risk map early demonstration project lackawanna county, pa cco meeting september 13, 2011
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Risk MAP Vison
Through collaboration with State, Local, and Tribal entities, Risk MAP will deliver quality data that increases public awareness and leads to action that reduces risk to life and property.
Early Demo Project Scope
Develop Risk MAP ProductsChanges Since Last FIRMMulti Frequency Raster Flood Datasets
3D Flood Elevation Flood Depth
Risk Communication Datasets % Annual Chance Layer Probability of Flooding in 30 years Layer
Areas for Potential Mitigation
Early Demo Project Scope
Develop Risk MAP ProductsRisk Assessment Analysis
Using FEMA’s HAZUS SoftwareFlood Risk DatabaseFlood Risk ReportFlood Risk Map
Changes Since Last FIRM-CSLF-
What is it? GIS layer depicting the
changes in SFHA and Floodway since previous mapped FIRM
Quantifies Land Area Zone Changes Contributing Engineering
Factors (Why?)
Uses: Communication and Outreach Public Notification through
Mailings Internet Outreach Applications
Changes Since Last FIRM-CSLF-
Early Demo Results SFHA Changes
Total Area: 18 sq. miles Increase: 6.35 sq. miles Decrease: -9.85 sq. miles Net Change: -3.52 sq. miles
Floodway Changes Total Area: 2.57 sq. miles Increase: 2.35 sq. miles Decrease: 0.0 sq. miles Net Change: 2.35 sq. miles
Water Surface GridsMultiple Return Periods
What is it? GIS datasets showing 3D flood
elevations every 20 feet throughout the floodplain.
Developed using results from computer modeling and is basis for flood depth grids.
Developed for multiple flooding events (10%, 2%, 1%, 0.2%) countywide, where applicable.
AE and A Zones
Uses: Hazard Communication and
Outreach Efficient BFE Determination Could be paired with building
specific data (FFE, values, etc.) for loss estimations
Depth GridsMultiple Return Periods
What is it? GIS datasets showing flood
depths every 20 feet throughout the floodplain.
Developed by subtracting 3D flood layer from ground surface.
Developed for multiple flooding events (10%, 2%, 1%, 0.2%) countywide, where applicable.
AE and A Zones
Uses: Hazard Communication and
Outreach Loss Estimation Using FEMA’s
HAZUS software.
Velocity GridsMultiple Return Periods
What is it? GIS datasets showing average
flow velocities throughout the floodplain.
Developed for new detail study only.
Developed for multiple flooding events (10%, 2%, 1%, 0.2%) countywide, where applicable.
Uses: Hazard Communication and
Outreach Risk Assessment. Combined with Depth
Information for damage potential.
Percent Annual Chance Grid
What is it? GIS layer showing the
“threshold” flood that inundates a given land area (ex. 75-year flood)
Also known as the “Percent Annual Chance Grid”
Uses: Hazard Probability
Communication Efficient / real-time flood
mapping of non-standard flood events.
Used as basis of developing the percent 30-year grid.
Percent Chance of Flooding in 30 Years Grid
What Is it? Estimates the probability of
flooding at least once during a 30 year period
Developed using the percent annual chance grids
Uses: Probability Communication Goes beyond the
traditional “in or out”phylosophy
HAZUS Loss Estimations
• Flood Losses (per census block) Computed using Census Data and multi-return depth grids
• Separate scenarios created for each return period
Areas of Mitigation Interest-AOMI-
• Dataset which identify areas where mitigation efforts could be potentially effective
• Locations were determined from the effective FIS as well as the local Hazard Mitigation Plan