To learn more about USGS’ role providing science to decision makers before, during and after Hurricane Harvey, visit the USGS Hurricane Harvey page at https://www.usgs.gov/harvey.
Landsat Images Before and After Harvey Illustrate Flooding in Texas
The U.S. Geological Survey has released new Landsat satellite images that show some of the flooding and coastal change Hurricane Harvey’s historic rains and storm surge produced across much of eastern Texas.
Harvey’s deluge set a number of records in Texas streams and rivers during the peak period of flooding with 40 streamgages measuring record highs and more than 80 streamgages recording water levels at or above flood stage – the point at which water can start overflowing banks – on 21 rivers, streams and bayous, with preliminary reports showing some rivers have already crested reaching their highest levels.
Among the many waterways in southeastern Texas that exceeded flood stage was the Brazos River, which flows west of Houston into the Gulf of Mexico. A USGS streamgage on the Brazos near Rosharon showed that a river level normally at around 10 feet peaked to 52.65 feet, almost 10 feet above flood stage, on August 29.
Even with scattered clouds in the images, the extent of flooding on the landscape just south of Houston is evident. The Landsat 8 image from August 12 shows the area before the storm hit while Landsat 7 passed over the same area on September 5 to show the flooded Brazos River.
The hurricane’s eye made landfall in Rockport, Texas, and this before and after Landsat image clearly shows shoreline retreat on barrier islands caused by Harvey’s storm surge. Landsat 8 captured the before image August 19, 2017 and Landsat 7 acquired the after image on September 12 with changes to the coastline still visible 18 days after the storm hit.
Corpus Christi and surrounding communities did not experience the extreme rainfall Houston and other nearby regions received, however, winds gusting to 130 miles per hour were the main source of business and residential damage in the Corpus Christi area.
Landsat is a joint effort of both USGS – ran by the Earth Resources Observation and Science Center – and NASA. USGS conducts Landsat operations and NASA develops and launches new satellites that meet science requirements. In addition to imagery of natural hazard events, Landsat provides valuable data for land use research.
The before and after Landsat images can be seen by visiting https://eros.usgs.gov/hurricane-harvey-flooding or https://eros.usgs.gov/shoreline-retreat-near-corpus-christi-texas.
View current monitoring data for almost 800 USGS real-time stream, lake, reservoir, precipitation and groundwater stations in Texas in context with current weather and hazard conditions at USGS Texas Water Dashboard. Two fully-autonomous Twitter feeds distribute water level and precipitation data during flooding or severe rainfall: @USGS_TexasFlood and @USGS_TexasRain.