This layer was created as part of Esri’s Green Infrastructure Initiative and is one of five newly generated companion datasets that can be used for Green Infrastructure (GI) planning at national, regional, and more local scales. If used together, these layers should have corresponding date-based suffixes (YYYYMMDD). The corresponding layer names are: Intact Habitat Cores, Habitat Connectors, Habitat Fragments, Habitat Cost Surface, and Intact Habitat Cores by Betweeness. These Esri derived data, and additional data central to GI planning from other authoritative sources, are also available as Map Packages for each U.S. State and can be downloaded from the Green Infrastructure Data Gallery.

This layer represents a cost surface for use in landscape connectivity modeling. It reflects the relative ease of movement for terrestrial species taking into account several factors including:  NLCD landcover classes, slope, proximity to water, and habitat core score. Generally speaking, natural land cover classes and areas proximal to water are parametrized to exhibit lower costs to species movement while developed areas and areas proximal to built infrastructure are parameterized to exhibit higher costs to species movement. 

Esri created this layer by following a methodology outlined by the Green Infrastructure Center, Inc. The cost surface was generated using a raster overlay process to create a composite comprised of several landscape variables. Characteristics within each variable were scored based on their perceived impact on species movement whereas reduced movement is reflected as high cost. Landscape variables were categorized into three themed classes based on their expected influence on the cost surface. The first class, impedance, represents the expected cost of species movement as it relates to land cover. The second class, bonuses, represents reductions in cost resulting from being within an existing core, fragment, or proximal to surface water; these conditions are assumed to enhance movement. The third class, penalties, represents increases in cost resulting from steeply sloping terrain and road infrastructure; these conditions are assumed to discourage movement.

This cost surface was used to generate a comprehensive network of Least Cost Paths (LCPs) using the Cost Connectivity tool which was introduced in ArcGIS 10.4 and ArcGISPro in 1.3. The resulting network was also utilized to compute Betweenness Centrality attribution for the Intact Habitat Cores by Betweenness layer, denoting a measure of the Core’s connectivity importance compared to all others in the network. This cost surface may be applicable for use in additional structurally focused landscape connectivity assessments and the generation of landscape corridors.

Data Coordinate System: NAD_1983_Albers