Visualisation of High-Density City Research Evolution, Trends, and Outlook in the 21st Century

High-density cities are growing in number and importance due to globalisation, significantly contributing to local, regional, and worldwide economies. It is progressively becoming clear that the high-density features of cities are associated with the frequency of disasters. As more than half of the world's population currently resides in cities, the study of high-density cities is evolving into an academic topic. In this study, the WoSCC (Web of Science Core Collection) and CiteSpace software were used to visualise and analyse the development history, current status, hotspots, and trends in high-density city research. We analysed a total of 377 valid articles spanning 2001 to 2022. This research aimed to illustrate the trajectory of high-density city development and to summarise the field's research hotspots and development history after entering the 21st century. It is hoped that this study will provide a theoretical reference and development direction for the future development of the field of high-density city research. Our results indicate that more publications have used the relevant keywords over time and that the research has overall trended from general to specific, noticeably changing in response to urban modernisation. Academic study in this area is still in its early stage. Instead of an inherent urge to spontaneously advance due to academic output, the research field has primarily grown in response to urban problems. COVID-19 has also hastened urban infill, further impacting existing high-density communities' urban environments, transportation infrastructure, and economies. The global epidemic has added urgency to research on high-density cities, and new content and directions are being developed. Assessing the hazards of high urban density while maximising its economic role is a significant part of academic research on high-density cities at this stage and will remain so in the future.