Investigating the potential historic conservation area in China: a case study on 11 old colonial cities Investigating the potential historic conservation area in China: a case study on 11 old colonial...
Wang, Yang; Matsumoto, Kunihiko; Wang, Rui; Zhou, Weinan; Sawaki, Masanori
JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING https://doi.org/10.1080/13467581.2023.2182644 URBAN PLANNING AND DESIGN Investigating the potential historic conservation area in China: a case study on 11 old colonial cities a b a c b Yang Wang , Kunihiko Matsumoto , Rui Wang , Weinan Zhou and Masanori Sawaki a b College of Architecture, Dalian Minzu University, Dalian, Liaoning, China; Graduate School of Engineering, Osaka University, Osaka, Japan; College of Architectural Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, China ABSTRACT ARTICLE HISTORY Received 29 November 2022 The designation of historic conservation areas (DHCAs) from the cities classified as Accepted 16 February 2023 “National Famous Historical and Cultural City” (NFHC-city) is the key tool for maintaining large-scale historic environments, wherein the boundaries are blurred because of redeve- KEYWORDS lopment. Therefore, exploring potential historic conservation area is fundamentally impor- Concession; urban tant. In this study, we examined historic urban areas in 11 old colonial cities (concessions morphology; heritage and leased territories) to determine the potential historic conservation areas (P-HCAs). Our conservation; historic district; results suggest that P-HCAs are characterized by relatively small size, minimal residential heritage management use, and irregular morphological boundaries, except in some non-NFHC-cities, where P-HCAs are located adjacent to officially protected public and commercial buildings. The DHCA boundaries and extent of urban development influence the storage of P-HCA. The approach and method proposed in this study not only provide reference for the con- servation and replenishment of the historic districts in China, but are also applicable for other countries. CONTACT Weinan Zhou, email@example.com College of Architectural Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the Architectural Institute of Japan, Architectural Institute of Korea and Architectural Society of China. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 2 Y. WANG ET AL. 1. Introduction selected for protection because of vague indicators such as style. Even if cities meet the quantitative indi- th Since the mid-20 century, there has been a significant cators such as area, many of them face the problem of increase in the global interest toward heritage conser- large-scale demolition and reconstruction of historic vation and management; this interest is generally districts (Chan and Ma 2004). For example, although linked to the understanding of heritage areas and Shanghai was recognized as an NFHC-city in 1986 and novel approaches for managing the changes in the a representative DHCA was selected; many Shikumen historic environment (Chen, Ludwig, and Sykes 2021). Lilong neighborhoods representing the old cultural The Chinese historical heritage conservation system, DNA of Shanghai were not granted the DHCA status which consists of designation of historic conservation because Shanghai has many Shikumen residential area (DHCA ) from the city designated as “National neighborhoods. Because the selection of DHCA is strict Famous Historical and Cultural City” (NFHC-city ), is and cumbersome, Shanghai cannot designate all one of the most effective methods to maintain large- Shikumen Lilong neighborhoods as DHCA, and they scale historical environments. With rapid urbanization, have been demolished under the pressure of urban some cities in China have deliberately selected a small renewal (Liu 2016). Therefore, in the context of the number of historic districts to meet the requirements massive disappearance of historic urban areas in of the NFHC-city policy to obtain more land for con- China, it is difficult to effectively protect the historic struction, whereas some districts have not been The historic area reviewed and officially approved by the Provincial People’s Government. The city that is rich in cultural relics and possess significant historical value or revolutionary significance simultaneously is approved by the State Council of China as an authoritative historic city. JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 3 urban areas by relying only on the existing DHCA and Guangzhou, based on the theory of spatial syntax (Huang and Ji 2019; Wu, Fang, and Shi 2019). classification criteria; it is necessary to assess and inte- Moreover, Liu et al. (2017) argued that the conserva- grate potential historic conservation areas (P-HCAs ) tion and development of P-HCA should involve into the historic conservation system (Cai, Liu, and a highly diverse evaluation mechanism and an opera- Xin 2021). However, because the boundaries of tional mechanism of government–enterprise coopera- P-HCAs are unclear, it is critical to determine the tion to achieve the purpose of historical continuity and stock of P-HCAs and develop novel conservation stra- economic value creation. Simultaneously, some stu- tegies based on the characteristics of areas using quan- dies explored the effects of preservation and develop- titative analysis methods. ment of P-HCAs in specific cities from the perspectives Notably, P-HCA is not an internationally used term, of continuation of the neighborhood commercial func- and in the mainstream Western context of historic tion (Xia 2021) and neighborhood texture preservation district conservation, it was the Declaration of (Wang et al. 2017). In addition, Yang (2022) pointed out Amsterdam of 1975 that attracted attention to the that the P-HCA of the non-NFHC-city of Jiangyin conservation of historic districts. In the Western heri- should not only focus on the physical conservation, tage conservation system, historic districts are often but also the formulation of policies, such as restoration considered as a whole, and in urban development, of characteristic cultural activities, preservation of ori- new cities are often built in the suburbs to preserve ginal living paradigms of residents, and development and cautiously renew the buildings of the old cities. of guidelines for renovation of residential houses. Therefore, no officially recognized small conservation However, no research has analyzed the spatial inven- areas or neighborhoods are omitted by heritage laws tory and morphological characteristics of the neigh- (Rodwell 2003). Studies on historic districts in Western borhoods of P-HCAs. countries frequently focus on urban morphological It is highly appropriate to explore this topic in the features (Colaninno, Roca, and Pfeffer 2011), building context of concessions and leased territories in China, renovation restrictions and guidance (Yukinobu 2000), which began in the 1860s with the conclusion of urban landscape formation (Zeayter and Mansour numerous territorial leases and treaties of commerce; 2018), and