100 Years of Data Is Not Enough to Establish Reliable Drought Thresholds, Finds Wild

A dry desert, with severely cracked ground surrounding a dry tree stump

ESSIC Assistant Research Professor Thomas Wild has a new article in the Journal of Hydrology titled “100 years of data is not enough to establish reliable drought thresholds”.  Wild’s co-authors include Robert Link, Abigail Snyder, Mohamad Hejazi, and Chris Vernon from the Joint Global Change Research Institute.


One major projected effect of global climate change is its potential to affect the timing and incidence of drought.  However, no universal definition of drought exists– instead, drought is commonly defined by using a threshold.  If an observed hydrological variable drops below the threshold at a location, the location is considered to be in a drought.


As the title of the article suggests, the researchers found that thresholds determined from historical records can have substantial uncertainties, and that the record length needed to control that uncertainty to an acceptable degree is longer than is generally acknowledged.


This is critically important for the hydrology community to consider as researchers attempt to project the implications of climate change for global drought hazard.  This is a subject of a follow-up study that the team is currently conducting.  During this follow-up work, the researchers found that the outcomes of global drought hazard analysis depend heavily on the definition of highly uncertain drought thresholds.


Dr. Wild is also jointly appointed as a Research Scientist at the Pacific Northwest National Laboratory’s Joint Global Change Research Institute.  His background is in systems analysis and hydrology, with a focus on developing and applying novel modeling tools and decision support frameworks for solving complex systems problems that occur at the intersection of disciplines.  His research has focused on water resources and environmental systems, and has contributed to identifying and mitigating food-energy-water tradeoffs and conflicts, developing sustainable hydropower systems, managing fluvial and stormwater quality, and equitably sharing transboundary resources.


To access the article, click here: “100 years of data is not enough to establish reliable drought thresholds”.