Research On The Evolution Of The Fringe Belt Of The "City-in-Water" Type Ancient City In The Yellow River Flood Plain

The theory of urban fringe is an important part of Conzenian urban morphology.It is considered as an effective method to study the growth and change of urban physical morphology in the historical period and can provide effective guidance for urban landscape management.At present,the theory of urban fringe of Conzen has been widely applied in western cities,showing good applicability.However,there are few studies on the applicability of the theory to domestic cities,and there is a problem of "adaptability" in the process of studying the evolution of China's urban morphology.Under the background of new urbanization construction,it is necessary to explore the urban fringe belt theory of Conzen to provide guidance for the study of China's urban adaptation,urban renewal and the protection and development of historical landscape.The Yellow River Flood Plain is an important place for the development and evolution of ancient Chinese cities.Its long history of development and unique geographical environment have shaped its unique urban form.Huaiyang,a representative city in the ancient city of "city-in-water" in the Yellow River Flood Plain,is chosen as the research case.Based on the collection of historical maps and documents of Huaiyang,the evolution of urban morphology in Huaiyang is divided into stages.After that,the town plan and land use pattern of Huaiyang city in various periods are restored,the spatial distribution of its marginal zone is divided,and the causes and laws of the evolution of the marginal zone are explored.Finally,through the comparative study with the ancient city of Guide in Shangqiu,the characteristics and laws of the morphological evolution of the ancient city of "city-in-water" are summarized.In order to adapt to the unique situation of Chinese history and geography,the research paradigm of Conzen urban fringe belttheory has been reconstructed.This article mainly discusses the following:(1)The evolution process of Huaiyang city's morphology has experienced four types of morphology,which can be divided into "stable period","northern extension period" and "westward advance period".According to these three morphological periods,three layers of edge bands can be divided from inside to outside.The inner marginal zone has undergone hundreds of years of evolution from Tang and Song Dynasties to the founding of New China.The people of Huaiyang took a "digging low and raising high" response to the flood disaster,especially the flooding of the Yellow River,and formed the city dike and the lake around the city,which constituted the main part of the inner fringe of Huaiyang city today.The city dike and the lake around the city restricted the further development of Huaiyang ancient city from all directions.After the founding of new China,under the call of socialist industrialization construction,industrial construction began outside the northern around the city,forming a middle-edge zone along the main traffic road,which is composed of several industrial enterprises.After entering the reform and opening-up,in order to accommodate the urban population,environment,cultural relics protection and compact morphological characteristics,Xicheng District was taken as a new urban development area.The built-up area continued to move westward,taking Xihuang Avenue as the consolidation line,forming an outer fringe belt.(2)There are three common laws and characteristics in the historical evolution of the ancient city of "city-in-water" in the Yellow River Flood Plain.(1)Naturalness: The inner fringe belt of the ancient city of "city-in-water" is mainly composed of surrounding lakes.The reason for its formation is affected by flooding disasters mainly caused by the Yellow River floods.This is different from previous studies on the formation and causes of inner edge zones in cities such as Pingyao,Nanjing,Macao and Foshan.Previous studies have shown that the inner belt fringe of the city is mostly composed of open spaces,militarybuildings and religious sites.The reasons for its formation are mostly political,military,cultural and other factors.(2)Stability: the water fringe belt has strong stability.This water area that forms the fringe belt was mostly formed during the flood period in which the Yellow River flood to south.In ancient times,the ancient city of "city-in-water" used the method of "digging low and raising high" to cope with flood disasters,and used the method of building city embankments to resist floods.Therefore,the past dynasties paid more attention to the maintenance and improvement of city embankments,which enabled the water areas such as the lake around the city to exist for a long time and have strong stability.(3)the "axial belt" type development of the city: due to the restriction of the lake around the city,the "city-in-water" type city cannot realize the "concentric circle" type outward development of the general city,but can only first expand along the "axial belt" type outward development of the traffic trunk line,and finally realize the transfer of the city's center of gravity.(3)The study of Chinese cities by Conzen theory of urban fringe belt must be combined with the existing research paradigm of urban historical geography in China.This paper holds that the combination of Conzen theory of urban fringe and "Hou Renzhi's working method" is the way to realize the "Sinicization" of the theory.Influenced by the Yellow River,the ancient city of the Yellow River Flood Plain has seen such phenomena as the annihilation of the city,the relocation of the city site,the change of form,the rise and fall of the city,etc.Before drawing lessons from the urban form theory and the fringe belt theory of Conzen,we should first,in accordance with the research dimension of "Hou Renzhi's Work Method",focus on recovering the evolution process of the city from the changes of the city site and the formation of the city's appearance to lay a foundation for the further study of Conzen urban form theory.