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Publication Date
11 September 2017

Xanthos – A Global Hydrologic Model

Scientists developed an open-source tool that simulates past and future global water availability.
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Freshwater resources are finite and unevenly distributed, yet the demand—and competition—for freshwater is expected to grow, which may affect future freshwater resources. A team at the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL) developed Xanthos, an open-source hydrologic model that helps researchers quantify and analyze global water availability. 


Researchers can use Xanthos to explore different climate, socioeconomic, or energy scenarios over the 21st century, and assess their effects on regional and global water availability. Xanthos can operate as an independent model or serve as the core freshwater supply component of the Global Change Assessment Model (GCAM). It also can be used by other integrated assessment models that focus on energy-water-land interactions. 


Xanthos, an open-source hydrologic model written in Python, simulates historical and future global water availability on a monthly time step at a spatial resolution of 0.5 geographic degrees. Scientists designed Xanthos to be extensible and used by researchers who study global water supply and work with GCAM, also developed at PNNL. Validated with global data sets, Xanthos includes modules for calculating potential evapotranspiration, runoff generation, and stream routing. Researchers are able to customize Xanthos’ configuration file to specify model inputs, outputs, and parameters. Xanthos can provide historical observations and future estimates of renewable freshwater resources in the form of total runoff. The model’s modular and flexible structure is intended to promote community engagement, enabling users to integrate their own research through extensible modules.

Point of Contact
Mohamad Hejazi
Pacific Northwest National Laboratory (PNNL)
Funding Program Area(s)