Droughts can travel hundreds to thousands of kilometers from where they started, like a slow-moving hurricane. A new study sheds light on how these droughts evolve in space and time, bringing vital new insight for water managers.
A small subset of the most intense droughts move across continents in predictable patterns, according a new study published in the journal Geophysical Research Letters by researchers in Austria and the United States. The study could help improve projections of future drought, allowing for more effective planning.
While most droughts tend to stay put near where they started, approximately 10% travel between 1,400 to 3,100 kilometers (depending on the continent), the study found. These traveling droughts also tend to be the largest and most severe ones, with the highest potential for damage to the agriculture, energy, water, and humanitarian aid sectors.
“Most people think of a drought as a local or regional problem, but some intense droughts actually migrate, like a slow-motion hurricane on a timescale of months to years instead of days to weeks," says Julio Herrera-Estrada, a graduate student in civil and environmental engineering at Princeton, who led the study.
The researchers analyzed drought data from 1979 to 2009, identifying 1,420 droughts worldwide. They found hotspots on each continent where a number of droughts had followed similar tracks. For example, in the southwestern United States, droughts tend to move from south to north.
In Australia, the researchers found two drought hotspots and common directions of movement, one from the east coast in a northwest direction, the other from the central plains in a northeast direction.
What causes some droughts to travel remains unclear, but the data suggest that feedback between precipitation and evaporation in the atmosphere and land may play a role.
"This study also suggests that there might be specific tipping points in how large and how intense a drought is, beyond which it will carry on growing and intensifying," said Justin Sheffield, a professor of hydrology and remote sensing at the University of Southampton. Sheffield was Herrera-Estrada's advisor while serving as research scholar at Princeton.
While the initial onset of a drought remains difficult to predict, the new model could allow researchers to better predict how droughts will evolve and persist.
“This study used an innovative approach to study how droughts evolve in space and time simultaneously, to have a more comprehensive understanding of their behaviors and characteristics, which has not been possible from previous approaches,” says Yusuke Satoh, a researcher at the International Institute for Applied Systems Analysis (IIASA), who also worked on the study.
The study also raises the importance of regional cooperation and of sharing information across borders, whether state or national. One example is the North American Drought Monitor, which brings together measurements and other information from Mexico, the US, and Canada, creating a comprehensive real-time monitoring system.
The researchers said the next step for the work is to examine why and how droughts travel by studying the feedback between evaporation and precipitation in greater detail. Herrera-Estrada also said he would like to analyze how drought behavior might be affected by climate change.
Herrera-Estrada JE, Satoh Y, & Sheffield J (2017). Spatio-Temporal Dynamics of Global Drought. Geophysical Research Letters: 1-25. DOI:10.1002/2016GL071768. http://pure.iiasa.ac.at/14387/
Katherine Leitzell | idw - Informationsdienst Wissenschaft
Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.
How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
14.12.2017 | Health and Medicine
14.12.2017 | Physics and Astronomy
14.12.2017 | Life Sciences