Notes
Slide Show
Outline
1
HAZUS-MH 1.1 Workshop
  • Michael S. Scott, PhD
  • msscott@salisbury.edu


  • August 10, 2005
2
Section 1:  Introduction
  • The 1st meeting of the Maryland HAZUS User’s Group?
  • What is the ESRGC?
  • Project background, goal, & method
  • Vulnerability project results
  • Conclusions
  • Goals of this workshop
3
What is the ESRGC?
  • Eastern Shore Regional GIS Cooperative
  • Mission: To support the development of GIS technology in municipalities and counties on Maryland’s Eastern Shore
  • Funded by the Regional Councils of the Mid-Shore and the Lower Shore
  • www.esrgc.org
4
Project Background
  • Vulnerability – Potential for loss
  • Situated at the intersection of the physical hazard and the social system
  • Unfortunately, not simply a matter of map overlay
    • Depth of flood, recurrence, structure characteristics, mitigation techniques, etc
  • Very complex, interrelated system
5
Project Goal
  • Complete a General Building Stock Damage and Loss analysis for a 100-year flood event for each county in the State, including the City of Baltimore, using the latest HAZUS-MH Flood module


6
Method
  • For each jurisdiction, calculate 100-year flood zone using HAZUS-MH 1.1, intersect with the amount and type of building stock to calculate loss potential
  • Run both riverine and coastal where appropriate
  • Complete a Level 1 HAZUS analysis
    • Using default data
    • Consistent quality across jurisdictions
7
Results
  • Report will be made available at www.esrgc.org later today


  • Over 1,328 square miles of Maryland are vulnerable to the 100-year flood
  • 15 jurisdictions (of 24) are vulnerable to coastal flooding
8
Totals for Maryland
  • Building stock exposure (in 2001): $7.99 billion
  • Building damage in sq ft: 109,665,000
    • Worcester:  over 21 million or 19.4% of state total
    • Somerset:  5.7 million but 68% is predicted to be “substantial
  • Building damage in numbers of structures: 44,755
    • Anne Arundel: 7,038 buildings damaged
  • Direct economic losses: $8.12 billion
    • Prince George’s:  $1.28 billion
    • Prince George’s, Anne Arundel, and Worcester equal almost 40% of Maryland’s total loss potential
9
 
