A new approach to quantifying spatial contiguity using graph theory and spatial interaction

Abstract

Spatial contiguity is an important and fundamental landscape property in land allocation, habitat design, and forest management. The agreed upon notion of contiguity in the literature suggests shapelessness. However, existing approaches for measuring/promoting contiguity use proxies that either favour a particular shape or ignore inter‐patch relationships in fragmented landscapes. We propose an unbiased relative measure of contiguity ranging from zero to one based on graph theory and spatial interaction. The new measure reflects intra‐patch and inter‐patch relationships by quantifying contiguity within patches and potential contiguity among patches. Empirical analysis suggests that this measure of contiguity is reliable, consistent, and insensitive to sub‐region shape.

Keywords:

• Contiguity
• Fragmentation
• Landscape pattern assessment
• Reserve design
• Land‐use planning

Acknowledgements

This research was supported by the National Science Foundation (Geography and Regional Science Program and the Decision, Risk, and Management Science Program) under grant BCS‐0114362. Partial support for Wu was also provided by the Environmental Policy Initiative at The Ohio State University.