texas height modernization dr. gary jeffress, rpls texas spatial reference center national height...

Texas Height Modernization

Dr. Gary Jeffress, RPLSTexas Spatial Reference Center

National Height Modernization Partner MeetingNOAA Gulf of Mexico Disaster Response Center

Mobile, Alabama – April 2014

Recent Projects

• 2012-2013 GPS Precise Network Observations Along the Texas Gulf Coast– TCOON Tide gauge Benchmarks– Historic USACE tidal benchmarks– Texas CORS– GPS-able NGS first & second order Benchmarks

• A total of 72 network sessions and 153 stations observed (Adjust and Pages)

• All stations Bluebooked• Funded by US Army Corps of Engineers

2012-2013 GPS Precise Network Observations Along the Texas Gulf Coast

2013-2014 GPS Precise Network ObservationsAlong the Florida Gulf Coast

CORS on Tide Gauges Florida

Pensacola, FL

CORS on Tide Gauges Florida

Fernandina, FL

CORS on Tide Gauges Florida

St. Petersburg, FL

CORS on Tide Gauges Florida

Cedar Key, FL

CORS on Tide Gauges TexasExisting CORS 4

(USACE 2,NERRS 1,USFW 1)Proposed

Sentinel CORS 4(USFW)

Proposed Height Mod.

CORS 5TOTAL 13

Sentinel

The need for accurate Elevation in Texas

Austin, 1991Houston, 2001

Lives are lost and $Billions of property are lost.

National Flood Statistics (2001)From http://floodsafety.com/national/life/statistics.htm

Licensed Surveyor’s Role

13Up to 80% of these benchmarks have disappeared

Answer: The data are old and subject to change and destruction.

Why are Elevations so bad?

Why are Elevations Important?An Example from Galveston Bay, Texas

An Example from Galveston Bay, TexasFrom Google Street View

An Example from Galveston Bay, Texas

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From Google Maps

An Example from Galveston Bay, Texas

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An Example from Galveston Bay, Texas

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An Example from Galveston Bay, Texas

An Example from Galveston Bay, Texas

FF = Finished Floor LevelFF = 13.86 feet

FIRM September 1999Zone AE EL 12 = 12.00 feet

FIRM September 2012Zone AE EL 15 = 15.00 feet

An Example from Galveston Bay, Texas

Surveyor’s Elevation Datum

Flood Insurance Quote

For Sale $1,028,697 ?

Thank you for listening.gary.jeffress@tamucc.edu