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.