10
 
11
 
12
Study Conclusions
  • Vulnerability to flooding in Maryland is not evenly distributed
    • Prince George’s, Worcester, Anne Arundel, Montgomery, Washington, Howard, Baltimore County, and Baltimore City disproportionately effected
  • Areas with large vulnerable areas happen to be forecasted for increased development
    • Dorchester, Somerset, Talbot, Caroline, Worcester
  • There is a need to look more closely at particular trouble spots to further refine the analysis
13
Goals of the Workshop
  • Introduce the capabilities and limitations of HAZUS-MH
  • Discuss the functionality of HAZUS-MH
  • Examine the steps necessary to complete a Level 1 HAZUS-MH model run
  • Analyze the results of the recently-completed HAZUS-MH model runs for each county
  • Discuss the next steps in vulnerability modeling
14
Section 2:  Model Expectations
  • HAZUS-MH 1.1 – Level 1
  • What it is and what it isn’t
  • Capabilities
  • Variables for consideration
  • How it works
  • How you get it
  • Hardware requirements
  • Software requirements
  • Installation hints
15
HAZUS-MH 1.1 – Level 1
  • Designed to estimate a wide range of losses from flood (as well as other hazards)
  • Internally, several stochastic flood models provide the engine, as well as ArcGIS 9.0.1
  • Uncertainty/error are significant but not quantified in a Level 1 analysis
  • New version scheduled to be released in late summer/early fall
16
What it is…
  • An rough estimate of potential losses
  • A very useful and consistent tool to measure differences in vulnerability across and between counties
  • A dynamic modeling tool that allows the user to ask “what if” questions
  • Helpful to prepare for the inevitable
  • Complicated and computer-intensive
17
What it isn’t…
  • A vulnerability crystal ball
  • Calibrated to your specific economic situation
  • Any better than its inputs
  • A substitute for a engineering-based flood study
  • Easy to use or interpret
18
Capabilities
  • Calculating flood depths in both riverine and coastal contexts
  • Modeling losses to the census block level
  • Examining multiple dimensions of loss
  • Analyzing multiple recurrence intervals or specific discharge amounts
  • Viewing up to 4 counties simultaneously
19
Variables for Consideration
  • 30-meter digital elevation model
  • General Building Stock
    • 2000 Census of Housing data for buildings
    • Dun & Bradstreet data for non-residential buildings
    • US Department of Energy for regional differences in square footage, construction types, etc
  • Limited number of stream gauges
20
How it works:  Determine Riverine Flood Depth
  • Creates flow grid from DEM
  • Identifies stream reaches from flow grid
  • Associates each reach with a drainage area
  • Identify stream gauges in drainage area
  • Approximate the floodplain for each reach
  • Create a set of flood depth cross sections
  • Interpolate from cross sections to grid cells
21
How it works:  Determine Coastal Flood Depth
  • Characterize the shoreline (i.e. bluffs, dunes, erosion control)
  • Enter flood depths per recurrence interval plus wave height (if appropriate)
  • Run one or more coastal flood models
    • Dune/bluff erosion, wave height, and wave runup)
  • From models, determine flood depth
22
How it works:  Loss Estimates
  • Uses depth-damage curves that need:
    • Occupancy class, foundation type, and assumed first floor elevation
    • Depth of flooding throughout the census block
  • Uses NFIP claims to create depth-damage curves for “typical” construction types
  • Matches up buildings in a block and depth within a block to depth-damage curves to estimate damage
23
How you get it
  • Request a copy from FEMA
    • http://www.fema.gov/hazus/
  • Set of DVDs and CDs
    • Data DVDs are regional
24
Hardware Requirements
  • FEMA recommended configuration
    • 2.5 Ghz processor
    • 512 GB RAM
    • 80 GB HDD
    • 800x600 video card
  • ESRGC configuration
    • 3.4 Ghz processor
    • 2 GB RAM
    • 80 GB HDD
    • 128 MB, 1600x1200 video card
    • Still takes approximately 8-10 hours per model run
25
Software Requirements
  • HAZUS-MH 1.1
    • Avoid version 1.0 if at all possible
      • Processing takes 3-4 times as long (several days for one county)
      • Limit on raster processes
      • Very buggy
  • ArcGIS 9.0 – Service Pack 1
    • Current SP is 3…must keep old version of Arc 9
  • Must have ESRI’s Spatial Analyst
  • Windows XP, Service Pack 1
    • SP2 causes problems
26
Installation Hints
  • Start with a fresh copy of Windows and ArcGIS (no SP 2)
  • Copy the entire data DVD on to the hard drive
    • Must manually change the registry entry to point to the new location
  • Increase your virtual memory to at least 4 GB
  • If you are getting more than a couple hydrology/hydraulic errors in a county, it’s possible you have corrupted installation disks
  • If you have disks from before Feb 28, you need a major patch
  • Be sure to have administrator privileges
27
Section 3:  Modeling steps
  • Create a study region
  • Study region set-up
  • Study case set-up
  • Riverine flooding parameters
  • Coastal flooding parameters
  • Determine riverine and coastal hazard
  • Analysis/loss estimation
  • Report results
  • Or…import a model run that’s already done!
28
Creation of a Study Region
  • Choose your state
  • Choose your county
    • All flood modeling is done at the county level using census blocks, even if you don’t want to analyze an entire county
  • Maximum of 4 counties
    • Implications in studying watershed vulnerability
29
 
