Using GIS to Analyze Exposure & Losses from Disasters (Hurricane Storm Surge) Presented by Craig Eissler, Texas Geographic Society TDEM Emergency Management Conference 2011, San Antonio, TX

Are Your Community Assets at Risk? A: IDENTIFY your INVENTORY  Man-made Structures  Population  Natural Systems B: PROFILE the HAZARDS  Flood (Riverine/Inland)  Hurricane Storm Surge (Coastal)  [Others] C (A+B): ASSESS the VULNERABILITY (of your Inventory to the Hazards)  Exposure Analysis  Loss Estimation Analysis What assets do we have? What assets do we have in hazard areas? Of the assets in hazard areas, what might be the impact? What hazards do we have? } } …Ultimately, our objective is to conduct a Vulnerability Assessment (C). But, we will need to answer some preliminary questions first (A & B). We will use GIS to do so.

What is GIS? Geographic Information Systems Spatial Data (Geographic Data; The Map) Attribute Data (Tabular Data; The Database) 3 “linked” Where is it?What about it?

Analyze and manage features or phenomena on the earth -- spatial analysis! Create maps that illustrate your analysis Make better decisions by factoring in the “location” components Why Use GIS? Why GIS for Risk Assessment? Hazards occur somewhere on earth Inventory Assets are somewhere on earth

Environmental Systems Research Institute (ESRI) ArcGIS: (ArcView, ArcEditor, ArcInfo) NOTE: There are many other GIS products on the market from other vendors

1.IDENTIFY your INVENTORY  Man-made structures Buildings o Essential & Special Facilities Infrastructure  Population Census 2010 by Census Block/Tract Current Year Estimates and Future Year Projections  Natural systems Natural Resources Habitat & Ecosystems POPULATION DATA Types: Best: 2010 Next Best: 2000 (soon to be obsolete) and/or Current Year Estimates (if in-between decennial Census) Note: Future Year Projections may be meaningful for analyzing development trends What Assets do we have in our Community?

POPULATION DATA (and Other Demographic & Economic Data) Spatial DataAttribute Data Note: Current 2010 TIGER/Census Data is Redistricting version

2010 TIGER Data (Boundaries) SPATIAL DATA 2010 Census Data (Population) ATTRIBUTE DATA Source: U.S. Census Bureau Source: Texas State Data Center GIS Shapefile MS-Excel file Re-format Join Field Join = Census Block boundaries Census Block Population The Process

Join = Total Population by Census Block (for Brazoria County)

Spatial Data: 2010 Census Boundaries (TIGER) Note: Streets also are included in some TIGER Datasets but we will not need that …from U.S. Census Bureau Web Site

1.Select the Census Boundary (at the most detailed level you want to work with) 2A. Then, for what State? 2B. And, for what County? Spatial Data: 2010 Census Boundaries (TIGER) Download! …in Shapefile GIS format

Spatial Data: 2010 Census Boundaries (TIGER) GIS Shapefile format works right away in GIS! Filename = tl_2010_48039_tabblock10 ‘GeoID10’ will be the “Common Field” we use to Join with the Population Data

Attribute Data: 2010 Census Data (Demographics) Personal Note: Difficult Site to Use; We will use an Alternative Site factfinder2.census.govNEW!

Attribute Data: 2010 Census Data (Population) Texas State Data Center Click: Data Menu

Attribute Data: 2010 Census Data (Population) …scroll down: Currently, the Redistricting Data is all that is available It only provides some basic demographic data, but does include Total Population (and Housing Units) down to the Census Block level Note: Be careful that you use 2010 Data! Data Menu:

Attribute Data: 2010 Census Data (Population) 1. Click: Raw Data 2. Click: Comma Delimited (CSV) Files

Attribute Data: 2010 Census Data (Population) 3.Click: Individual County option 4.Click: …the actual County to Download it …in.csv format

Attribute Data: 2010 Census Data (Population) This file needs some “massaging” in order to work correctly w/ our TIGER Data in GIS Notice the ‘GeoID10’ as the “Common Field” we use to Join with the Population Data

IMPORTANT: The Field Format of the GeoID Fields are different in each of the Datasets: Spatial Data / Census Blocks: GeoID Field is Text Attribute Data / Population: GeoID Field is Numeric Since these will NOT Join unless they are the same, we need to make this change. We will make the change to the Population Data 1. Change the.csv extension to.txt 2. Launch MS-Excel: File > Open the Census Data in.txt format 3. Excel Wizard: Add “Comma” as a Delimited format; Next 4. Excel Wizard: Click on GeoID Field and change to Text format; Finish 5. Save as Excel (.xlsx) format 1. 2.

1. Change the.csv extension to.txt 2. Launch MS-Excel: File > Open the Census Data in.txt format 3. Excel Wizard: Add “Comma” as a Delimited format; Next 4. Excel Wizard: Click on GeoID Field and change to Text format; Finish 5. Save as Excel (.xlsx) format 3. 4.

5. Save in MS-Excel Format (.xlsx)

2010 TIGER Data (Boundaries) SPATIAL DATA 2010 Census Data (Population) ATTRIBUTE DATA Source: U.S. Census Bureau Source: Texas State Data Center GIS Shapefile MS-Excel file Re-format Join Field Join = Census Block boundaries Census Block Population The Process * We Are Here!

