A Visual Assessment of Land Conservation Priorities for Viewsheds Along the Circuit Trails
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Protecting Significant Views Along The Circuit: A Visual Assessment of Land Conservation Priorities for Viewsheds Along The Circuit Trails Appalachian Mountain Club Presenters: Cathy Poppenwimer Mark Zakutansky Patricia McCloskey, AICP Photos: Montco Planning Commission Circuit Trails Visual Assessment Project Project Purpose ❑ Analyze Circuit Trails in suburban and rural areas to identify potential conservation land in a trail’s viewshed ❑ Viewshed: the area visible from a specific location along a trail ❑ Using GIS, develop a visual assessment and rank priority conservation areas ❑ Results can be used to conserve land with high scenic values to nearby trails ❑ Protect a quality trail experience and conserve important natural resources Photo: Montco Planning Commission The Circuit Circuit Trails Selected for the Study Trail ID Trail ID Trail ID No. PA Trails No. PA Trails No. NJ Trails 1 Baxter Trail 13 Pennypack Trail 25 Gloucester Township Trail 2 Big Woods Trail 14 Perkiomen Trail 26 Johnson Trolley Line Trail 3 Brandywine Trail 15 Power Line Trail 27 Kinkora Trail 4 Chester Creek Trail 16 Radnor Trail 28 Lawrence Hopewell Trail 5 Chester Valley Trail 17 Route 202 Parkway Trail 29 Monroe Township Bike Path 6 Cross County Trail 18 Schuykill River Trail 30 Pemberton Rail Trail 7 Cynwyd Heritage Trail 19 Skippack Trail 8 D&L Trail 20 Solebury Route 202 Trail 9 Darby Creek Trail 21 Struble Trail 10 East Branch Perkiomen Trail 22 Uwchlan Trail 11 Neshaminy Creek Trail 23 Wissahickon Trail 12 Pennsy Trail 24 Delaware & Raritan Canal Trail Study Methodology: A Visual Assessment of Individual Circuit Trails Viewshed Analysis ❑ Viewshed ❑ An area visible from a specific location ❑ Excludes areas beyond the horizon or obstructed by terrain and other features (e.g., buildings, trees). ❑ Data required to calculate a viewshed: ❑ Elevation ❑ Digital elevation model (DEM) - represents the bare earth. ❑ Digital surface model (DSM) - incorporates vegetation, buildings, powerlines and other objects above the bare earth ❑ An observation point or set of observation points ❑ Defines the locations and height from which a person would view a landscape. Viewshed Parameters Schuylkill River Trail Viewshed Parameters ❑ Based on a Digital Surface Model: ❑ 1-meter resolution, developed from 2006-2008 or 2015 LiDAR data ❑ Trail corridor – DEM values ❑ Observation Points ❑ Placed approx. 42 feet apart ❑ Observer height of approx. 6 feet above the ground ❑ Analysis was limited to 1 mile from the trail ❑ Visible grid cells that overlap forested canopy were expanded by two cells in every direction Parcel Assessment Parcels within the viewshed were analyzed based upon the following criteria: ❑ Visibility from the trail: Viewshed Area, Visual Magnitude, and Distance ❑ Scenic character within the trail’s viewshed: Landform, Landcover, Water, and Historic/Cultural Resources ❑ Key Observation Points (KOP): Significant views along the trail, identified by project partners ❑ Ownership Fragmentation: Parcel Size and Adjacency to Protected Areas Notes about the Study Methodology: ❑ The methodology was reviewed and approved by project partners ❑ Parcels not within the trail viewshed were removed from the analysis ❑ Each individual trail was evaluated separately Photo: Montco Planning Commission Visibility Resources ❑ Viewshed Area: amount of viewshed area within the parcel ❑ Visual Magnitude: indicates the number of observation points from which the area is visible ❑ Distance: how far the parcel is from the trail Schuylkill River Trail Scenic Resources ❑ Scenic Resources within the trail’s viewshed ❑ Landform or slope ❑ Landcover ❑ Forested ❑ Wetlands ❑ Hay and pasture ❑ Agricultural crops ❑ Water Resources ❑ Lakes ❑ Rivers/streams ❑ Historic/cultural resources Schuylkill River Trail Key Observation Points ❑ Significant views along the trail which may contain scenic, cultural or historic features ❑ Identified by project partners ❑ For each KOP the viewshed area and parcel distance was calculated Schuylkill River Trail Ownership Fragmentation ❑ Parcel size ❑ Adjacency to protected areas Schuylkill River Trail Visual Assessment Methodology Flow Chart Visibility Component: Visibility Viewshed Area (1-10) • Combined visibility components • Determined 10 classes based on natural Visibility Component: breaks classification (GIS determined) Visual Magnitude (1-10) • Ranked using a 1-10 scale (1 = lowest value and 10 = highest value) Visibility Component: ❑ A Combined Parcel Value (CPV) Distance Zones (1, 3, 5) score was developed by adding Scenic Character Component: visibility, scenic character, KOP, and Land Form/Topography (2, 6, 10) Scenic Character • Combined scenic character components