Visual Resource Management : Challenges Faced by the NPS

Visual Resource Management:Challenges Faced by the NPS

Suzanne GucciardoNatural Resource Specialist

Lewis and Clark National Historic Trail

Resource Information Management Conference22 April 2010

Ft. Collins, CO

Lewis and Clark National Historic Trail

• National Trail System Act (amended 1978)• 3,700 mile route of Corps of Discovery

– Historic route– Auto tour route

• Preserve trail remnants and artifacts• Administers through partnerships

Organic Act (16 USC 1)

…[The National Park Service] “shall promote and regulate the use of the Federal areas… by such means and measures as conform to the fundamental purpose of the said parks, monuments, and reservations, which purpose is to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations”

So what are visual resources?

Scenery Landscape ≠ or

Scenic resources

Visual resources includes both also dark skies, air quality related values

Scenic resources

• Interaction of forms and concepts:– Physical set of elements visible in space– Image in the viewer’s eye– Idea in the mind, a memory, a feeling in

the gut

Scenic resources• Have meaning

– Aesthetics– Historic and

cultural context

Increased threats to NPS scenic values

• External threats– Result of actions outside boundary that impacts

park– Affects views from park

• Internal changes– Result from natural or management changes

within park boundary– May affect both views within and into park

Land Use Change

• Conversion of ag/forestry lands• Urban sprawl• Commercial development

– Wal-Mart NP?• Rural residential development

– Viewsheds into parks

TIME FOR A QUIZ:

Which park is this?

Energy Development

Communication Systems

Climate Change

Internal Change

Park-based:Wind turbines to supplement power needsCommunication towers, antennasWater tanksService roads and buildingsVisitor service facilities

Vegetation Changes

NPS response to visual resource issues:

• NPS measures success of management by preventing “impairment”

• Currently no standard practice or guidance for measuring impairment to visual resource values

• No program area responsible for visual resources

• On a case by case basis, may include:– Viewshed analysis– Visual simulations – Public input

Viewshed analysis

• GIS based query• Spatial analyst• 3-D analyst• Choice of DTMs

– TIN – DEM

• Nine parameters can be set

• Google tool (Hey, what’s that!)– USGS DTM– Offset for viewer height

How Good are Viewshed Tools?

• Only as good as user– Even simple tools must be understood

Concerns with GIS Models

• Do not account for vegetation effects– ? Overcome with Lidar data– ? Available when needed

• “Casual” users versus dedicated GIS staff– Nuances may be missed and misleading

An Accuracy Assessment of Various GIS-based Viewshed Delineation

Techniques• Mark A. Maloy and Denis J. Dean• Photogrammetric Engineering & Remote

Sensing• Vol. 67, No. 11, November 2001, pp. 1293-

1298.

Compared field survey with GIS-based predictions of viewsheds

• 11 intermediate scale viewsheds west of Fort Collins, CO

• Field survey– GPS primary and secondary viewpoints– Angles from viewpoints to distinctive features

on boundary– Standard triangular geometry survey methods– Photography

Data sources and models• USGS data

– 1:24,500 scale DTM, 30-meter resolution– 1:24,500 scale DTM, resampled to 10 meters– 1:250,000 scale DTM, ~ 81.5 meters– 1:24,500 scale Hypsography, 10-meter

spacing• Single DEM model on each data set• Four TIN models on each set• 20 predictions for each of 11 viewsheds

Results

• GIS produced two types of errors– Omission

• Failed to detect areas surveyed within viewshed– Commission

• Included areas not surveyed within viewshed• Results varied greatly among models

– Mediocre results, even under best conditions

Average (across 11 viewpoints) Percent of Total Area

USGS 1:24,000 scale, 30-meter

GIS model TIN criteria

Surveyed & predicted visible

Predicted invisible (omission)

Predicted visible(commission)

DEM N/A 56.57 27.38 15.15

TIN Label 51.04 36.70 12.25

TIN 1 corner 54.01 25.03 20.96

TIN 2 corners 41.75 46.21 12.04

TIN 3 corners 18.95 76.47 4.59

Average (across 11 viewpoints) Percent of Total Area

USGS 1:24,000 scale, resampled to 10-meter

GIS model TIN criteria

Surveyed & predicted visible

Predicted invisible (omission)

Predicted visible(commission)

DEM N/A 54.18 31.42 13.18

TIN Label 51.25 37.56 11.19

TIN 1 corner 53.23 29.33 17.44

TIN 2 corners 38.04 52.96 9.01

TIN 3 corners 16.10 81.35 2.55

Average (across 11 viewpoints) Percent of Total Area

USGS 1:250,000 scale, ~81.5-meter

GIS model TIN criteria

Surveyed & predicted visible

Predicted invisible (omission)

Predicted visible(commission)

DEM N/A 27.28 33.97 35.79

TIN Label 17.22 39.11 43.67

TIN 1 corner 20.64 49.97 29.39

TIN 2 corners 12.50 34.70 52.80

TIN 3 corners 9.50 71.06 19.44

Average (across 11 viewpoints) Percent of Total Area

USGS 1:24,000 scale, hypsographic, 10-meter

GIS model TIN criteria

Surveyed & predicted visible

Predicted invisible (omission)

Predicted visible(commission)

DEM N/A 30.94 42.81 22.38

TIN Label 21.30 53.39 25.32

TIN 1 corner 24.19 43.04 32.78

TIN 2 corners 18.29 62.56 19.15

TIN 3 corners 8.21 83.82 7.97

Take Home Lesson

• GIS is not sufficient for supporting decisions– Field verification of viewsheds should be

standard• GIS can be misinterpreted

– Park management– Public

How should NPS respond to visual resource issues?

• Develop visual resource policy and program

• Take advantage other agency experience• BLM

– Visual Resource Management (since 1970s)• US Forest Service

– Scenery Management System (since 1970s)• NPS Blue Ridge Parkway

– Based on BLM VRM, must be adapted to local needs

BLM: Visual Resource Management System

• Complete program– Inventory– Analysis– Mitigation

• Mandated on all BLM lands

• Agency mission to support multiple use on BLM lands

Forest Service: Scenery Management System

• Mission to integrate forest production and multiple use

• Use best available tools wisely• Don’t rely on single method or analysis• Consult with other NPS staff or other

agencies to see what works, what doesn’t• Encourage NPS management to develop

guidance and standard practices

Short term response