flood map modernization and the tennessee base mapping program

Office for Information Resources

GIS Services

Flood Map Flood Map Modernization and Modernization and the Tennessee Base the Tennessee Base Mapping ProgramMapping Program

Flood Map Flood Map Modernization and Modernization and the Tennessee Base the Tennessee Base Mapping ProgramMapping Program

Dennis Pedersen, Director F&A, OIR – GIS Services

OIR – GIS Services 2

Tennessee Base Mapping Program

• What is the DFIRM Product?• Components of DFIRM Product• Tennessee Base Map Source Data• Tennessee Base Map Topography

Source Data• GIS Data Sources• Benefits of DFIRM Product• Demonstration

Presentation OverviewPresentation OverviewPresentation OverviewPresentation Overview



What is the DFIRM What is the DFIRM Product?Product?

• Official basis for implementing the regulations and requirements of the National Flood Insurance Program (NFIP)

• A digital database that encompasses several features or layers of spatial information

• DFIRM database includes:– Flood hazards areas

• 1% annual chance flood (100-year flood), known as the base flood

• Areas of 0.2% annual chance flood



What is the DFIRM What is the DFIRM Product? (cont.)Product? (cont.)

– Base (1% annual chance) Flood Elevation (BFE) lines with mapped cross section lines

– Structures (dams, bridges, culverts, levees etc.)

– Hydrographic features (streams, lakes, shorelines)

– Transportation features with labels– Political areas (corporate and county

boundaries, National Parks, forests, and military lands)



What is the DFIRM What is the DFIRM Product? (cont.)Product? (cont.)

– Permanent benchmarks with National Geodetic Survey (NGS) Permanent Identifier

– FIRM panel areas with effective date, size, scale, and corner coordinates

– USGS 7.5-minute quadrangle areas– Required to meet FEMA standards and

specifications• Subject to community review and

approval



Components of DFIRMComponents of DFIRM

DFIRM=

Flood DataBase + Topography +



• Vision Statement: Create a statewide GIS base map through partnership development that can be used in support of a wide range of local, state, and federal programs

Base Mapping Program Base Mapping Program Base Mapping Program Base Mapping Program



Tennessee Base Map Tennessee Base Map Source DataSource Data

• Parcels and related features– Parcel boundaries– Parcel annotations– Other cadastral features

• Planimetrics - Edge-of-pavement (EOP)- Hydrology

- Streams- Lakes, rivers, and shorelines



Tennessee Base MapTennessee Base MapSource Data Source Data (cont.)(cont.)

•Street centerlines•Administrative boundaries

–County and city



Tennessee Base Map Tennessee Base Map Topography Source DataTopography Source Data• Two different DTM products: standard and

high accuracy (HA)• Standard DTM vs. High Accuracy DTM

–Standard produces the orthophoto–HA produce 10’ contours for 400’ scale

and 2’ contours for 100’ scale• FEMA subcontractors use DTMs to produce

contours• Modify DFIRM for more accurate depiction

of floodway boundaries



TNBMP – Digital Terrain ModelTNBMP – Digital Terrain Model



Other DFIRM Data Other DFIRM Data SourcesSources

•Local Government– Utilities– Planning – Engineering– GIS departments

•Tennessee Department of Transportation

•Tennessee Valley Authority (TVA) & Corps of Engineers

– Flood Studies– Contours– Anecdotal Information– Structure Elevations



Benefits of DFIRM Benefits of DFIRM ProductProduct

• Increase quality, reliability, and availability of flood data and flood hazard maps

• Provide timely flood hazard information • Enhance ability to manage risks and

issues locally• Provides a comprehensive approach to

economic development, mitigation planning, and emergency response



Benefits of DFIRM Product Benefits of DFIRM Product (cont.)(cont.)• Provide detailed information for builders

and developers for making decisions• Flood risks and Flood hazards are

demonstrated more efficiently for local officials and community planners

• Provide insurance agents, companies, and lending institutions updated flood map information resulting in fair and equitable insurance rates



• How can State agencies create and maintain spatial data once and use (share) it many times?

The “Tennessee Map” (TNMap)

Enterprise GIS DevelopmentEnterprise GIS Development



• Goals– Develop enterprise GIS infrastructure to provide

secure, usable, and easy access to TNBMP data– Provide State agencies with ability to publish data

to enterprise GIS– Support vision of USGS’ National Map and NSDI– Identify data stewards, reduce or eliminate

redundant GIS data collection

The Tennessee Map (TNMap): The Tennessee Map (TNMap): Enterprise GIS ArchitectureEnterprise GIS Architecture



• Geo-portal application• Base Map Data Repository• Shared GIS infrastructure for application

hosting• Access: Public, State GIS users

TNMap…More than just a map

The Tennessee Map (TNMap): The Tennessee Map (TNMap): Enterprise GIS ArchitectureEnterprise GIS Architecture

TNMap portal demonstration…



GIS Data WorkflowGIS Data Workflow

Custom GIS Data=

GIS AnalysisBase Map

Data + Tabular +



State GIS Data State GIS Data

Hazmat / Schools / Hospital locations

Environmental / Conservation features

City / County / Admin. Boundaries (OIR GIS)

Streets / Rivers / Land Features (OIR GIS)

Property Boundaries (OIR GIS)

Imagery / Elevation (OIR GIS)



OIR-GIS/TDOT - PartnershipOIR-GIS/TDOT - Partnership

• TDOT Modernizing Equipment– Digital camera suitable for ortho photo production– Training staff on new photogrammetry production req.– ortho acquisition for ¼ of State annually

• 2008 Acquisition: Region 4 (West TN)

• OIR-GIS responsible for data hosting and distribution– TNMap enterprise GIS– Dissemination to local government



– FEMA Map Service Center:• https://msc.fema.gov/

– FEMA Mapping Information Platform:• https://hazards.fema.gov/

– Administrative Questions:• Stan Harrison, Reg. Director, ECD Local

Planning 423-434-6476

FEMA Flood Map FEMA Flood Map Modernization:Modernization:On-line and other ResourcesOn-line and other Resources

FEMA Flood Map FEMA Flood Map Modernization:Modernization:On-line and other ResourcesOn-line and other Resources



Thank you….Thank you….Thank you….Thank you….

• Contact Information:– Dennis Pedersen, Director, GIS

Services312 8th Avenue North16th Floor, WRS Tennessee TowerNashville, TN 37243-0288

– E-mail: [email protected]– Phone: 615-741-9356

http://tnmap.state.tn.us/portal

http://tnmap.state.tn.us/portal

flood map modernization and the tennessee base mapping program

Documents

base floodareas

statewide gis base map

cityoir gis services

approvaloir gis services

shorelinesoir gis services

military landsoir gis

flood map modernization

contoursmodify dfirm