


Running a Flood Scenario with the Flood Wizard
To run the HAZUS-MH Flood Wizard, you will need to (1) install the Flood Wizard, 
(2) create a Flood region with the HAZUS-MH Flood module, (3) execute the Flood 
Wizard program, (4) run the Analysis, and (5) view the outputs.  Worksheet 4-2, 
Flood Wizard Outputs, will help you document your efforts.

1. To install the Flood Wizard, insert the Flood Wizard CD (or open the file you 
downloaded) and follow the installation instructions, which should appear as an 
autorun feature. The Flood Wizard Installation menu will appear (see Figure 4-
17).


Figure 4-17: Flood Wizard installation menu. Graphic showing computer screenshot 
of the welcome screen for the InstallShield Wizard.


Click Next to proceed. The installation wizard will next show the destination 
directory that is the same as where HAZUS-MH is installed. Click Next to 
proceed. The installation will proceed with the progress indicated by the status 
bar in the center of the screen. The installation is complete when the Finish 
option becomes available (see Figure 4-18: graphic showing that the 
InstallShield Wizard is complete). Click Finish.


Figure 4-18: InstallShield Wizard complete. Graphic showing computer screenshot 
of the completion screen for the InstallShield Wizard.


2. If you dont have a HAZUS-MH Flood region available, you must create one 
using the HAZUS-MH Flood module. Once a region is available, exit HAZUS-MH and 
execute the Flood Wizard. 

3. To execute the program, select Start from your windows menu, then 
Programs and FEMA Risk Assessment System. Click on the Flood Wizard icon.  
The Flood Wizard menu box should become available (see Figure 4-19). Go to the 
Analysis menu and select Run.


Figure 4-19: Flood Wizard menu box. Graphic showing computer screenshot of the 
Flood Wizard menu box.


Click over Flood Data in the menu to access the options to select an available 
Study Region, define the Flood Maps (Q3, FIRM, or user defined), and a Digital 
Elevation Model (see Figure 4-20).


Figure 4-20: Flood data menu. Graphic showing computer screenshot of the Flood 
Wizard menu box, with the Flood Data dropdown menu shown.


4. To run the analysis, select Analysis from the main menu, then Run (see 
Figure 4-21). The Flood Wizard will take a few minutes to process the data and 
provide the results in tabular and map formats.


Figure 4-21: Analysis main menu. Graphic showing computer screenshot of the 
Flood Wizard menu box, with the Analysis dropdown menu shown.

 
5. To view the results, select any of the options under the Results menu. The 
Flood Wizard provides building exposure, content exposure, total exposure, and 
building count for the general building stock in the floodplain. It also 
provides building loss, content loss, and total loss for the economic loss of 
the general building stock.


Run a Hurricane Scenario
To run a probabilistic hurricane scenario, follow the instructions below:
1. To activate the scenario wizard for a hurricane event, click on Hazard 
Scenario on the Hazard menu. Select Next. The Scenario Operations menu should 
now be displayed as shown in Figure 4-22.


Figure 4-22: Scenario operation menu. Graphic showing computer screenshot of the 
scenario operation menu, with "Probabilistic" selected.


2. To select the probabilistic hazard, click on Probabilistic. Select Next 
and you will be asked if you want to make this scenario active. Select the 
button to make it active and then click Next. Finish the scenario by selecting 
Finish. 

3. To run the analysis, select Analysis on the main menu, and then select 
Run. The menu shown in Figure 4-23 should now be displayed. Three types of 
output analysis can be performed:  direct physical damage, induced physical 
damage, and direct social and economic loss. Select the analyses to be 
performed, and click on Run Analysis.


Figure 4-23: Analysis options menu. Graphic showing computer screenshot of the 
analysis options menu, which shows the list of available options.