30
 
31
 
32
Study Region Setup
  • Decide on type of flooding
    • Riverine, coastal, or both
    • Makes a difference in the size and shape of the DEM you’ll need
  • Download DEM from NED online
    • The button to “Navigate directly to NED download” does not seem to be working
    • Go to http://seamless.usgs.gov and enter the bounding coordinates manually
  • Set the DEM data paths
    • Will begin to build the hillshade visualization
33
 
34
 
35
 
36
 
37
 
38
 
39
 
40
 
41
Study Case Set-Up
  • Calculate stream reaches
    • Must chose minimum drainage area
    • Essentially a level of precision
    • Limited to computer processor and time
    • Doesn’t modify the chosen floodplains
  • Create study case
    • Name and description
    • Can have multiple study cases per county
      • Different parameters per study case
    • Selecting reaches and coastlines to be included in the study case.
      • Be sure to select all the reaches and coastlines up front…you can’t add more later
42
 
43
 
44
 
45
 
46
 
47
 
48
Riverine Flooding Parameters
  • Hydrologic analysis
    • Individual drainage basins can be run separately
    • All in a county can be selected at once
    • If the analysis fails, there is a log to check what stream reach it failed on
      • This allows you to remove the offending reach
49
 
50
Coastal Flooding Parameters
  • Shoreline characterization
    • Type of shoreline
      • Rocky, large/small dunes, flood control structure
      • Controls what models will run
    • Flood height
      • With or without wave setup
      • 10, 50, 100, and 500 year flood

51
 
52
 
53
 
54
 
55
Determine Riverine and Coastal Hazard
  • By recurrence interval
    • 10, 50, 100, and 500
    • Single recurrence interval
  • By discharge value
  • By annualized loss


56
 
57
 
58
 
59
 
60
 
61
 
62
 
63
Analysis/Loss Estimation
  • Possibilities range from building stock damage to casualties to essential facility damage to debris removal costs
  • This study focused on general building stock damage and loss, as well as indirect economic losses
    • Includes damage by type and by occupancy, count of damaged buildings, and economic losses such as structural damage, contents damage, relocation costs, wage losses, etc.
  • Some analysis results are dependent on others but the model accounts for that automatically
64
 
65
Report Results
  • Results are reported with maps and tables
  • Every variable calculated can be mapped by census block
  • Crystal Reports automatically generates summary reports
    • Exportable to Excel, etc
66
 
67
 
68
 
69
 
70
 
71
 
72
 
73
 
74
Import a Study Region
  • Luckily, most of this work has been done for you!
  • Can import the model run used for the state study to examine your county’s vulnerability
  • Any changes to the model parameters will require a re-run.
75
 
