空间基因视角下揭阳古城公共空间形态与活态保护OACHSSCD

Jieyang Ancient Town is facing multiple challenges,such as the destruction of water systems,the fragmentation of street and alley networks,and the continuous loss of local living culture.Most existing studies focus on qualitative descriptions of water system landscapes,individual buildings,and folk customs.However,the lack of a systematic quantitative analysis on the morphological characteristics of public spaces in the ancient town makes it difficult to develop refined conservation plans that are grounded in the underlying spatial logic.In this study,a comprehensive analysis incorporating living conservation strategies in the 1.25 km2 core historical district of Jieyang Ancient Town,a typical water town in Chaoshan,was conducted by applying the theory of spatial genes.It aimed to identify the unique spatial gene lineage of Jieyang Ancient Town,elucidate the mechanisms governing the formation and degradation of public spaces under the influence of the water system,construct a unique hierarchical dynamic renewal system for Chaoshan water towns,fill the gap in quantitative research on public spaces in county-level water towns in Lingnan,and provide a reference for the renewal of similar river-network-based historical towns. Based on a three-tiered analytical framework composed of macro-ecology,the meso-built environment,and micro-humanity,this empirical study was conducted using a comprehensive approach that combines historical geographical map analysis,field surveying,and quantitative spatial comparison analysis.Field survey data from 2018 was compared with historical maps from 1945,thus enabling an estimate of spatial decay indicators.Furthermore,the spatial genes of the ancient town were analyzed through its landscape foundation,water system,fishbone-like streets and alleys,clan settlements,and multi-tiered cultural carriers.The morphological differences between Jieyang and Jiangnan water towns were quantified,and the inherent patterns in which Feng Shui urban planning,clan ritual systems,and the integration of waterfront commerce and trade collectively shaped the urban space were recognized. The results indicated that Jieyang Ancient Town exhibits a three-tiered,nested spatial genetic system.At the macro level,the ancient town's foundation represents gourd-shaped Feng Shui urban planning formed by"three mountains and two rivers",while a rigid ecological framework was formed by the dual-layered defensive system and multiple visual corridors.At the meso-level,driven by the high-density"three cellars"water systems,an embedding texture of T-shaped fishbone-like streets and clan settlements was developed,in which the historical water coverage rate reached 18.7％and the proportion of T-junctions accounted for 67.2％.This configuration differs significantly from the orderly,grid-like water system of the Jiangnan region and embodies a clan-led spatial coupling logic:"water determines roads,roads determine settlements,and settlements are paired with ancestral halls".At the micro level,a cultural spatial network with the coexistence of ancestral worship,commerce,and folk customs is formed,carrying the living transmission of the intangible cultural heritage of Chaoshan.A quantitative assessment of the current situation revealed the multi-level degradation of the spatial genes of the ancient town.The landfill rate of historical waterways is 43.7％,the topological continuity of the road network has decreased by 38％,and the preservation rate of traditional settlement fabric is less than 42％.Meanwhile,issues such as the disruption of landscape visual corridors,the loss of traditional construction techniques,the disappearance of local businesses,the migration of original residents,and the reduction of spaces for folk activities are evident.At the meso-level,the fragmentation of the water-road-settlement texture fragmentation is the core cause of the morphological decline of the ancient town. Based on the conservation logic of"gene identification-morphological diagnosis-tiered restoration-long-term management",an integrated living conservation strategy was proposed in this study.At the macro level,the protection boundaries for the landscape were established clearly,accompanied by dredging and restoration of the"three cellars"water system and Feng Shui ponds.Furthermore,the original ecological pattern of the water town was reshaped.At the meso-level,an"acupuncture-style"micro-renewal approach was adopted to restore the original scale and connectivity of streets and alleys,regulate the settlement texture of the community,and restore the characteristics of arcaded streets and alleys.At the micro level,a digital platform for transmitting traditional construction techniques was built,and a positive and negative list of business activities was created to revitalize local commercial and intangible cultural heritage spaces.A community-based co-governance deliberation model and a digital twin monitoring platform for the ancient town were established through long-term mechanisms to achieve full-cycle dynamic management and control. This study refined the technical approach for identifying the spatial genes of water towns,established a quantitative analysis framework for public spaces in Chaoshan water towns,and overcame the limitations of static preservation in traditional landscape restoration.In this way,a balance among spatial authenticity,the continued presence of indigenous residents,and the coordinated development of culture and tourism was achieved.The tiered renewal model not only provides technical support for the implementation of the preservation plan for Jieyang Ancient Town but also offers replicable theoretical and practical references for the refined living renewal of similar river-network-based Lingnan historical towns in South China.