In the past century, global urbanization has profoundly influenced human society. As a worldwide phenomenon, urban expansion represents one of the most significant anthropogenic impacts on the terrestrial environment (Horn and Van Eeden, 2018; Amponsah et al., 2022; Zhuang et al., 2023). By 2030, the land area occupied by cities globally may increase threefold (Alberti, 2005). The expansion of urban construction land is characterized by spatial scale enlargement, morphological adjustments, density renewal, and temporal succession (Wachsmuth et al., 2016). However, there remains a paucity of detailed studies examining urban landscape ecology across various industrial clusters, which constrains our understanding of the interplay between the development of functional urban clusters and landscape ecology at medium and micro scales. To sustain vibrant economic and social growth in urban areas, it is essential to harmonize the relationship between urban expansion and landscape ecology to ensure that urban ecosystems evolve towards livable ecological environments.

During the process of urban expansion, the ongoing growth and concentration of populations and industries significantly alter the landscape ecological pattern (Salvati et al, 2018), profoundly impacting urban life, habitation, and production activities (Grimm et al., 2008). The transformation of agricultural land into developed urban areas results in impervious surfaces such as roads, standalone commercial complexes, and densely populated residential zones, thereby transforming the original natural ecological landscape pattern (Tanner and Fuhlendorf, 2018; Wang et al., 2019). This alteration in landscape configuration leads to spatial characteristics marked by high overall fragmentation and localized patchiness, which disrupts the integrity of urban ecosystems, affects biodiversity distribution, and influences travel behaviors among urban residents. Concurrently, the outward spread associated with urban expansion heightens both the frequency and intensity of natural disturbances while introducing new disruptions or prolonged pressures that inflict unprecedented damage on the landscape ecological patterns (Feng et al., 2020), consequently altering nutrient cycling and energy flow within natural systems (Berling-Wolff and Wu, 2004; Lu et al., 2023). Conversely, changes in landscape patterns can reflect significant transformations in the structure, processes, and functions of urban ecosystems. Such shifts may render heat waves, waterlogging events, and air pollution as potential threats to urban ecology (Gasper et al., 2011; Gibb et al., 2020), leading to increased ecological vulnerability while diminishing resilience within cities (Strohschon et al., 2013; Pickett et al., 2014). Nevertheless, research on the interplay between urban spatial expansion and changes in landscape ecological patterns has largely overlooked the differentiated impacts and responses induced by the new-type spatial development model. Most pertinent studies have quantified urban expansion within a spatiotemporal framework to ascertain the correlation between urban expansion and alterations in landscape ecological patterns (Jaeger and Schwick, 2014; Li et al., 2015). The scope of these investigations ranges from individual cities to multiple cities and urban agglomerations. For instance, Darrel and Potere (2010) conducted a comparative analysis of landscape pattern changes across 120 cities globally, while Ran et al. (2023) examined landscape patterns and ecosystem health in 212 major Chinese cities. Nearly all findings indicate that metropolitan expansion and urban expansion lead to fragmentation, complexity, and heterogeneity in landscape patterns (Bosch et al., 2020; Wu et al., 2011). Methodologically, the impact of urbanization on landscape patterns is typically assessed quantitatively through indices of landscape patterning as well as Morphological Spatial Pattern Analysis (MSPA), with most indicators being integrated into spatiotemporal gradient analyses (Salvati, 2014; Zhang and Wang, 2023). Additionally, some studies incorporate nighttime lighting data to monitor shifts in urban landscapes and simulate economic activities within these areas (Li et al., 2019). However, there remains a scarcity of comprehensive investigations into the evolution of landscape ecological patterns under varying models of urban expansion; thus, it is imperative to analyze their underlying driving mechanisms.

China’s urbanization is notable for its rapid pace and extensive scale. The accelerated trajectory of metropolitan expansion in China commenced post-1990, particularly following the real estate reforms implemented in 1998. This growth of urban metropolitan areas has been accompanied by the development of commercial districts, residential neighborhoods, tourist attractions, subway systems, and major transportation hubs, resulting in a multifaceted new urban landscape (Cai et al., 2020). After 2010, with the ongoing enhancement of development models for satellite cities surrounding metropolises, the outward sprawl of these urban centers has significantly altered landscape ecological patterns (Yu, 2021), often impacting regional environments, climate change dynamics, mobility issues, and their interrelation with sustainability through processes such as urban expansion and land degradation or landscape transformation. In contrast to Western nations, the urban expansion arising from China’s metropolitan growth exhibits greater diversity in spatial manifestations and formation mechanisms (Oueslati et al., 2015; Rubiera et al., 2016). In major metropolitan regions like Beijing, Shanghai, and Hangzhou, much attention is directed towards analyzing overall spatial characteristics—including suburbanization trends, dual-center and sub-center structures within development zones (Wang et al., 2020; Gao et al., 2023). However, there remains a lack of awareness regarding the landscape ecological challenges posed by this urban expansion. This paper investigates the fundamental characteristics and patterns governing changes in landscape ecology during metropolitan growth phases to inform more targeted policy formulation aimed at optimizing regulatory frameworks.