ownership fragmentation scores. Scenic Character Component: • Determined the parcel’s mean composite Landcover (4, 6, 10) value ❑ The CPV score identifies parcels • Determined 10 classes based on natural Scenic Character Component: breaks classification with the highest value for Water (8, 10) • Ranked using 1-10 scale (1 = lowest value and 10 = highest value) conservation based on resource Scenic Character Component: Combined Parcel Value Historic/Cultural (8) • Combined visual, scenic values and landscape context. character, KOP and ownership Key Observation Points: Based on fragmentation resources visibility resources for Key • Values: 1 – 33 (1 = lowest value Observation Points (1-3) and 33 = highest value) Ownership Fragmentation Component: Parcel Size (1-5) Ownership Fragmentation • Combined parcel size and Ownership Fragmentation adjacent to protected areas, Component: Adjacent to Protected values = 1 - 10 Areas (1-5) Questions on the Methodology? Visual Assessment Pilot Project In 2017, a pilot project of an eight mile section of the Schuylkill River Trail was initiated. During the pilot project: ❑ Circuit Trails to include in the full study were determined ❑ A stakeholder list was developed and outreach was conducted ❑ Study methodology was refined and tested ❑ The Wikimapping project for key observation point (KOP) collection was developed ❑ Results of the pilot project were included in a separate report Visual Assessment Project Example 1: Schuylkill River Trail Photo: Schuylkill River Trail, Bicycle Coalition of Greater Philadelphia Example 1: Schuylkill River Trail Schuylkill River Trail: Study Area and Viewshed ❑ Study area: an 8.8 mile section of Schuylkill River Trail from Pottstown to Birdsboro Montgomery ❑ Study area extends one mile on both County side of the trail (12,900 acres) ❑ The trail’s viewshed developed from the digital surface model (DSM) is Berks roughly 483 acres or 4% of the study County area ❑ Over 1,558 unprotected parcels encompassing over 3,970 acres are Chester County potentially available for conservation protection Schuylkill River Trail: Visibility Resources ❑ Of the 1,558 unprotected parcels Montgomery in the viewshed, 1,178 have a County score of 1 (lowest) and one parcel has a score of 10 (highest). ❑ Of the 83 protected parcels, one Berks County parcel has a score of 10 (shown in red). Chester County Schuylkill River Trail: Scenic Resources ❑ Acres with scenic character: 321 Montgomery (66%) County ❑ Of the 1,558 unprotected parcels in the viewshed, 577 have a score of 1 (lowest) and five (5) parcels have a score of Berks County 10 (highest) Chester County Schuylkill River Trail: KOP Resources ❑ Total viewshed: 50 acres ❑ 1-Remains of Schuylkill Navigation Canal (16 parcels) ❑ 2-Schuylkill River from Douglassville Bridge (23 parcels) ❑ 3-Former Stanley Flagg Steel Company site (218 parcels) ❑ 4-Manatawny Creek Bridge, Pottstown (2 parcels) ❑ 5-Schuylkill River from Riverfront Park, Pottstown (2 parcels) ❑ Total KOP parcels: 260 ❑ One of the 260 parcels can be seen from more than one KOP (KOPs 4 and 5) Schuylkill River Trail: Ownership Fragmentation and Combined Parcel Value Score Ownership Fragmentation: ❑ 74% are less than 1 acre in size. Four parcels over 174 acres in Montgomery size represent the top 15% of County parcels. 203 unprotected parcels are adjacent to existing protected open space areas, ranging from Berks less than 1% to 80% adjacency. County Combined Parcel Value Score: ❑ The highest CPV score represents the top 5% of parcels. Chester Eight unprotected parcels have a County high score. Schuylkill River Trail: Highest Ranked Parcels ❑ The highest ranked parcels represent the combined parcel value score which includes scenic, visibility, KOP and ownership fragmentation resources values Montgomery County ❑ Includes unprotected and protected parcels Berks County Chester County Photo: Montco Planning Commission Schuylkill River Trail: Highest Ranked Parcel Example ❑ Results of the visual assessment of Section 3 of the Schuylkill River Trail reveal several unprotected parcels within the trail study area and viewshed ❑ Higher elevation portions of this parcel are visible from the SRT ❑ Ranked high for visibility resources ❑ Ranked medium for scenic resources Chester ❑ Ranked medium for KOP County resources (KOP#3) Visual Assessment Study Data Distribution Sheet: Schuylkill River Trail Visibility Component Scenic Character Component Key Observation Points Component Ownership Fragmentation Component Trail Conservation Combined Parcel Value Ownership - Combined Parcel Value Score Rank (High = top Federal, State, Score (Visibility 5% ranked parcels, County, Resources Rank + Scenic Medium = next 10% Parcel Municipality, Character Resources ranked parcels, and Protected Private or Rank + KOP Rank +Size Low = remaining Visual Magnitude