Occurring frequently over the Southern Plains, droughts are the second most costly U.S. weather and climate disaster. In 2011, a devastating drought impacted Texas, Oklahoma, and nearby states, causing damage estimates of $14 billion and was responsible for 96 deaths. Evidence shows the 2011 Texas drought was accompanied by decreased terrestrial water storage and suppressed vegetation activity. Many efforts have been made to advance drought monitoring. However, modeling water availability during drought remains challenging as numerous physical processes control soil moisture variability. Therefore, it is important to examine the physical process that controls water availability during drought to understand the mechanisms causing the disparities between models.

In a new Journal of Hydrometeorology, authors Wen-Ying Wu, Zong-Liang Yang, and Michael Barlage investigate the critical hydrometeorological processes during drought using the land surface model Noah-MP to simulate water availability and investigate the causes of the record 2011 drought. Using a series of experiments with runoff schemes, vegetation life cycles, and plant rooting depth, observation-based terrestrial water storage, evapotranspiration, runoff, and leaf area index are used to compare the results from the model.