Detecting Flood Damage to Agricultural Land in Texas Hill Country

NASA Harvest and NASA Acres assess July 4th flooding impacts on croplands and rangelands in Kerr County

In early July, heavy rains caused the Guadalupe River in Kerr County, Texas, to overflow its banks, flooding homes, businesses, and farmland across the region. Now, a new rapid assessment led by NASA Harvest in collaboration with NASA Acres under the RAAPID (Remote-sensing Agricultural Assessments for Policy Impact and Decision-making) Center offers a clearer picture of how agriculture was affected by the floodwaters.

Using a combination of synthetic aperture radar (SAR) and optical satellite imagery, the team mapped inundated areas across the county, differentiating between permanent water bodies and new floodwaters resulting from the storm. The analysis found that, as of the satellite overpass time on July 10th at 7:35pm (local time, CET; 6 days after the main flooding event):

• 676 acres of rangeland were flooded—about 0.36% of the county's total rangeland, and

• 65 acres of cropland were inundated, accounting for over 9% of the county’s total cropland.

The team used Sentinel-1 and HLS satellite data to map flood impacts across rangelands and croplands in Kerr County. Notably, the most recent imagery available was from July 10th, six days after the flooding occurred, meaning the full extent of the damage may be underrepresented, as floodwaters likely receded significantly in the days following the event.

While the absolute area of cropland impacted may seem small, the proportion of affected land is significant given Kerr County’s limited agricultural footprint. In rural economies where farming and ranching play a major role, even short-term flooding can delay planting, reduce yields, damage infrastructure, and strain local livelihoods.

“These types of rapid assessments help communities and decision-makers understand where damage occurred and how severe it was,” said Dr. Mehdi Hosseini, NASA Harvest remote sensing and SAR expert who led the analysis efforts. “It’s critical information for guiding recovery, directing resources, and planning for future resilience.”

The RAAPID Center specializes in using satellite data to respond quickly to agricultural crises caused by natural disasters, market shocks, or conflict. In this case, remote sensing allowed analysts to see through cloud cover and rapidly detect flooded areas, even in relatively small and dispersed pockets.

“When disaster strikes, we often don’t have the time or ability to get boots on the ground right away. Satellite data can provide rapid impact estimations to help us understand what’s happening on the landscape. These estimations enable emergency responders, farmers, and local officials to make informed decisions,” explains Jacob Orser, NASA Acres Program Support Specialist and one of the team members who conducted the Kerr County analysis.

With intensifying frequency and severity of extreme weather events, including heavy rainfall and flash floods, NASA’s agriculture consortia’s efforts to monitor food supply impacts in near real-time are becoming increasingly important. By combining Earth observation with local land use data from USDA and other sources, NASA Harvest and NASA Acres aim to provide reliable, science-based information that supports farmers, communities, and policymakers alike.

As Texas continues to grapple with weather volatility, tools like these will be essential for building a more resilient agricultural future—one where farmers and ranchers aren’t left guessing when the next flood hits and how to deal with the repercussions.