Scientists at the International Center for Integrated Mountain Development (ICIMOD), a Nepal-based research institute, and colleagues at Utrecht University in the Netherlands used unmanned aircraft systems to map the Lirung glacier in Nepal in 2013. Their results will appear in the July issue of the journal Remote Sensing of Environment.
“With repeated field missions, we get an amazingly detailed look at how the surface of the glacier is changing, and use that to build better models of glacier melt.” –Joe Shea, hydrologist International Center for Integrated Mountain Development
The researchers found that the 3.5-kilometer long glacier is losing mass at relatively low rates, but that melting is much higher along ice cliffs and around the small lakes that pool on top of the ice.
For those insights, the researchers can thank a piece of technology that appears as sturdy as cardboard and fits in a suitcase.
Fitted with a point-and-shoot camera and a GPS, the $US 16,360 SenseFly eBee was programmed to fly certain patterns over the glacier, said Joe Shea, a glacier hydrologist at ICIMOD who worked on the study.
At predetermined points, the onboard software told the camera to take photos. After the flight, the photos were combined with ground measurements to produce high-resolution digital maps of the glacier’s exterior.
As they repeat the process, the researchers will develop a chart of glacial changes. Coupled with data on rain and snow, the glacier maps will help identify how climate change will alter rivers that supply some 1.3 billion people with water.
“With repeated field missions, we get an amazingly detailed look at how the surface of the glacier is changing, and use that to build better models of glacier melt,” Shea wrote in an email to Circle of Blue.
Better models and better knowledge of individual glaciers is important in the Himalayas where glacier behavior varies significantly from valley to valley and range to range. Melt water from glaciers is just one of three components of Himalayan river flows, the other two being seasonal rain and snow melt. The latest report from the Intergovernmental Panel on Climate Change states that glacier characteristics in this region “are still only poorly known.”
The drone study shows that technology will assist researchers in a region where field work is daunting. Even the drones are prone to malfunction in the thin air. Shea said there were a few failed takeoffs at the work station at 4,700 meters (15,420 feet) above sea level.
Shea’s colleagues are also bullish on the new research methods.
“During the last few years, we’ve come a long way, and we’ve focused mostly on modeling and satellite remote sensing, but to really understand what is happening on the ground we need to use technology like the UAVs and high-altitude precipitation instruments to understand the impacts of climate change,” said Walter Immerzeel, a hydrologist at Utrecht University who helped with the study.
“We’ve now shown that this is very well possible in one catchment in Nepal, but the variation throughout the Himalayas is so large that we have to extend this technology throughout the entire region,” Immerzeel said.
Source: Circle of Blue