Overall Hazard Risk Score
Overall Hazard Risk ScoreThe Risk Score is the Average of the Individual Hazard Risk Score of the Hazards Selected. |
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Very Low
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Low
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Medium
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High
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Very High
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1 | 2 | 3 | 4 | 5 |
Factors | Score |
This index consolidates information from key indicators of changes in precipitation and developed area. These changes will affect the volume of stormwater runoff and can be used to determine risk to future flood events. We used estimates for changes in 100-year rainfall of 1 hr duration from the National Oceanic and Atmospheric Administration (NOAA) and average change in percent impervious surface from 2001 to 2019 aggregated to HUC 8 watersheds from the National Land Cover Database (NLCD) to calculate index values.
This index consolidates information from indicators of past flood risk and losses incurred from previous flooding events. We used data for total payout for the National Flood Insurance Program (NFIP) flood claims and total count of NFIP policies by census tract to calculate index values.
This index consolidates information from indicators of current flood risk. We use probability of occurrence of a damaging flood event from the Institute for a Disaster Resilient Texas (IDRT), flood zones from the Texas Water Development Board (TWDB) Floodplain Quilt geodatabase, and storm surge category data from NOAA to calculate index values.
This index consolidates information from indicators of fire risk. To capture the overall level of fire risk, we used the annual probability of wildfire burning in a specific location, probability of seeing flames that are more than 4 feet, change in Wildland Urban Interface and Intermix (the zone of transition between developed to adjacent natural areas) from 2010 to 2020 from the US Forest Service (USFS), and the sum of acres burned in wildfire events that occurred from 2000-2022 from the National Interagency Fire Center (NIFC) to calculate index values.
The county level hazard indices were calculated by averaging the ranked values of selected indicators. Ranking for these indicators was done at county level. To report the final value for each index the average of ranked indicators was recoded based on the following scale:
Website for more Information:
https://www3.epa.gov/region1/airquality/pdfs
Website for more Information:
https://www.ready.gov/hazardous-materials-incidents
Website for more Information:
https://www.edf.org/blog/2013/04/10/7-tips-protecting-yourself-against-ozone
All datasets for creating the Risk indices have been acquired from best available non-proprietary data sources available. Please refer to the table below for the more information about each data source.
All risks are scored on a relative scale of 1-5: That is, a parcel with a score of 5 is estimated to be at five times more risk from the specific hazard than a parcel with a risk score of 1 for the same hazard. A risk score of 0 implies absence of any known threat from the specific hazard to the selected parcel.
Overall score is the mean of all the specific hazard risk scores available for the the selected parcel.
Risk | Scoring Description |
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Hurricanes |
Indicator: Hurricane Risk Zones, presented on a relative scale of 1-5.
Description: This layer is derived from the Texas A and M / DEM Risk Area maps. Risk area zones (1 - 5 ) are identified by hurricane categories. Area 1 corresponds to a Category 1 Hurricane. |
Floods |
Indicator: Risk of flooding, presented on a relative scale of 1-5.
Description: Parcels within the 100 year floodplain are scored the highest (5), parcels within 500 year floodplain are considered to be at medium risk (3). |
Flood Claim Score |
Indicator: Parcels within block groups rated on flooding frequency.
Description: Parcels with a score of 1, are located within a block group without any paid claims since 2000. Scores between 1 and 2 indicate the property is located in an area with a relatively low frequency of flooding. A parcel with a score of 2-3 is located in an area that experiences moderate flooding. A score between 4-5 can be interpreted as being a parcel located within group with high amount of flooding. Any parcel with a score of 5 would be within a block group that experiences a very high amount of flooding. This scale offers insight into the frequency at which parcels within a block group are flooded, regardless of whether they are located within a flood zone. |
Wildfire |
Indicator: Potential risk of wildland fires burning flammable structures, presented on a relative scale of 1-5.
Description: The map was developed from mapping done by the Rocky Mountain Fire Sciences Lab for the entire United States. Data for Texas was extracted from a raster grid and converted to shapefile format. The end map was an integration of 3 GIS data layers: housing density, potential fire exposure, and extreme weather potential. |
Traffic |
Indicator: The count of vehicles per day within 500 meters of the census block centroid in which the selected parcel is located, divided by distance in meters, weighted by average block population, presented on a relative scale of 1-5.