Therefore, based on the basic geographic information data, land use data and urban landscape change data from 1990 to 2020, this paper applies the urban spatial expansion and landscape indices to systematically investigate the urban expansion pattern and its landscape ecological pattern driving type. The objectives of the study include: 1) To deeply analyze the characteristics of temporal dynamics and spatial changes of landscape ecological patterns based on the case of Hangzhou Metropolitan Area; 2) To identify the expansion modes of the metropolitan area, and the main types of driving forces in its landscape ecological patterns; and 3) to propose a regulatory strategy for the sustainable development of landscape ecology in the metropolitan area.

The influence of urban expansion on the transformation of landscape ecological patterns in the West is both cyclical and gradual (Chen, 2009). Worldwide, there are two predominant modes of urban spatial expansion: the extension model, exemplified by countries such as the United States, Canada, and Australia, which incrementally enhances urban spatial capacity around central areas; and the content model represented by Japan, South Korea, and Singapore that prioritizes vertical construction through taller buildings while optimizing underground space utilization (Liang, 2024). China’s strategy for urban spatial expansion has assimilated certain characteristics from Western nations but is significantly shaped by its administrative framework within a context defined by a large population relative to limited land resources and complex topography. Firstly, Hangzhou's limited land availability necessitates that construction indices prioritize new industrial spaces while public service facilities are adapted from existing city infrastructure during initial development phases. This requires optimization and adjustment of functional spaces within the urban fabric alongside strategic placement of significant projects and facilities. Secondly, for industries demanding substantial land use—such as key developments like Alibaba’s headquarters or G20 Convention Center—marginal expansions occur at the city’s periphery. Thirdly, the intricate interplay between topography, river networks, and transportation does not imply that all available spaces can be utilized for construction purposes. Given constraints posed by sites such as Liangzhu Ancient City World Heritage Site and Qiantang River Financial Harbor, establishing basic service facilities with seamless connectivity to central urban areas presents challenges; thus leapfrog enclave space expansion strategies are employed.

These three approaches collectively shape ongoing transformations in Hangzhou’s landscape pattern. Initially centered around West Lake during earlier phases of study development—the urban landscape pattern along Beijing-Hangzhou Grand Canal evolves through collaborative constructions parallel to this network encompassing blocks and industrial zones. Ultimately driven by leapfrog expansions along Beijing-Hangzhou Grand Canal results in an emergent urban landscape pattern characterized by a transition from point-based developments to comprehensive surface spread across Qiantang River while maintaining connections with Hangzhou’s original old city across the waterway. In this paper, we examine the phase transitions of landscape ecological patterns through the lens of urban land use structures to analyze the expansion patterns and driving forces behind urban landscape changes during the urbanization process. This significant endeavor to integrate urban ecological transformations with humanistic processes elucidates the interconnections among ecological, economic, and social elements within urban environments, thereby enhancing our understanding of the causal relationships underlying ecological changes in urban landscapes.

Firstly, this paper employs the Landscape Ecological Pattern Index (LEPI) to characterize and analyze the effects of urban expansion on the landscape ecological patterns of Hangzhou, China, from 1990 to 2020. It elucidates the typical driving models and formation mechanisms underlying these changes. Our findings are as follows: Between 1990 and 2020, Hangzhou’s area expanded from 463.05 km² to 1217.95 km², exhibiting a developmental trajectory characterized by “slow development-fast development-slow development.” The spatial transformation from center to periphery reveals a pattern marked by rapid fragmentation and renewal, filling and expansion, as well as plate expansion; spatially represented by swift fragmented renewal transitioning from central areas outward toward filling and plate expansion. This temporal-spatial evolution reflects a shift from industrialization towards an urban service-oriented economy underpinned by urban industrial transformation policies and supportive measures aimed at enhancing green spaces and living environments. The adjustment in urban developmental direction—encompassing comprehensive urban planning, revitalization of older districts, establishment of new industrial zones, and construction of residential areas—serves as a primary factor influencing alterations in the aforementioned landscape ecological patterns. Since 1990, changes in Hangzhou’s urban landscape have predominantly manifested through the conversion of natural or semi-natural landscapes such as arable land, green spaces, water bodies, and unused lands into residential areas for both urban-rural populations along with industrial sites and public service facilities (He et al., 2019). During the decade spanning from 2000 to 2010—stimulated by ongoing industrialization policies—the extent of urban land in Hangzhou peaked within nearly three decades with an increase of approximately 380.02 km² over ten years; this underscores the phased impact exerted by urban development policies. In the 1960s, Hangzhou was designated as a “comprehensive industrial city,” vigorously promoting industries such as iron production, cotton textiles manufacturing, and steamboat operations. Post-2000 saw Hangzhou adopt strategies emphasizing “industry revitalizing cities,” during which time secondary industry proportions stabilized around fifty percent; following this period after 2009 led to prioritizing service industries strategically. Throughout this decade marked by rapid large-scale expansions driven largely through extensive developments like numerous industrial parks alongside real estate booms fueled by substantial influxes of workers seeking residence or employment opportunities resulted in significant transformations within surrounding landscapes’ ecological frameworks. Post-2010 witnessed shifts influenced primarily due to financial crises wherein Hangzhou redefined its identity towards becoming a modern service-oriented tourism hub while systematically phasing out traditional industrial enterprises via outward relocations coupled with efforts focused on transforming aging infrastructures alongside developing adjacent tourist regions—a transition that also corresponded with declines in construction scale efficiency.

