July 10, 2020. (Click image for high resolution view.)
Despite a dry July, many farmers in Iowa expected a good harvest in the fall. Instead, many had their fields of corn and soybeans flattened by strong winds of hurricane.
On August 10, 2020, an unusually strong and long-lasting line of thunderstorms – a derecho – struck large areas of Iowa and the American Midwest. More than a week after the storm, tens of thousands of Iowans were still without electricity, and many farmers mumbled whether they could save crops and repair grain silos for the coming harvest.
The Operational Land Imager (OLI) on Landsat 8 took a picture of storm-damaged fields around Marshalltown, Iowa the day after the storm. For comparison, the second image shows the same area on July 10, 2020. Wind-damaged crops appear light green. Dark areas within the damage wall can be tree breaks as fields where crops took less damage.
August 11, 2020. (Click image for high resolution view.)
While large hailstones can quickly steal stalks and crush corn and soybean plants – leaving dark brown streaks across rural landscapes – much of the damage in August 2020 was caused by strong winds blowing stalks that were already heavy with riding corn dogs , explained Christopher Schultz, a NASA Marshall Space Flight Center meteorologist. However, the damage was not exclusively caused by wind. In some areas, small hailstones and leaves are shed.
It is possible that some of the clover plants still have intact roots and will continue to grow in the coming weeks; others could be used for silage or for other purposes. But many experts expect heavy losses and major challenges for harvesting and storing all that remains. As damage estimates evolve, agricultural economists project that the storm is likely to cause nearly $ 4 billion in damage, making it one of the most costly thunderstorms on NOAA’s weather and climate disaster tracker for the past decade.
“This is by no means the first time the Midwest has seen heavy thunderstorms damage to crops, but the magnitude of the damage here is really out there,” said Jordan Bell, another NASA Marshall researcher who described the incident. follows. ‘We’re talking about a tornado that is a sequence of larger than other tornadoes than thunderstorms we’ve seen in the past. This is an event that people will remember for a long time. A broader view of the damage of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor is available here.
Schultz and Bell are part of a NASA Earth Applied Sciences project that aims to develop climatologies of hail events in North America and around the world. Such data would help insurance companies and other stakeholders to assess the risk of crop loss due to severe thunderstorms.
“We use full-suite sensors to detect storms and assess the damage they cause,” said Kristopher Bedka, the project leader. “And we do it not just for this event, but for catastrophic events around the world, so we can learn how to best quantify damage in an automated way.”
Images from NASA’s Earth Observatory by Joshua Stevens, using Landsat data from the US Geological Survey.