Description: This measure of traffic proximity is based on average annual daily traffic (AADT) estimates in the Highway Performance Monitoring System (HPMS 2011) dataset in the Department of Transportation (DOT) National Transportation Atlas Database (NTAD). The HPMS highway data is maintained by states and compiled by DOT. |
NPL Sites |
Indicator: Count of proposed and listed NPL sites within a distance of 5km (or the nearest one beyond 5km), each divided by the distance in kms, presented on a relative scale of 1-5.
Description: EPA places sites on the National Priorities List (NPL) (a key subset of all “Superfund” sites) based on a defined set of criteria and a public comment process. Inclusion of a site on the NPL does not impose a financial obligation on EPA, nor does it assign liability to any party. The NPL serves primarily informational purposes, identifying sites that appear to warrant remedial actions, thereby conveying to policymakers and the public the size and nature of the nation’s cleanup challenges. |
RMP Sites |
Indicator: The count of RMP (Risk Management Plan) facilities within 5 km (center of the parcel to the point location of the facility) , divided by distance, presented on a relative scale of 1-5. Absence of any RMP facility is denoted by a score of 0.
Description: RMP facilities are those facilities required by the Clean Air Act (CAA) to file risk management plans. The regulations under CAA section 112(r) establishes a List of Regulated Substances—72 substances listed because of their high acute toxicity and 60 because of their flammable or explosive potential—along with threshold quantities (TQs) for each. The listed substances are those that pose the greatest risk of harm from accidental releases. If a facility maintains a quantity of any such chemical above those TQs, it must file an RMP with EPA. More information is available at: |
TSDF Sites |
Indicator: The count of TSDF (Hazardous waste Treatment, Storage and Disposal facilities) sites within 5 km (center of the parcel to the point location of the facility) , divided by distance, presented on a relative scale of 1-5. Absence of any TSDF facility is denoted by a score of 0.
Description: The Resource Conservation and Recovery Act (RCRA) was further amended in 1984 with the addition of the Hazardous and Solid Waste Amendments. RCRA Subtitle C establishes a federal program to manage hazardous wastes from “cradle to grave,” or from generation to disposal, to ensure that hazardous waste is managed in a manner that protects human health and the environment. EPA has developed Subtitle C regulations governing hazardous waste generation, transportation, and the several hundred active treatment, storage or disposal facilities (TSDFs). More information about TSDF is available at: |
Ozone |
Indicator: The May–September 2011 (summer/ ozone season) average of daily-maximum 8-hour-average ozone concentrations, in parts per billion (ppb), presented on a relative scale of 1-5.
Description: Ozone data are estimated by EPA from a combination of monitoring data and Community Multi-scale Air Quality (CMAQ) modeling. The downscaling was done by EPA using fusion model that utilize both air quality monitoring data from NAMS/SLAMS (data collected by EPA, state, local and tribal air pollution control agencies at more than 600 hundred monitors nationwide) and numerical output from the Models-3/CMAQ model. This downscaling approach is designed to provide daily, predictive PM2.5 (daily average) and O3 (daily 8-hour maximum) surfaces for a given year, such as 2011, at specified points. |
Particulate Matter |
Indicator: Annual 2011 average PM2.5 concentration in micrograms per cubic meter (_g/m3), presented on a relative scale of 1-5.
Description: PM2.5 data are estimated by EPA from a combination of monitoring data and Community Multi-scale Air Quality (CMAQ) modeling. The downscaling was done by EPA using fusion model that utilize both air quality monitoring data from NAMS/SLAMS (data collected by EPA, state, local and tribal air pollution control agencies at more than 600 hundred monitors nationwide) and numerical output from the Models-3/CMAQ model. This downscaling approach is designed to provide daily, predictive PM2.5 (daily average) and O3 (daily 8-hour maximum) surfaces for a given year, such as 2011, at specified points. |
Earthquake |
Indicator: Estimated risk from Earthquake based on estimated Earthquake Ground Acceleration, presented on a relative scale of 1-5.
Description: This layer is derived from the USGS. Ground acceleration is measured as a percent of gravity (distance/time). The dataset utilized showed the peak acceleration (% gravity) with 10 % probability of exceedance in 50 years. The lowest is 0-2%, highest is 32+%. |
Subsidence |
Indicator: Risk of Subsidence along the Coastal zone, presented on a relative scale of 1-5.
Description: The dataset was created by Texas Geographic society depicting the occurrence of subsidence along the Texas coastline. The base data utilized to create this indicator shows gradation of subsidence from 1 to 10 feet in 5 groupings |