Secondly, the alterations in landscape ecological patterns induced by urban expansion in Hangzhou exhibited a transition from irregularity and fragmentation to clustering and functionalization, thereby validating the “diffusion-integration” hypothesis within the context of urban expansion (Dietzel et al., 2005). The spatial growth of Hangzhou was predominantly concentrated in its core urban area, constrained by natural landscapes such as West Lake and the Qiantang River water system. With evolving urban planning concepts, Hangzhou initiated the development of distinctive industrial parks in peripheral areas including Xiaoshan District, Yuhang District, Qiandao Lake, among other functional zones. Adjustments to land use structures were made during urban planning efforts to enhance both landscape and ecological functions within satellite cities, ultimately creating a cohesive functional landscape that aligns with Hangzhou’s main city. Evidently, this evolutionary process reflects a series of impacts stemming from shifts in policy regulation—from initial absence to refined governance—and from lackluster development planning towards systematic layered implementation. Urban expansion in Hangzhou encompassed three modes: edge expansion, infill expansion, and enclave expansion. Throughout these processes of growth, changes in landscape ecological patterns manifested diversely across four driving types: public service facility-driven; urban recreation development-driven; central business district-driven; and ecological landscape corridor-driven. These categories illustrate how policymakers facilitated industrial economic growth through constructing public service facilities and industrial parks while attracting substantial numbers of workers into residential areas— thereby stimulating real estate markets. In earlier phases, rapid urbanization resulted in fragmented landscapes characterized by intermingling rural-urban interfaces alongside emerging urban villages and industrial enclaves. Subsequently—following industry relocations—there has been an increase in green spaces and recreational lands which have contributed positively toward patch integrity while promoting more organized construction practices within the cityscape. In later stages marked by transitions from an industrial-centric model towards modernity, Hangzhou began vacating traditional industries while vigorously advancing sectors like modern services tourism along with rural economies—all complemented by developing ecological landscape corridors that spurred rapid economic progress for the city. This transformation journey also involved diverse strategies encompassing old city revitalization initiatives renovation projects targeting aging industrial zones as well as suburban expansions.

Ultimately, the transformations in Hangzhou’s urban landscape ecological patterns epitomize China’s urbanization trajectory, reflecting fundamental characteristics of land use structures and responses to landscape ecological changes during metropolitan expansion. This phenomenon bears resemblance to the late industrialization pathways observed in numerous developed nations. In terms of driving forces, these changes represent an inevitable outcome of transitioning from government-led urbanization to a model driven by a synergy between governmental and market forces. To achieve staged industrial development objectives, the government facilitated alterations in land use structures through initiatives such as constructing industrial parks, revitalizing older districts, and renewing aging industrial zones— thereby instigating shifts in landscape ecological patterns. Regarding driving forms within urban landscape ecological transformations prompted by urbanization, three distinct processes have been experienced sequentially. This progression reflects an evolution in the comprehensive power of urban expansion from weak to strong, small-scale to large-scale endeavors, and from singular influences to multifaceted dynamics. Throughout this process, capital investment and social engagement gradually converged with governmental oversight to foster overall transitions in urban land use and landscape ecological patterns—from fragmentation towards infill development and functional patching. Moreover, China’s urban policy framework alongside its methods for developing industrial parks as well as concepts surrounding green development have played pivotal roles; specifically indicating that changes within China's urban landscapes and ecological frameworks illustrate how various forces—including government entities, capital investments, societal contributions—have achieved equilibrium and compromise while pursuing their respective goals throughout the ongoing process of urbanization.

Considering the availability of statistical data, this paper only considers part of the administrative area of Hangzhou City, and does not take into account the impact of administrative division adjustment from 1990 to 2000. In the follow-up study, technical methods, such as gridding assignment, are adopted to deepen the study on the changes and effects of administrative division adjustment on urban landscape pattern, in order to understand more comprehensively the policy factors in the process of ecological sustainability of urban landscape in China.