Obtain Loss Estimation Results from HAZUS-MH Scenarios
After the hazard scenario has been run, you can access HAZUS-MH outputs by 
selecting Results on the main menu. HAZUS-MH produces results in three 
formats: tables, maps, and summary reports. Select Summary Reports on the 
Results drop-down menu to review your outputs. A summary of the outputs 
available for each module is provided as several Job Aids (Appendix F). The 
outputs also can be viewed individually. Select the output of interest to view 
the individual table. For example, select Ground Motion on the Results drop-
down menu to view the ground motion by Census tract throughout the study region. 
To map the ground motion, select a column in the table, such as peak ground 
acceleration (PGA), and click Map at the bottom of the page.

Sidebar: Note: You can download the Risk Assessment Tool from the following web 
site: http://www.fema.gov/hazus/tr_main.shtm.  Click on Latest HAZUS Tools Now 
Available, to access the file.


Run the Risk Assessment Tool (Task 4.3) 
FEMA has developed a companion software tool to HAZUS-MH called the HAZUS-MH RAT 
to help you produce your risk assessment outputs for earthquakes, floods, and 
hurricanes. This tool was developed as a third-party model to support HAZUS-MH 
and is used to display the outputs from the HAZUS-MH risk assessment in an easy-
to-use format. The RAT pulls natural hazard data (Steps 1 and 2); inventory data 
(Step 3), and loss estimate data (Step 4) into pre-formatted summary tables and 
text. These summaries can support the presentation of data to (1) decision-
makers and other stakeholders and (2) in your mitigation plan. 
 
To run the HAZUS-MH RAT, you will need to: (1) install the RAT, (2) execute the 
program, and (3) view the outputs.

1. To install the RAT, insert the RAT CD (or open the file you downloaded) and 
follow the installation instructions, which should come up as an autorun 
feature. The RAT installation menu will appear (see Figure 4-24). Click Next 
to proceed. The installation menu will next prompt you for a destination 
directory (see Figure 4-25). Type the directory name if the default directory is 
not your preference. Click Next to proceed. The installation will proceed with 
the progress indicated by the status bar in the center of the screen. The 
installation is complete when the Finish option becomes available (see Figure 
4-26). Click Finish.


Figure 4-24: RAT installation menu. Graphic showing computer screenshot of the 
RAT installation menu.


Figure 4-25: RAT destination directory. Graphic showing computer screenshot of 
the RAT destination directory.


Figure 4-26: RAT installation complete. Graphic showing computer screenshot of 
the RAT installation completion screen.


2. To execute the program, open your study region in HAZUS-MH. Before running 
the RAT, make sure that you have run the hazard scenarios in Step 4. There are 
two ways in which to begin using the RAT. If you selected earthquake as one of 
your hazards, you may run the RAT as a third party model like Aloha or FLDWAV. 
Begin by switching to the earthquake model if you are currently viewing the 
flood or hurricane model.  Select Analysis from the main menu, select 3rd 
Party Models, and then select Risk Assessment Tool (see Figure 4-27). 
Alternatively, if earthquake is not one of your study regions hazards, you may 
run the RAT without using the HAZUS-MH menus. Open your study region in HAZUS-
MH. Select Start from your windows menu, then Programs and FEMA Risk 
Assessment System. Click on the RAT option (see Figure 4-28). The RAT menu box 
should become available (see Figure 4-29, graphic showing the RAT menu box). 
Select the County of interest and the Hazard of interest. The RAT can be run for 
one county and one hazard at a time. When you are finished, select OK. The RAT 
will take a few minutes to process the data and provide results.


Figure 4-27: Third party model menu. Graphic showing computer screenshot of the 
HAZUS-MH main menu, on which the "Analysis" dropdown list is shown and the 
"Third Party Models" selection has been highlighted.


Figure 4-28: RAT program location. Graphic showing computer screenshot of the 
Start button programs list, on which the "FEMA Risk Assessment System" and "Risk 
Assessment Tool" selections are highlighted.


Figure 4-29: RAT menu box. Graphic showing computer screenshot of the RAT menu 
box.


