Hydrologist maps an entire world of rivers
HydroSHEDS image of the Amazon basin. (WWF)
Hydrologist Bernhard Lehner has developed a database that provides high-resolution maps of river networks across the globe.
It’s called HydroSHEDS, and it’s useful to conservationists who work in regions where few people ever go – much less map. Scientists need information about these areas to understand Earth’s watersheds better, and manage endangered species.
The HydroSHEDS project began in the Amazon headwaters, around the border of Bolivia and Peru. Lehner and his colleagues at the World Wildlife Fund found that the maps they were using weren’t detailed enough. From one map to another, the rivers didn’t match up across national boundaries. So, Lehner and colleagues decided to make their own maps.
Bernhard Lehner: That’s when we started to build new data, our own, based on remote-sensing imagery elevation data basically.
The South American river maps took 2 years, as the software was being developed and thousands of corrections to the data had to be made manually.
Next were the maps of rivers in Asia, which took about half a year. Lehner expects the remaining continents to be mapped by the end of 2007. By the way, if you want to look at them, HydroSHEDS maps are now available online
.
Thanks today to NASA explore, discover, understand.
HydroSHEDS stands for Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales. The maps provide hydrographic information for regional and global-scales.
The HydroSHEDS team gave a map of the Tibetan watershed to the Dalai Lama. “It sparked a lot of discussion,” Bernhard Lehner said, “because it was so easy and fast to produce this map and show where the water’s actually flowing, and which people are dependent on this water, and making links.”
Download HydroSHEDS maps from USGS website
Overview of HydroSHEDS at the World Wildlife Fund
NASA’s Earth Observatory article on HydroSHEDS
Our thanks to:
Bernhard Lehner
Professor of global hydrology
McGill University
Montreal, Canada
(Freshwater GIS specialist
World Wildlife Fund)
Additional Teacher Resources
NASA: Earth Observatory – Remote River Reconnaissance
This article describes how space shuttle observations can help conservation biologists. It discusses the significance of using space-based topography data for understanding remote, poorly mapped regions. These remote regions contain some of the most intact biodiversity on Earth.
USGS: Science in Your Watershed
The U.S. Geological Surveys “Science in Your Watershed” web site allows you to find scientific information on your watershed. This information, coupled with observations and measurements made by the watershed groups, provides a foundation for characterizing, assessing, analyzing, and maintaining the status and health of a watershed.
U.S. EPA: Adopt Your Watershed
This web page provides links and information about environmental educational materials for students and teachers related to watersheds and water quality protection.
