High Resolution Flash Flood Potential IndexHigh Resolution Flash Flood Potential Indexforfor

Customers and PartnersCustomers and Partners

Jim BrewsterJim Brewster

WFO Binghamton, NYWFO Binghamton, NY

Moneypenny Creek Flash Flood – May Moneypenny Creek Flash Flood – May 20042004

BackgroundBackground Flooding is WFO Binghamton’s Flooding is WFO Binghamton’s

#1 High Impact Hazard #1 High Impact Hazard Central NY and Northeast PA Central NY and Northeast PA

have highly variable geography, have highly variable geography, land cover and use.land cover and use. Steep, rocky terrain along with flatter Steep, rocky terrain along with flatter

sandy plainssandy plains Areas of urbanizationAreas of urbanization Wide range of forest coverWide range of forest cover Similar soil typesSimilar soil types

Experienced forecasters realized Experienced forecasters realized that some areas are more prone that some areas are more prone to flash flooding than others.to flash flooding than others.

But, Where and to what extent? But, Where and to what extent?

Flash Flood Potential Index (FFPI)Flash Flood Potential Index (FFPI)

Developed by hydrologist Greg Smith, CBRFC Developed by hydrologist Greg Smith, CBRFC (2003).(2003).

Geographical features play a key role in flash Geographical features play a key role in flash flooding flooding

Developed as background information to be Developed as background information to be incorporated into production of better gridded incorporated into production of better gridded Flash Flood GuidanceFlash Flood Guidance

Using the FFPI, the roles of land, vegetation and Using the FFPI, the roles of land, vegetation and urbanization in flash flooding are visualizedurbanization in flash flooding are visualized

““Guesswork” to the flash flood problem is Guesswork” to the flash flood problem is reducedreduced

Methodology for creating Methodology for creating FFPIFFPI

Collected available geographic data setsCollected available geographic data sets Used GIS technology to resample, project Used GIS technology to resample, project

and index the data into to a common and index the data into to a common valuevalue

Mathematically develop a new Mathematically develop a new geographic index grid…the FFPIgeographic index grid…the FFPI

The DataThe Data Four geographic data sets :Four geographic data sets :

Slope derived from the USGS DEM Slope derived from the USGS DEM (Digital Elevation Model)(Digital Elevation Model)

MLRC Land Use/Land Cover GridMLRC Land Use/Land Cover Grid AVHRR Forest Density GridAVHRR Forest Density Grid STATSGO Soil Type ClassificationSTATSGO Soil Type Classification

Methodology ReviewMethodology Review

Weight average the geographic layers.Weight average the geographic layers. FFPI = (1.5*Slope + LC + Soils + Forest)/NFFPI = (1.5*Slope + LC + Soils + Forest)/N

Local adjustment to calculationLocal adjustment to calculation Reviewed against historical events Reviewed against historical events Flash flooding occurs in our forested areas.Flash flooding occurs in our forested areas. Is that element really much of an influence here?Is that element really much of an influence here?

FFPI = (FFPI = (1.51.5*Slope + LC + Soils + *Slope + LC + Soils + 0.50.5*Forest)/N*Forest)/N Raw grid is then averaged to individual basins.Raw grid is then averaged to individual basins.

90 Meter Resolution90 Meter Resolution Warm colors = High PotentialWarm colors = High Potential Cool colors = Low PotentialCool colors = Low Potential

FFPI mapped to FFMP BasinsFFPI mapped to FFMP Basins Fit our historical Fit our historical

events events New realizations, New realizations,

especially the low especially the low FF potential areas.FF potential areas.

Differentiates the Differentiates the “best of the “best of the worst” basins in worst” basins in an area generally an area generally known for high known for high flash flood flash flood potential.potential.

FFPI VersatilityFFPI Versatility

Exportable to other platforms

KML/KMZ

GeoTiffGoogle Earth

ESRI shape file

Exportable to other platforms

KML/KMZ

GeoTiffGoogle Earth

ESRI shape file

High Resolution in ActionHigh Resolution in ActionNovember 16, 2006

Flash Flooding & Mud slides

Fatal Gorge FloodFatal Gorge Flood

Storm Total PrecipitationStorm Total Precipitation

90 m - High Resolution90 m - High Resolution

Use of high resolution FFPI in a GIS environment can benefit emergency managers, planning boards, town highwaydepartments, and other local officials and groups.

Glen Brook Fatalities

SummarySummary The FFPI was developed in Binghamton due to the The FFPI was developed in Binghamton due to the

important need to have a static geophysical important need to have a static geophysical reference grid which better illustrates how local reference grid which better illustrates how local earth system features contribute to flash flooding. earth system features contribute to flash flooding.

The FFPI is best used in flood operations when The FFPI is best used in flood operations when mapped to our AWIPS FFMP basins for comparison mapped to our AWIPS FFMP basins for comparison with other flash flood tools and techniques. with other flash flood tools and techniques.

Through GIS technology, the index can be Through GIS technology, the index can be exported to many formats for use by other exported to many formats for use by other government agencies, customers and partners for government agencies, customers and partners for planning and mitigation.planning and mitigation. Please send requests for GIS FFPI layers to Please send requests for GIS FFPI layers to

james.brewster@noaa.govjames.brewster@noaa.gov