3. To view the outputs, scroll through the document (see Figure 4-30) that has 
been generated by the RAT. The outputs include maps and tabular data that can be 
placed directly into a mitigation plan. The document can be printed and exported 
using the features above the report. A summary of the outputs available for the 
RAT is provided as a Job Aid 4-4 (Appendix F).


Figure 4-30: Risk assessment tool report. Graphic showing computer screenshot of 
the risk assessment tool report screen, which contains a copy of the report.

Congratulations! You have now completed running the RAT and have obtained a RAT 
report.  


Calculate Exposures for Hazards Not Included in HAZUS-MH (Task 4.4) 
To evaluate exposure using the HAZUS-MH GIS tools and inventory databases, you 
will use the hazard maps created in Step 2, and overlay them with the inventory 
provided in HAZUS-MH. To overlay a hazard map, select File, then Add Data 
and browse to a selected hazard map. If Step 2 was completed successfully, the 
hazard map should be in the correct format and projection. The map will appear 
over the study region and become a layer on the right. All of the inventory 
datasets are available under the Inventory menu. Review Step 3 for more 
information on viewing these datasets. Map the inventory of interest over the 
hazard map and determine what is at risk. Identify subsets of data by selecting 
inventory layers using the icon with an arrow.

Congratulations! You have now used HAZUS-MH to map the hazards not available in 
HAZUS-MH and overlaid them with the inventory provided by HAZUS-MH to estimate 
exposure. 


Evaluate the Results of the Risk Assessment (Task 4.5)
You have now obtained risk assessment outputs as either quantitative loss 
estimates for the earthquake, flood, and hurricane hazards or quantitative 
estimates of exposure for other hazards that you are able to map (for example, 
landslide susceptibility and wildfire hazard areas). The next step is to 
evaluate these data for reasonableness and to compare the risks associated with 
each hazard.

  
Consider and Review Your Loss Estimate Results
This activity will help you determine whether the results from the loss 
estimation study are reasonable and ready for use. To assess the results of your 
risk assessment, it is recommended that you get input from your risk assessment 
team, compare HAZUS-MH outputs to anticipated results (e.g., based on historic 
losses), and consider any hazard expert input on the results you have obtained. 
Team members and experts can assess the hazard profiles you have prepared, maps 
you have developed, and risk assessment output tables that are available now. 
They can help you document any concerns, revise any inputs and re-run results, 
or document that the results are within the margin of error suitable to support 
your mitigation strategy.

To consider and review the results of your risk assessment, take the following 
steps.  
1. Use professional judgment. You can use the professional judgment of your risk 
assessment team to evaluate if the results are within a range of the value you 
expected or within a margin of error that you feel is acceptable for risk 
assessment purposes.  

2. Review available technical documentation. You also may want to review the 
documentation of each model provided with the HAZUS-MH user and technical 
manuals.

3. Ask stakeholder experts for input. It is a good idea to involve appropriate 
stakeholder experts during all phases of the mitigation planning process.  For 
example, if you are running a risk assessment for a flood, review the HAZUS-MH 
results with the floodplain manager for the study region.  Such experts can 
assist in data collection, data evaluation, and output consideration. They also 
can help you ground-truth the results of your loss estimation based on their 
knowledge of past events and their ongoing efforts regarding the hazard of 
concern. These experts also may support your text regarding the hazard profiles, 
risk assessment outputs, and long-term data needs to refine your analyses.

4. Consider if development or other factors are impacting your study region. A 
Level 1 analysis is based on HAZUS-MH provided data. These data include 
assumptions regarding the hazard characteristics in your area, which may require 
refinement (Step 2, Identify Hazards) and inventory data that is based on 
national and regional databases (Step 3, Inventory Assets). If your local 
conditions change or vary significantly from the HAZUS-MH provided data and you 
have completed a Level 1 analysis, you may identify areas of your risk 
assessment that require additional explanation or refinement. Some of these 
refinements may be feasible for this portion of your risk assessment. Other 
refinements may become part of your long-term data management or improvement 
efforts and may warrant a mitigation strategy goal or action to help improve 
data and assumptions for hazards that are of interest and concern in your 
community. 
 
