Derivation of a resilient polygon centroid for natural resource management applications

Abstract

This paper reviews the utility of polygon centroid algorithms for natural resource management applications. Following a review of ‘standard’ centroid derivation algorithms, and their limitations, alternative approaches are proposed. Building upon current polygon-reduction algorithms an iterative edge-erosion model is presented. Resilient centroids derived via this model are shown to: (1) maximise the distance to all internal and external edges; (2) be located within the polygon boundary; and (3) be insensitive to patch vertex outliers.

The resilient centroid is demonstrated to have utility in a range of natural resource management applications including the matching of disparate data sources. Exemplar studies conclude that resilient centroids support an appropriate allocation of vegetation condition point samples both within and between native vegetation patches. Further, the utilisation of resilient centroids enables the (1) sub-division of vegetation patches into homogenous regions (core areas) and (2) interrogation of the relationship between vegetation condition and core area proximity.

Keywords:

• centroid
• polygon-shrinking algorithms
• resilience

Acknowledgements

We gratefully acknowledge the expert input of Dr. Graeme Newell and staffs at the Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Victoria, Australia. Financial assistance was provided by the Australian Commonwealth Environment Research Fund, ‘Landscape Logic’ project and is gratefully acknowledged.