Identification of enclaves and exclaves by computation based on point-set topology

Abstract

Enclaves and exclaves have special roles in geography and are of particular importance to fields such as (geo)politics and economy. However, enclaves and exclaves have not been defined with sufficient formality for automatic identification yet. To identify enclaves and exclaves more generally by computational means than current definitions existing in the literature, this article proposes expressive and generalized mathematical definitions of enclaves and exclaves based on point-set topology. A novel Boundary Extended 16-Intersection Model is developed in this article to identify enclaves, and 74 possible spatial configurations of enclaves are distinguished according to conditions of intersections for polygons in partitions and enclaves. The classic Dimensionally Extended 9-Intersection Model is employed to identify exclaves, and two possible spatial configurations of exclaves are distinguished according to conditions of intersections for polygons in partitions and exclaves. Applications of the proposed definitions are exemplified by the identification of enclaves and exclaves in prototypes and in the real world.

Keywords:

• Identification
• enclave
• exclave
• point-set topology

Acknowledgment

The author acknowledges the comments from anonymous reviewers and editors for helping improve the quality of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data and codes availability statement

The data and codes developed in this research are made available on the Figshare (https://doi.org/10.26188/14965596.v2).

Additional information

Notes on contributors

Xiaonan Wang

Xiaonan Wang is a PhD student at the University of Melbourne. Her research interests are spatial relations and semantics. Her contribution to this article includes research design, implementation, draft writing, and revision.