JOIN the Spatial Data: 2010 Census Boundaries (TIGER) to the Attribute Data: 2010 Census Data (Demographics) in the GIS Note: After Joining, you may choose to Save The Join as this new Layer Right-click Layer > Data > Export Filename = ‘Census 2010 Population’ …or whatever Note: Re-Project it also since we will be performing analysis

Total Population Values are in the ‘POP100’ Field Housing Units are in the ‘HU100’ Field Once Joined, you can:  Create a Population (or Housing Unit) Map  Calculate Statistics (i.e. Total Pop for the County), etc.

What Hazards do we have in our Community? B: PROFILE the HAZARDS  Flood (Riverine/Inland)  Hurricane Storm Surge (Coastal)  [Others]

SLOSH: Storm Surge Display Program (NOAA) Register & Download the free Software: (Storm Surge Data comes bundled)

SLOSH: Storm Surge Display Program (NOAA) …Or, Download Storm Surge Data separately from Web Site Explanation of MEOW and MOM Storm Surge Data

SLOSH: Storm Surge Display Program (NOAA) Texas Storm Basins …Download Storm Surge Data separately from Web Site

SLOSH: Storm Surge Display Program (NOAA) 1.Set Storm Basin 2.Select Storm a.MEOW Category Specifics (Direction, Tide, etc.) b.MOM Category

SLOSH: Storm Surge Display Program (NOAA)  ‘sub’ Selected displays Flood Depths (Height of Water above Ground Elevation) at that “point” If Selected, Download includes both Flood Depths and Flood Surface Elevations  ‘sub’ NOT Selected: Displays Flood Elevations Not Selected, Download only includes Flood Elevations Flood Elevations or Flood Depths?

Preparing SLOSH Storm Surge Outputs for GIS ‘Exposure’ Analysis  Define Coordinate System Only if you’re using Software version (See Web-Download version for Properties > Coordinate System)  (a) Re-Project Coordinate System Ex. Texas State Plane, S. Central; Feet, NAD83 Datum Transformation: NAD27 to NAD83  (b) Eliminate “Dry Areas” (Values of “99.9”) Select by Attributes > Export OPTIONAL: Create Thematic Map of Flood Depths  (c1) OPTIONAL: Clip and/or Dissolve so map is cleaner  (c2) OPTIONAL: Create Flood Depth Map

 (b) Eliminate “Dry Areas” (Values of “99.9”) from Data Select by Attributes > Export  (c1) OPTIONAL: Clip and/or Dissolve so map is cleaner  (c2) OPTIONAL: Create Flood Depth Map Preparing SLOSH Storm Surge Outputs for GIS ‘Exposure’ Analysis

Final Storm Surge Map in GIS  (c1) OPTIONAL: Clip and/or Dissolve so map is cleaner Example: Cat 3 (Worst Case)

Final Storm Surge Map in GIS: Flood Depths  (c2) OPTIONAL: Create Flood Depth Map Example: Cat 3 (Worst Case)

What assets do we have in hazard areas? A+B = C: ASSESS the VULNERABILITY (of your Inventory to the Hazards)  Exposure Analysis  Loss Estimation Analysis A: Inventory = Population B: Hazard = SLOSH Storm Surge A+B = C: Assessment = Exposure Analysis How many People are (exposed) in each Storm Surge Category? How many People are (exposed) in each accumulated Storm Surge Category? More specifically

GIS Function: Spatial Query (Select by Location)

How many People are in Storm Surge Category 1? Answer: 30,692 How many People are in each accumulated Storm Surge Category? Answer: (See Next Slide)

Storm Category IndividualCumulative MOMs Cat 130,692 Cat 215,35546,047 Cat 330,97877,025 Cat 415,26492,289 Cat 524,483116,772 How many People are in each accumulated Storm Surge Category? Answer: (See Below)

Of the assets in hazard areas, what might be the impact? A+B = C: ASSESS the VULNERABILITY (of your Inventory to the Hazards)  Exposure Analysis  Loss Estimation Analysis IMPORTANT: Currently, HAZUS does not model the Hurricane Storm Surge hazard However, this will be in the next software release very soon! See Preview Slides!

HAZUS-MH: Loss Estimation Analysis Software (FEMA)

NOAA’s SLOSH Storm Surge Model Selected for Use in HAZUS  SLOSH produces reasonably accurate estimates of surge and runs quickly  Emergency management community is familiar with and comfortable with SLOSH  SLOSH does not include waves or tide Waves to be modeled in Hazus using SWAN Tide treated as a fixed increase or decrease in initial water level based on predicted tide at time of landfall in the absence of storm surge and waves

HAZUS-MH: Storm Surge Model W/ Waves = SLOSH + SWAN No Waves = SLOSH ONLY Hazard Types:  Hurricane Wind Only  Storm Surge Flooding Only  Hurricane Wind + Storm Surge Flooding NAVD Tide treated separately as a single input

HAZUS-MH: Storm Surge Model: Results > Map

HAZUS-MH: Storm Surge Model: Results > Table

HAZUS-MH: Storm Surge Model: Results > Report

Thank You! Questions? Craig Eissler