76
Major HAZUS Errors/Bugs
  • In the past:
    • Counties without any results
    • Stream reaches that cannot have hydrologic analysis completed
    • Stream reaches that cannot have hydraulic analysis completed
    • “Riverine and Coastal” model runs returns only coastal results
  • Most of the major errors have been fixed with the patch released in March 2005
  • Now, the concerns turn to the more insipid error:  those within the results
77
Section 3:  Analysis of Results
  • Examine the output in ArcGIS 8.3
  • Understanding the Flood Depth Grid
  • Working with Census Blocks
78
Let’s get into the GIS!
  • Insert CD and copy contents to the D: drive under studentfiles
  • Open ArcMap
  • Load in:
    • reg_bound/reg_bound_utm18
    • flood_bound/flood_bound_utm18
    • V:\hazus_reports\grids\yourcounty\rpd100*
79
Understanding the Flood Depth Grid
  • Difference between the flood elevation and the ground elevation at each grid cell
  • Water depth at each cell
  • Some results are suspect
    • Backwater areas
    • Pools at confluences
    • Problems with 30-meter DEM
      • Bridges as dams, for example
      • Won’t generic LiDAR make this worse?
80
Working with Census Blocks
  • Load:
    • dam_occ/res.shp
      • Thousands of square feet of residential building damage
    • dam_occ_cnt/res.shp
      • Numbers of residential buildings damaged
    • dam_type/wood.shp
      • 1000s of square feet of wood building damage
    • dam_type_cnt/wood.shp
      • Numbers of wood buildings damaged
    • econ_full_total/total.shp
      • Thousands of dollars in direct economic losses from buildings
81
Working with Census Blocks
  • Smallest unit of census data released to the public
  • Blocks are not a uniform size but try to use visible landscape features for definition
  • Have to assume that population is evenly distributed
  • It’s possible to have a block intersect the flood zone but have no damage
82
Working with Census Blocks
  • Dam_occ/res.shp (1000s of sq ft)
    • CensusBloc – Block ID number
    • Length and area are WRONG
    • Totalsquar – total amount within flood area (including undamaged)
    • Sqftwithsu – amount with substantial damage (>50% damaged)
    • UndamagedS – amount undamaged
    • SqftDmg1to – amount damaged between 1 and 10%
    • SqftDmg11to – amount damaged between 11 and 20%
    • TotalDam – total amount damaged
83
Working with Census Blocks
  • Dam_occ_cnt/res.shp (Numbers of structures)
    • CensusBloc – Block ID number
    • Length and area are WRONG
    • TotalBuild – total amount within flood area (including undamaged)
    • BldgswithS – amount with substantial damage (>50% damaged)
    • UndamagedB – amount undamaged
    • PctDmg1to1 – amount damaged between 1 and 10%
    • PctDmg11to – amount damaged between 11 and 20%
    • TotalDam – total amount damaged
84
Working with Census Blocks
  • econ_full_total/total.shp (Thousands of dollars)
    • TotalLoss – total direct economic losses
    • BuildingLo – cost of building damage
    • ContentsLo – cost of damage to building contents
    • InventoryL – cost of damage to inventory
    • Relocation – cost of temporary relocation
    • IncomeLoss – cost of lost owner’s income due to displacement
    • RentalInco – cost of lost rental income
    • WageLoss – cost of lost wage income
    • DirectOutp – unknown
    • Employment – unknown
85
 
86
Section 4:  Next Steps
  • Level 2 Analysis
    • Special tools
    • Data needs
  • Comparisons
    • Recurrence Intervals
    • Digital vector flood maps
  • Let skepticism be your guiding force
87
Level 2 Analysis
  • Much more detailed and realistic
  • Abandons national, default datasets for local, specialized information
  • BIT and FIT
    • Building Information Tool
      • Used to get detailed building stock info into HAZUS
    • Flood Information Tool
      • Used to get flood extents and depths into HAZUS
  • Time consuming and technical but probably worth it.
88
Level 2 Data Needs
  • More accurate DEM
    • LiDAR, 2-meter cell size?
    • Unsure about the effect of local minima and maxima
  • Detailed inventory of the built environment
    • Structures
      • Location, occupancy, construction, height to 1st finished floor, characteristics
    • Essential facilities
    • High potential loss facilities
    • Lifelines
89
Level 2 Data Needs
  • More accurate flood hazard data
    • Detailed DEM
    • Series of flood elevation cross sections
    • Boundary of flood zone
    • Detailed shoreline characterization
90
Comparisons
  • Comparison between 50-, 100-, and 500-year flood zone extents and depths
    • Often considered more vulnerable when a large distance between 100- and 500-year is found (people tune out to flood warnings)
  • Comparison between HAZUS output and DFIRMs/Q3 data
    • St. Mary’s example
  • Comparison between HAZUS output and MDProperty View
    • Be very careful…
91
And finally…
  • Be very skeptical of HAZUS-MH 1.1 until you have a reason not to be
    • With the number of critical errors present in the first iteration of this release, one has to wonder what errors lie beneath
    • No quantification of uncertainty
    • It’s just too new…hasn’t been properly vetted by the scientific community in a variety of situations