KENTUCKY HAZARD MITIGATION PLAN RISK ASSESSMENT

Transcription

1 KENTUCKY HAZARD MITIGATION PLAN RISK ASSESSMENT

2 Presentation Outline Development of the 2013 State Hazard Mitigation Plan Risk Assessment Determining risk assessment scale Census Data Aggregation Levels State Wide Grid Dasymetric Mapping Risk Assessment Methodology Exposure Hazard Vulnerability How can your community use the plan maps Exposure Maps Hazard Maps Vulnerability Maps

3 Census Data Aggregation Levels Aggregation Levels Country State County Tract Block Group Block Tracts, Block Groups, and Blocks are aggregation levels that are designed to be similar in population but not area.

4 Census Tracts Census Tracts are a statistical subdivision of a county Tracts are designed to have between 1,500 and 8,000 persons Tracts can change from Census to Census as the population changes. In Kentucky Counties have between 1 tract and 191 tracts in the 2010 Census

5 Census Block Groups Census Block Groups are a statistical subdivision of Census Tracts Block Groups are designed to have between 600 and 3,000 people with an optimum size of 1,500 Block Groups can change from Census to Census Block Groups are the smallest level which the Census bureau publishes sample data (American Communities Survey or ACS) As of the 2010 Census all data excluding population count, sex, age, race, or ownership status is sample data.

6 Census Blocks Census Blocks are a statistical subdivision of Block Groups Blocks in urban areas are often literally a city block, in rural areas blocks can be much larger In KY Blocks range from to less than.001 square kilometers. Blocks are the smallest subdivision that the Census releases full count data on.

7

8

9

10 Military Grid Reference System MGRS provides an alternative aggregation level to the Census Block level Each unit is identical in size Allows better comparisons between units in different parts of the state Population and demographic data is not calculated at MGRS level Assign proportionally based on area Assign using Dasymetric mapping based on area

11 Grid Advantages For Risk Mapping Equal area calculations based on each unit being equal sized Allows better comparisons between planning areas in different parts of the State Potential for better policy decisions and dollar allocation Improved visual interpretations Enhanced tools for local planning usage Military grid provides enhanced usage during response and recovery

12

13 Dasymetric Mapping Method of mapping population within an aggregation area using population data and land cover data Plan used the urban 3 class method (shown in right most picture).

14 USGS Dasymetric Mapping Tool A free tool which simplifies the Dasymetric process Requires Land Cover data to be broken down into 4 Classes User defined breaks Suggests High Density Low Density Non-Urban Inhabited Uninhabited

15 USGS Dasymetric Tool Key functions Empirical Sampling Empirical sampling is used to determine the fraction of the census unit's population that should be allocated to each inhabited class for the study area Areal Weighting The population density fraction must be adjusted by the percentage of the block-group s total area that each inhabited class occupies. A ratio is calculated for each inhabited class representing the percentage of area that an inhabited class actually occupies within a block group to the expected percentage. The area ratio is used to adjust the population density fraction accounting for the variation of both the population density and area for the different inhabited classes for each block group. Source:

16

17

18 Land Cover Data Issues Low Resolution In non urban areas, there may not be a differentiation in land class between a residence and the surroundings Resolution is typically able to differentiate roads from surroundings in rural areas Assumption is population typically lives near roads Developed Areas that are uninhabited can show as high density development Use Feature Classes to reclassify raster areas to eliminate developed areas that are uninhabited Highways Airports Parks Block level data often finite enough that industrial areas are separated from residential areas and show no population

19

20

21

22

23

24

25

26 2013 Kentucky Risk Assessment Important definitions associated with this vulnerability assessment model: Exposure: A community s assets: people, property, essential facilities, and infrastructure potentially exposed to a hazard Hazard: Anything which either threatens the residents of a community or the things that they value Vulnerability: What part of an exposure is at risk to each hazard

27 Risk Model Simplified Hazard Vulnerability Score = Exposure Score + Hazard Score Exposure Score = Population Score + Property Score + Critical Infrastructure Score Hazard Score can generally be expressed as: Hazard Score= % Area Affected Score + Loss Score

28 General Scoring Methodology Data Aggregated to the Grid level Spatial point and line data that is not smoothed over an area is transformed using the Natural Log +1 (LN+1). This was done to reduce the effect of outliers on the overall score while maintaining its place in the order. Then Data scored from 0-1 to provide the variables score. Image from:

