Using Remote Sensing to Understand Climate Change Effects on Wetland Ecosystems

Semi-arid wetlands might sound like an oxymoron—until you are wading into one surrounded by snow (see right).

Field verifying the condition of such wetlands in the sage-shrub steppe of Douglas County, Wash., is part of a research project led by Meghan Halabisky of Professor Monika Moskal’s Remote Sensing and Geospatial Analysis Lab (RSGAL). The goal of Halabisky’s research is to inventory wetlands in the Pacific Northwest and understand what will happen to these vulnerable ecosystems as the climate changes. These understudied yet ecologically important ecosystems are critical habitat for amphibians, migratory birds and rare plant species.

Aerial Imagery

Example of wetland classification using high-resolution aerial imagery; ponds are colored blue, while emergent wetland vegetation are colored in green.

It can be challenging to study wetlands at the landscape scale because they occur on both public and private lands and can be difficult to access. In addition, little is known of their dynamic hydrology as it requires frequent monitoring. That’s why remote sensing is a key tool in understanding the spatial and temporal relationships of wetlands across the landscape.

Through the of use of high-resolution aerial imagery, multiple years of Landsat satellite imagery and cutting-edge remote sensing techniques, the RSGAL team—which also includes Chris Vondrasek, Lopamudra Dasgupta, Michael Hannam and Stephanie Kong—is able to both identify wetlands and reconstruct historical changes in wetland function. This function includes changes in wetland hydrology, surrounding land use and water pollution of wetlands.

The RSGAL team’s field verification work includes measuring water depth of depressional wetlands and placing multiple sensors (ibuttons) at different wetland elevations to measure the seasonal fluctuation of water levels.

Field verification

The RSGAL team measuring water depth of depressional wetlands.

This research is part of an interdisciplinary project to develop hydrologic projections for diverse wetland habitats (e.g. forest wetlands, wet meadows, small ponds and riparian wetlands) across the Pacific Northwest for the 2020s, 2040s and 2080s. The projections can be used to support ecological and landscape-based vulnerability assessments and climate change adaptation planning.

For more background on this project, listen to an interview Chris Vondrasek put together!

Photos courtesy of Meghan Halabisky and Chris Vondrasek.

Going Rogue in Oregon

Rouge River

Sunlight filtering through the trees and canyons on the way back to the crew’s BLM house on the Rogue River. “It was the perfect end to every day working underneath the Douglas-firs,” says Putz.

This past summer, a five-person crew from the School of Environmental and Forest Sciences (SEFS) set out to conduct research along the Rogue River in Oregon. Working as part of Professor Monika Moskal’s Remote Sensing and Geospatial Analysis Laboratory, the students collected data of red tree vole habitat for the Bureau of Land Management (BLM) from May to September.

Their research proposed to answer several questions, including whether survey grade GPS can be used to accurately acquire individual tree location from LiDAR data (light detection and ranging), and whether ground-based inventory and leaf area measurements can be used to drive LiDAR-based empirical habitat models for the Rouge River site. The project will ultimately help the BLM develop a method of analyzing LiDAR data for forest inventory and management.

“Spending the summer in the Rogue River Valley working with amazing people and learning useful techniques taught me the importance of fieldwork, our forests and the animals that inhabit them,” says Tessa Putz, an undergraduate ESRM major with the SEFS crew.

“Working for BLM this summer was a great experience,” says PhD candidate Gonzalo Thienel, another member of the SEFS team. “I learned many things about nature, remote sensing and teamwork.”

Not bad for a field site!

Photo of the Rogue River © Tessa Putz/SEFS.