Landscape Dynamics Monitoring

Avalanche path in vicinity of Dagger Lake North Cascades National Park

NPS photo from 2008

Importance

From year to year, any number of events can alter landscapes in and around North Coast and Cascades Network parks, including landslides, fires, clearcuts, and human development. These landscape changes occur at a wide variety of scales of time, extent, and magnitude, from a small flood that scours a riparian zone to a large fire that burns thousands of acres. Regardless of size and severity, each event can have lasting effects on the rest of the ecosystem, which include changes in hydrologic regimes, nutrient cycling, water quality, distribution of exotics, and quality of wildlife habitat. The Landscape Dynamics monitoring program detects and maps where these landscape changes occur, how severe they are, and how long they last. The goal of this program is to document current rates of landscape change providing a baseline against which human-induced change can be compared in the future.

Parks Monitored

• Ebey's Landing National Historical Reserve*
• Lewis and Clark National Historical Park
• Mount Rainier National Park
• North Cascades National Park Complex
• Olympic National Park
• San Juan Island National Historical Park*

Monitoring Objectives

The landscape dynamics monitoring program uses satellite imagery, Geographic Information System, and statistical analysis to evaluate landscape changes in and around network parks. The program tracks the size, duration, and intensity of each landscape change. The specific objectives are to:

• Detect and map landscape changes that are larger than 0.8 ha (2 ac) resulting from an avalanche, clearing, development, fire, mass movement, progressive defoliation, riparian flooding, or tree toppling.
• Determine trends in the size, magnitude, location, and spatial distribution of each landscape change category.

Basic Approach

Each year, Landsat images undergo analysis using a program called Landsat-based Detection of Trends in Disturbance and Recovery (LandTrendr) to detect new areas that have changed compared to the previous year. Individual patches larger than 0.8 ha (2 acres) and where at least 10 percent of the vegetation has been removed are delineated. Next, the patches are labeled with a change agent, such as fire, mass movement, clearcut, or riparian flooding. To create the label, a statistical model combines information about the patch’s shape, size, and location on the landscape with the information about the event duration and magnitude from the Landsat images. For example, a square-shaped patch outside the park boundary in which a tall forest canopy has been removed and only bare ground remains is likely to be a clearcut. Maps of the change areas are created for each park every three years.

Management Applications

• Provide knowledge about trends in the size, frequency, or severity of landscape change events for land management and facilities planning.
• Provide a landscape-scale context for interpreting trends documented in other North Coast and Cascades Network monitoring projects.

By documenting landscape change over long periods, North Coast and Cascades Network National Parks can better assess the risks of climate change to natural and cultural resources.

*Landscape Dynamics monitoring methods for these two parks in development

Reports and Documents

 

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