Health infrastructure under pressure: spatial-temporal analysis of King Saud Medical City expansion

King Saud Medical City (KSMC), Riyadh's largest public medical city, has undergone a profound spatial and institutional transformation between 2000 and 2025. Using multi-temporal remote sensing and geographic information system analysis, this study provides quantitative evidence of medical city densification in Saudi Arabia. The built-up footprint expanded by more than 19 hectares, and the Normalized Difference Built-up Index increased by +0.36, reflecting a shift from a low-rise, dispersed campus to a vertically integrated medical complex. This physical transformation coincided with major institutional growth: total bed capacity increased from approximately 450 to over 1,500, including 200 intensive care beds; the emergency department expanded to 102 beds, becoming one of the largest in the Kingdom; and annual surgical volume exceeded 20,000 major procedures. These changes occurred alongside rapid population growth in Riyadh and national health system reforms such as the Medical Cities Law, the Health Cluster Model, and Vision 2030. The findings demonstrate how spatial densification enabled operational expansion and accelerated the adoption of advanced medical infrastructure. The study offers a scalable spatial framework for guiding the future development of large medical facilities in rapidly urbanizing settings.