Wilderness Character Mapping

A riverside view of the Kobuk River. Both proposed routes for Ambler Road would cross the river.

The condition of wilderness character varies across a wilderness based on the intensity and distribution of human influences that degrade it. Just as variation in other landscape features can be depicted spatially, so too can the condition of wilderness character. Gates of the Arctic National Park and Preserve is the first wilderness within the National Wilderness Preservation System to use wilderness character mapping to model potentially impacting future scenarios. Specifically, maps include potential impacts of two proposed industrial road routes through the preserve.

Methods

A set of measures was identified by the project team to capture impacts to the five qualities of wilderness character (untrammeled, natural, undeveloped, solitude or primitive and unconfined recreation, and other features of value). These measures were depicted using a variety of spatial datasets, which were normalized using a common relative scale such that disparate metrics could be analyzed together. Each measure was “weighted” by the project team (using a 10-point scale) to reflect its relative impact to wilderness character. Maps generated for each of the weighted measures were then added together to produce a composite map of impacts to wilderness character. In addition, maps were generated to depict positive features of value and impacts posed by the potential development of an industrial road corridor through the southern portion of the park. The map products delineate the spatial pattern and variation of impacts to wilderness character across the park.

The baseline and proposed Ambler Road corridor maps depict the park’s current degree of departure or degradation from an optimal condition of wilderness character. This optimal condition reflects a manifestation of wilderness character as expressed in the Wilderness Act—in other words, a state in which there are no or minimal impacts to wilderness character. Each measure is depicted on a scale from its optimal condition (i.e., no impact) to its most degraded condition (i.e., highest current impact level). When the measures are combined accumulatively, therefore, the overall map of impacts to wilderness character is similarly depicted on a scale from its optimal condition (i.e., no impacts to wilderness character) to its most degraded condition (i.e., highest cumulative impact level from all measures).

Results

The resulting maps include degrad-ations to wilderness character from the developments explicitly described in AIDEA’s Ambler Road right-of-way application, and estimated additional degradations of wilderness character that could occur should the Ambler Road become a public access route. The project team chose to map both explicit and estimated degradations of wilderness character to foster consideration of reasonably foreseeable outcomes of road access being introduced through large tracts of public (both state and federal) lands, including public access to and increased recreational visitation of lands within the park. This approach also allows managers to foresee impacts from types of visitor use previously unseen in the area.

The resulting maps show the proposed northern road corridor will have a larger footprint through the Kobuk Preserve, and thus a greater impact on wilderness character in the area, than the proposed southern route. The northern corridor is in close proximity to two large lakes (Walker Lake and Nutuvukti Lake), which are likely to attract visitors and may eventually require facilities (such as campsites, restrooms and trails) and management restrictions to protect resources.

Potential threats to wilderness character based on the proposed northern (top) and southern (above) routes for the Ambler Road. The impacted area of the proposed northern route is 3,141 sq. km. and the unaffected area is 30,148 sq. km. For the proposed southern route, the impacted area is 2,494 sq. km and the unaffected area is 30,796 sq. km. In addition, the northern route is in close proximity to park wilderness and lakes that are likely to attract increased visitation and associated impacts.

Green depicts optimal condition and yellow to brown depicts degraded condition.

Analyzing the impacts of the two proposed corridors on currently designated wilderness and areas managed as wilderness, it is clear that the northern corridor will have a greater impact on wilderness character than the southern corridor.

For More Information

Pace, K. K., J. Tricker, A. Baltensperger, and P. Landres. 2017. Mapping wilderness character in Gates of the Arctic National Park and Preserve. Natural Resource Report NPS/GAAR/NRR—2017/1446. National Park Service, Fort Collins, Colorado.