A Texas A&M University professor has helped produce what may be the most precise and detailed map to date of the planet’s bodies of water.
George Allen, an assistant professor of geography at Texas A&M, said that the MERIT Hydro map could help scientists predict flooding events and allows for better and more thorough water management.
“For hydrologists, because we have a better representation of where water will flow, we get a better idea of translating weather data — like precipitation information — into actually understanding where the water will go and flow, how big a flood will be or what will happen if there’s a drought.”
Allen said that if and when flooding occurs, the MERIT Hydro map will help hydrologists and others understand where water will go and how deep it may go once it spreads.
“Before this data set, there were similar data sets out there, and they were primarily developed from single sources — usually satellites with radar mapping out elevation of the surface of the Earth,” Allen said. “And that works pretty well as an approximation for where water is, because as we know, water travels downhill and accumulates at the bottom of valleys, and you can predict how big a river might be at the bottom of a given valley.”
The breakthrough of this data set, Allen continued, is that the team of researchers combined satellite data sets with crowdsourced data and other specific information about individual bodies of water to create a more comprehensive understanding of elevations.
“That really improves our ability to know where water flows,” Allen said.
“We can use satellite imagery to correct the maps of elevation,” Allen said. “For example, small errors in a digital elevation model may cause a river’s course to deviate hundreds of kilometers in the wrong direction. But satellite imagery will show the actual location of the river. MERIT Hydro uses the measured location of the rivers, lakes and canals to automatically correct its map of topography.”
Allen said that the data set is static and is not a forecast model itself, but may be used for myriad predictions and other flood modeling.
Allen said that the MERIT Hydro map also includes information about bodies of water in the Arctic, unlike one of the two most commonly used data sets.
“Not only is it a better representation of the Earth’s hydrography, it’s the first high-resolution fully global data set,” Allen said. Now we have the data in the Arctic, which is really great, because now, as hydrologists, we can say that we are actually modeling the entire Earth.”
Dai Yamazaki at the University of Tokyo led the team of scholars and researchers, Allen said.
He added that his areas of research focus include surface hydrology and remote sensing of streams and rivers.
According to Allen, the MERIT Hydro map may also be used to simulate river flow on a global scale. It can be used to understand biogeochemical processes that release significant levels of greenhouse gasses to the atmosphere.