Patterns and trends in land-use land-cover change research explored using self-organizing map

Abstract

Research on land change has a long history, has generated numerous publications and continues to receive international research attention. To facilitate the understanding of the patterns and trends of land-change research, this article uses a content-based text-retrieval approach and self-organizing map to analyse more than 700 peer-reviewed remote-sensing and natural-science papers on land-use/cover change (LUCC) from the past two decades. We present the results in map-like displays and discuss papers within the identified clusters to examine the research activities. A new cluster of research, which has emerged in the last 5 years of analysis, has focused on mixed-pixel issues for land-use/cover mapping, particularly in the context of forest catchments. Studies of LUCC consequences after 2000 have been concerned with the effects of forest conversion on soil-nutrient pools and nitrate cycling. Incorporating information on resolutions and extents into the representations reveals a dominant scale of analysis for some research activities. Analysing time frames of examination in the papers suggests that research on long-term LUCC consequences started to use presettlement land survey records. Few attempts, however, have been made to investigate the uncertainties in the historical sources of information for LUCC research, thereby presenting a future research topic.

Acknowledgements

The National University of Singapore provided funding (Grant no. R-109-000-070-101) for this research. We thank André Skupin for his valuable suggestions on the analysis; Seeleng Quek, Cheryl Chen and Huan VuDuc for their help in preprocessing the text files; Yikang Feng for his assistance in mapping and two anonymous reviewers for their helpful and encouraging comments.