Hazard Assessment with GIS Initial Explorations of Hazus MH and Local Data For TJPDC By David L. Phillips With Nicole Gilkeson Leigh Rosen Lory Pendergraph

Planning with Disaster in Mind An applied GIS course Cooperatively with staff of Thomas Jefferson Planning District Commission—A multi-county ecologically diverse region 2.5 months effort

Aims Help Identify and Map Region’s exposure to natural hazards as indicated by National sources. Construct website to document and raise public awareness of hazards in region Assess Inventory of Critical Facilities as provided by HAZUS Assess the usability of HAZUS-MH for a multi-county region Assess the availability of local data

Aims Help Identify and Map Region’s exposure to natural hazards as indicated by National sources. Construct website to document and raise public awareness of hazards in region Assess Inventory of Critical Facilities as provided by HAZUS Assess the usability of HAZUS-MH for a multi-county region Assess the availability of local data

Probability of a Hurricane Hurricanes Probability of a Hurricane The TJPDC area has a less than 2 percent probability of experiencing a hurricane during hurricane season.

Earthquakes 1996 Data

Wildfire According to the Virginia Department of Forestry a large portion of the TJPDC has a high risk of wildfire, shown here in red.

Dam Failure The TJPDC has a total of 12 dams, 6 of which are considered a high hazard risk.

Floods 100-year floodplains indicate 1% chance of flooding each year.

Floods

Hazus-MH Multi-hazard Impact Simulation Models Hurricane Flood Earthquake Each model estimates impacts for region Our experimentation allowed some rough assessments

Modeling Impacts Modeling Natural Hazard Direct Physical Damage Induced Damage Direct Economic Losses Indirect Economic losses

HAZUS_MH Hazard Impact Assessment: Levels of Refinement and Sophistication Modifies cost and damage parameters to local conditions Uses locally acquired data about buildings, population, terrain and natural features. Uses widely available but generalized data

HAZUS-MH Critical Facilities An very good set of the types of facilities considered important from a national perspective: Hospitals, fire stations, police stations, schools, churches, transportation facilities, etc. Systematic consistency across the jurisdictions

HAZUS-MH Critical Facilities Listings found to be incomplete and sometimes inaccurate: Recent facilities missing (Schools, hospitals) Wrong addresses or reported to be located at “headquarters” address. Occasional Incorrect Location

HAZUS-MH Building Inventory Undercounts the number of business locations for some sectors Agricultural Religious

HAZUS-MH Hazus – MH building inventory: Estimates 72,870 buildings in TJPDC 72,000 residential 715 commercial 32 governmental/educational 74 industrial 33 religious County building planimetrics give 149,870 buildings. Many of these are out-buildings.

Using HAZUS Impact Model Multiple scenarios gave local planners “a feel” for the magnitudes of impacts for different intensities and different hazards

Using HAZUS Impact Model TJPDC is “on the fringe” of HAZUS-MH model validity Earthquake damage over estimated at lower (5.0 and below) intensities. Hurricane model “stops” when storm degrades to tropical storm.

Using HAZUS Impact Model TJPDC is “on the fringe” of HAZUS-MH model validity (continued) Flood model designed for detailed study of small or modest “reaches” not regional watersheds. Flood model focuses more on inundation and less on velocity impacts.

Using Local Data Local planimetric data on building footprints allowed: Focused location of buildings rather than Hazus Census Tract or Census Block level aggregates. Local floodplain maps used in conjunction with building footprints identified “Critical Reaches”

Direct GIS measurement of flood exposure

Testing Historic Events Hazus contains some historic events Hurricanes: 1949, Fran, Hazel These are run against current inventory of population, buildings and critical facilities—likely to over estimate historic event impacts. We were able to get a digital data set of 1949-1950 building stock for two jurisdictions. This will allow some “scaling” of model impacts to test the model against historic reporting of damage.

Using even rough results Local planning taskforce beginning to: Assess the likelihoods of different hazards Assess the magnitudes of the impacts of different hazards

Discussion of the Assignment of Likelihoods

Discussion of the Assessment of Severity of Impacts

Using Local Data To Validate HAZUS Data Map HAZUS Critical Facility Data On Local Detailed Maps Use local experts to identify errors or omissions

Charlottesville Floodplain Insert

Charlottesville Floodplain Insert With Identified Data Problems Fire station Miss-located Charlottesville Floodplain Insert With Identified Data Problems County Police Station Missing Flood Plain may need study New Hospital Missing Montecello not listed as Significant Cultural Facility Montecello High School Missing

Hazard Assessment with GIS