29 Exposure Made up of 3 categories each accounts for 1/3 of the score Population Score Property Score Critical Infrastructure Score

30 Population Score Population Score is comprised of one variable 2010 Census block population Assigned using Dasymetric mapping Used 2010 Census Data 2006 Land Cover Data

31

32 Property Score Property Score is comprised of two variables 2010 Census Block Group Total Household value Each Grid was assigned household value based on that grids percent area of the block group. Business points from ESRI Business Analyst Number of business s were counted for each grid The effect of outlier grids was reduced using the natural log method and scored Each variable accounted for 50% of the property Score

33

34 Critical Facility Score Critical Facility Score is comprised of two aggregate groupings Critical Facility Point Data fire stations, police stations, prisons, primary schools, hospitals, emergency operation facilities, nursing homes, public health facilities, emergency medical service facilities, sewer treatment facilities, sewer package treatment and lift station facilities, water pumps, water treatment plants, sewage treatment plants, water tanks, electric power plants, pressure and storage gas facilities, refinery and storage oil facilities, airport facilities, HWY bridges, rail facilities, EPA FRS Facilities, and State owned facilities. Point data accounted for 80% of the score and the LN+1 was used Critical Facility Line Data sewer lines, water lines, power transmission lines, pipelines, KYTC all roads mapped, and railroads. Line data accounted for 20% of the score and the LN+1 was used

35

36

37

38 2013 Hazard Groupings 2010 Hazards 2013 Hazards KYEM Hazard Category Dam Failure Dam Failure Human-Made Drought Drought Severe Weather Earthquake Earthquake Geologic/Earthquake Extreme Heat Extreme Temperature Severe Weather Flood Flood Flood Hail Hail storm Severe Weather Karst/Sinkhole Karst/Sinkhole Geologic/Earthquake Mine Subsidence Mine/Land Subsidence Geologic/Earthquake Landslide Landslide Geologic/Earthquake Severe Storm Severe Storm Severe Weather Severe Winter Storm Severe Winter Storm Severe Weather Tornado Tornado Severe Weather Wildfire Forest fire Natural Hazards (Non-Severe Weather)

39 Hazard Score Hazard Score is typically comprised of two scores. % Area Affected Score This score is the percent of the grid in a mapped area of risk Loss Score This score is a count of the number of events.

40 Hazard Score Inputs 2013 Hazards % Area Score Loss Score Dam Failure Dam Inundation Zones Dam Hazard Classification Score Drought Earthquake Extreme Temperature Palmer Drought Severity Index Score USGS 2% Chance in 50 Years modified with NEHERP soil amplification data. Grid level score of county level extreme temperature events Flood FEMA Floodplain SRL and RL properties Hail storm NEXRAD Level-III hail radar points within 25 miles Karst/Sinkhole Mapped karst areas Sinkholes Mine/Land Subsidence KGS mined out areas AML mine subsidence areas Landslide USGS landslide map KGS landslide points Severe Storm Severe Winter Storm Tornado NWS wind point and wind swath events within 25 miles Grid level score of county level winter storm events NWS tornado paths within 25 miles Forest fire USGS NLCD forested areas greater than 3 acres KDF forest fire point layer

41 Hazard Score Example- Flooding Flood Hazard Score is comprised of two scores Percent area score Percent of each grid that is in a Mapped FEMA Floodplain (DFIRM) Loss Score Combination score of Repetitive Loss and Severe Repetitive Loss properties

42

43

44 Hazard Score Example- Tornado Tornado Hazard Score is comprised of one score Tornado Loss Score Tornado Loss Score is a count of the number of tornadoes within 25 miles of each grid.

45

46

47 Maps for Each Hazard Exposure Score shows what is at risk to a hazard (assets) Identify areas where if an event happened the impact would be greatest due to increased assets Hazard Score shows where the risk to a hazard is Use to help plan the future growth of your community, direct growth out of high hazard areas Vulnerability Score shows where the Exposure and Hazard intersect Use to identify areas for mitigation, help prioritize and identify areas of mitigation interest: Emergency Management

48 Contacts Josh Human Director Center for Hazards Research and Policy Development Ben Anderson Project Manager Center for Hazards Research and Policy Development