Overview of Connectivity Modeling Tools
Overview of Connectivity Modeling Tools
Numerous methods and tools have been developed and tested for modeling habitat connectivity. GIS-based modeling tools are continuing to evolve, as researchers and practitioners identify ways to improve on existing tools. Many of the tools are intended to model connectivity in terrestrial landscapes. Tools are also available for freshwater stream networks (Barrier Analysis Tool and Dendritic Connectivity Index) and marine environments (Marine Geospatial Analysis Tool). The terrestrially-oriented tools can be used to model either functional or structural connectivity; the key is to develop the input data sets according to whether you want to model general landscape permeability (structural connectivity) or connectivity for specific species (functional connectivity).
An Excel-based matrix summarizing the available modeling tools is available here. A general description of each tool is included, along with tools’ advantages and disadvantages, links to their websites, and other information. These tools are freely available on-line (or part of ArcGIS software) and readily used on a desktop computer.
Conservation Corridor also provides brief summaries of a number of the major tools currently in use or in development, as do the other connectivity tool websites.
Tool Limitations
While all of the tools will produce results indicating potential corridors or linkages or a broader indication of how readily a species may move through the landscape or stream network, they generally are not designed to account for the specific spatial extent and configuration of connections that the species of interest requires. While many tools place an increasing cost on increasing distance, specific requirements such as the width of a movement corridor or distances that the species will readily travel are not accounted for in the currently available tools. This is an overall limitation of these tools; when applying the model results, further interpretation is required to determine what areas may in fact serve as movement corridors or pathways for the species of interest.
Useful Aquatic Examples
- Martin, E. H. and C. D. Apse. 2011. Northeast Aquatic Connectivity: An Assessment of Dams on Northeastern Rivers. The Nature Conservancy, Eastern Freshwater Program.
- Forecasting the Impacts of Climate Change in the Columbia River Basin—Implications for Fish Habitat Connectivity (Great Northern Landscape Conservation Cooperative)