5. Revisit your risk assessment, as necessary. If items 1 through 4 raise 
concerns that you feel must be addressed, you may want to revisit Steps 2, 3, 
and 4 (especially, hazard characterization inputs and inventory inputs). If you 
feel that the results are reasonable for your purposes, you can continue forward 
to use your risk assessment outputs.

After completing your evaluation of results and making adjustments as needed to 
your hazard and inventory data, you can rerun HAZUS-MH, as necessary, to obtain 
revised results and outputs. Remember that these evaluation activities can be 
continued as your mitigation planning efforts evolve and as local data and 
hazard-specific knowledge improves. 
 
After you complete your first risk assessment effort, it is important to keep 
your asset inventory and hazard data current so that you are ready when you need 
to update your risk assessment (e.g., after a major hazard event or to comply 
with the schedules provided in DMA 2000). Data maintenance and integrity are 
critical to successful HAZUS-MH implementation.


Summary
After completing Step 4, you should have a good idea which assets are subject to 
the greatest potential damages and which hazards are likely to produce the 
greatest potential losses or present the greatest hazard exposure. Table 4-1 
summarizes the activities and outputs for this step.


Table 4-1: Estimate Losses Activities and Outputs Checklist
This table consists of three columns: Activity, Output, and Check Completed 
Items. The Check Completed Items column has been left blank for notations. The 
information in the table is summarized as follows:

Activity: Integrate hazard profile data for HAZUS-MH Level 2 
(Task 4.1)	
Output: Updated HAZUS-MH profile data
	
Activity: Run HAZUS-MH scenarios 
(Task 4.2)	
Output: Tables, maps, and summary reports; Worksheets 4-1 and 4-2
	
Activity: Run the Risk Assessment Tool
 (Task 4.3)
Output: Risk Assessment Tool Report	

Activity: Calculate exposure for hazards not included in HAZUS-MH 
(Task 4.4)	
Output: Inventory at risk 

Activity: Evaluate the results of the risk assessment
 (Task 4.5)	
Output: Reasonable HAZUS-MH outputs 	


Complete any missing items in your checklist, and then continue to Step 5. 

Go TO step 5: CONSIDER MITIGATION OPTIONS


WORKSHEET 4-1: INVENTORY AT RISK ESTIMATES
Worksheet 4-1 will help you to organize your estimated losses obtained during 
Step 4. 

The worksheet is in the form of a table. The table title is Loss Estimation 
Values. 
There are two main columns: Inventory Asset Category (for example, Essential 
Facilities and Transportation Lifeline Systems) and Items Used for HAZUS-MH 
Model.

There are three columns under "Items Used for HAZUS-MH Model": Earthquake, 
Flood, and Hurricane. All three provide for entries in thousands of US dollars. 
Inventory Asset Category entries for Hurricane that are not estimated by the 
hurricane model are noted as "NE." 

			
Worksheet 4-2. Flood Wizard Outputs
Use Worksheet 4-2 to record the values obtained after running the Flood Wizard 
analysis.

The worksheet is in the form of a table. For the 500-Year Return Period and 100-
Year Return Period, rows are shown for the values of building exposure, content 
exposure, total exposure; building loss, content loss, and total loss in 
floodplain. Rows are also included for the number of buildings in the 
floodplain.

Eight columns are devoted to the following categories: Population, Residential, 
Commercial, Industrial, Agriculture, Religion,	Government, and Education. 

		
EXAMPLE 4-1:  ESTIMATE LOSSES

HURRICANE LOSS ESTIMATE FOR AUSTIN, TEXAS
The hurricane hazard loss estimate is presented below.

