AUSTIN (KXAN) — One of the worst droughts in recorded history in Texas occurred in 2011, but a new study from scientists at UT Austin published in the Journal of Hydrology shows the drought was even worse than previously thought.
The 2011 drought caused wildfires in parts of the state, including the Bastrop Complex Fire, $7 billion in losses to crops and livestock, power outage issues and depleted water reserves.
The U.S. Drought Monitor (USDM) is responsible for measuring drought conditions throughout the country and puts the drought conditions into categories: Abnormally dry (not drought), Moderate Drought (D1), Severe Drought (D2), Extreme Drought (D3), and Exceptional Drought (D4).
According to the USDM, the drought peaked when 87.99% of the state was in Exceptional Drought the week of Oct. 4, 2011 (see below).
Geoscientists at the University of Texas Jackson School of Geosciences dug deeper by looking at soil-moisture data from gravity and microwave sensors on satellites. That data was put into a land surface model to determine the severity of the drought in 2011. This new model simulation found the significant drought was more widespread and lasted longer than previously designated by the USDM. They also found that the Exceptional Drought covered as much as 95.1% of the state when peaking the week of April 5, 2011.
According to a news release from UT: ‘“The development of technology has allowed us to gain more real-time observation, and this observation can more accurately reflect the ground conditions,” said Weijing Chen, the study’s lead author and a postdoctoral researcher at the UT Jackson School of Geosciences.’
This means we can use new soil data and modeling that may not have been used years ago, to extrapolate back and adjust our understanding of drought conditions in the past. While the USDM does model soil moisture, the UT scientists were able to do so with greater detail and accuracy with their data analysis and modeling tools.
The results are quite apparent when comparing the UT model drought status (top picture) with the USDM drought status (bottom picture).
The differences showed the drought was both more severe and more long-lasting with the UT model than the USDM had found. From a time period perspective, the UT model also found drought was considered widespread in 2010, compared to the USDM estimate of widespread drought not beginning until 2011.
Having a better understanding of current and past drought conditions is very important to determining water resources for the state as well as potential disaster declarations and policy changes as a result of climate change.