Urban Expansion and Landscape Pattern Dynamics in Urban Agglomerations: A Case Study of the Guanzhong Plain Urban Agglomeration, China

Urban agglomerations serve as crucial spatial carriers for advancing people-centered new urbanization. However, the integrated analysis of urban expansion dynamics, landscape pattern responses, and their driving mechanisms, particularly in ecologically sensitive, late-developing urban agglomerations, remains insufficiently understood. Taking the Guanzhong Plain Urban Agglomeration (GPUA) as the study area, this paper utilizes the Urban Expansion Rate Index (UERI), Urban Expansion Intensity Index (UEII), Landscape Expansion Index (LEI), and Landscape Pattern Metrics (LPMs) to examine urban land expansion and landscape pattern changes, and employs GeoDetector to analyze the driving forces behind these changes. The findings indicate that from 1990 to 2020, the urban land area of the GPUA expanded continuously, with UERI and UEII showing an “increase-then-decrease” trend. Significant disparities exist among cities in the urban expansion areas, with the coexistence of “edge” and “infilling” modes profoundly influencing landscape responses. The driving forces of urban expansion have undergone a stage-specific transition from socioeconomic dominance to ecological policies and natural constraints, with policy–institutional control, socioeconomic development drivers, natural endowment constraints, and improved locational conditions collectively shaping the GPUA’s “spatial landscape” system. The findings of this study provide a scientific basis for territorial spatial governance and sustainable development in ecologically fragile urban agglomerations.