Risk Assessment Data Collection.  HAZUS-MH provided inventory data were 
augmented for Austin-critical facilities. Therefore, the critical facilities 
considered in this risk assessment included Austin-critical facilities, 
essential facilities, special facilities, HazMat facilities, transportation 
lifeline systems, and utility lifeline systems, as shown in the table below. 
Population data were taken from the HAZUS-MH provided data, which is based on 
the most recent Census conducted in 2000; local data correlated closely to the 
HAZUS-MH Census data.  

Hazard Model Development. Because this hazard was analyzed using the HAZUS-MH 
software, additional model development efforts were not required. No local 
hazard data to update the model components were identified as necessary or 
available.

Risk Assessment Methodology. The hurricane module of HAZUS-MH was used and 
provided loss estimations for: General building stock and critical facilities. 
Other loss estimates included displaced households and shelter requirements. The 
100- and 500-year mean return period (MRP) events were analyzed. Annualized 
losses also were estimated.

Estimated Damages and Losses. Property damage due to the hurricane hazard was 
summarized by occupancy class in the table below. The total estimated loss for a 
hurricane with a severity equal to a 500-year MRP was approximately $1.4 
billion. Residential buildings accounted for about 86 percent of the total 
losses for this event. Because of differences in building construction, 
residential structures were more susceptible to wind damage than commercial and 
industrial structures. The damage counts included buildings damaged at all 
severity levels from slight damage to total destruction. The total dollar damage 
represented the overall impact to individual buildings at an aggregate level. 

Table: Estimated Damages/Losses to General Building Stock For Hurricanes In 
Austin, Texas. Dollars rounded to the nearest hundred thousand.

Occupancy Class: Residential
100-year Event Damages: 159.7 million dollars
500-year Event Damages: 1,232.5 million dollars

Occupancy Class: Commercial
100-year Event Damages: 6.1 million dollars
500-year Event Damages: 178.7 million dollars

Occupancy Class: Industrial
100-year Event Damages: 0.6 million dollars
500-year Event Damages: 29.7 million dollars

Total
100-year Event Damages: 166.4 million dollars
500-year Event Damages: 1,440.9 million dollars


The hurricane module also provides shelter requirement estimates. For a 100-year 
event, hurricane shelter requirements are estimated to be negligible. For a 500-
year event hurricane, households displaced are estimated to be 1,750 (about 
5,000 people); short-term shelter needs are estimated to be required for 460 
persons.

The next table presents the impacts to critical facilities associated with the 
hurricane hazard in Austin, TX. As shown in the table, the damage impact of the 
hurricane hazard on critical facilities is anticipated to be minor for both the 
100- and 500-year MRP events.
The loss ratio represents the percent of the building value that likely would be 
incurred to repair or restore the facility to its original, pre-hazard state.

HAZUS-MH also estimates average annualized losses, which represent the average 
loss that can be expected per year.  The total expected average annualized loss 
associated for hurricanes is estimated at $16.9 million. The average annualized 
loss by occupancy class associated with hurricanes is: 
--$14.2 million for the residential occupancy class (accounting for 84 percent 
of the total annualized losses)
--$2.3 million for the commercial occupancy class
--$0.4 million for the industrial occupancy class


Table: Critical Facility Exposure and Loss Ratios for Hurricanes in Austin, 
Texas

Table description: Three main columns: Facility Class, 100-Year Event, and 500-
Year Event. Under the 100-Year Event and 500-Year Event sub-columns, there are 
two sub-columns: Number Exposed/At-Risk and Loss Ratio.


The HAZUS-MH hurricane model does not estimate transportation and utility system 
losses or impacts. It also does not estimate indirect economic losses. 
Therefore, these results are not presented for this hazard.  

The figure below shows the dollar loss density estimates for a 500-year MRP 
event for the hurricane hazard for the commercial occupancy class. As indicated 
on the figures legend, areas in darker colors indicate areas where greater 
losses are incurred per square mile of land.

Figure 4-31: Hurricane loss density for Austin, Texas, for a 500-year hurricane 
event (Commercial Occupancy Class). Map showing the geographic distribution of 
commercial loss density in Austin.