multidisciplinary connections in the conser- the Qing dynasty leased land along the eastern coast vation of historic district landscapes (Fiorino and Pirinu of China to the British, French, and Japanese govern- 2017). According to Cai, Liu, and Xin (2021), P-HCA is ments. We further call this period the “colonial era. ” a concept based on a unique historic district neighbor- These foreign colonial cities were divided into “conces- hood preservation policy system in China, which can sion” and “leased territories.” Concessions refer to the be defined as “old neighborhoods that are not desig- leasing of a portion of a governed area in a city to nated as DHCA by the government but have certain a certain country, and a city may have multiple con- characteristics of street style and cultural heritage”. cessions, such as Shanghai and Tianjin, which are They have the following three characteristics: not offi - representative of such cities. Leased territories refer cially recognized, unclear boundaries, and a long- to the leasing of a large area of a territory to a certain standing social community network. country, accompanied by the urban planning of the In contrast, research on historic districts in China has suzerain state to form a larger modern city, such as majorly focused on DHCA. Most of the current studies Qingdao and Dalian. Although these urban legacies on DHCA in China have focused on theoretical are not rooted in the local Chinese culture, they are improvements in conservation. When demonstrating a relevant part of the urban and architectural heritage the setting process and operation mechanism of the because they were formed during the “colonial era” NFHC-city conservation system, Zhang (2012) referred and therefore have distinctive historical value. In the to the problems posed by insufficient restrictions on 1980s, with the economic development in China, the urban renewal in historic districts and the preservation pressure of the concessions and leased territories, of historic districts via redevelopment. Ruan and Sun which were the pioneers of the economic develop- (2001) proposed an approach for setting the conserva- ment, gradually increased, and large areas of the con- tion scope in terms of landscape management and cessions and leased territories were demolished. functional use guidance of the neighborhood. In addi- However, these colonial cities still retain some historic tion, among the studies that examined the morpholo- districts that are not designated as DHCA owing to the gical feature characteristics of historic urban areas in China, some highlighted the characteristics of Suzhou large area of historic urban area, and are therefore 3 2 The criteria for modern historic conservation area represents the district with area not less than 0.01 km and the architecture in concessional period occupying over 60% of the total district area. The area that fits the criteria of historic conservation area, while not recognized as historic conservation area. The opening and revocation of concessions changed from city to city, with the British government opening the first concession in Shanghai in 1842, while most cities had concessions opened in the 1860s and 1890s. Most of the concessions were revoked in the 1940s, although some cities revoked certain concessions as early as 1917. 4 Y. WANG ET AL. suitable as a sample for this study to examine the stock In Step 2, we focused on historical urban areas where P-HCAs may exist by consulting the “city status and spatial characteristics of P-HCA. map” in the “city master plan” of each municipality, For modern concessions, significant research has determined the boundaries of land allocation units been conducted on the history of related urban devel- and the construction dates of buildings in the neigh- opment and formation. Jiang and Fujikawa (2013) illu- borhoods, and then extracted the neighborhoods with strated the formation process of the road network of historical buildings from the “colonial era.” Based on street trees in the city of Qingdao. For the Tianjin this information, we classified the P-HCAs, and based Concession, Liu and Fujikawa (2015) addressed the on the quantified criteria in the DHCAs selection cri- formation process of the British Concession. teria, we established the following principles for the Moreover, Wang, Matsumoto, and Sawaki (2019) classification: (1) Adjacent neighborhoods with historic reviewed the impact of commercial renovation of his- buildings or land allocation units can form toric buildings on streetscape preservation and high- a neighborhood (Figure 2). (2) The district with area lighted the problems of the existing renovation not less than 0.01 km and the architecture in conces- approval criteria, focusing on the British Concession sional period occupying over 60% of the total district in Tianjin, which was selected as a DHCA. However, area. (3) Derive the blocks with the largest possible the above-mentioned studies did not discuss the area. As shown in Figure 3, we demonstrated the spe- P-HCA of modern concessions. Moreover, in the analy- cific steps of delineating P-HCAs using Dalian as an sis of the morphological and scaling characteristics of example. The reason for choosing this example is the a region, these studies did not consider the old neigh- relatively complex morphology of Dalian neighbor- borhoods of the tenement cities not listed in the con- hoods and the high abundance of building types in servation list. To the best of our knowledge, this is the the neighborhoods. first study to fill this gap by examining the potential In Step 3, after capturing the stock of P-HCAs via Step historic conservation area in China. 2, we divided the target cities into three categories This study focused on historic districts formed during based on two indicators–P-HCAs and DHCAs–and ana- the “colonial era” and used the quantifiable criteria of lyzed the reasons for the formation of each category. neighborhood “area” and “area ratio of historic build- Finally, after deriving the P-HCAs, we analyzed the ings to the entire site” in the DHCA designation to original functions and morphological characteristics of determine the boundaries and stock of P-HCAs. The each block in the district. The architectural style and cities were also classified by stocks of P-HCAs and planning in the P-HCA was determined using the DHCAs. In addition, this study aimed to analyze the Street View of Baidu Maps for determining original func- characteristics of the P-HCA in each area, including ori- tions of the historical architecture. To understand the ginal functions of the architecture, and morphological P-HCA characteristics of Shanghai and Dalian within the characteristics of each block in the district. This study remains of historical buildings, we referred to the books can serve as a basis for the future conservation of “History guide map of Shanghai” and “History guide unclassified historic districts and serve as a novel map of Dalian and Lvshun,” to learn the original building approach toward redefining their scope of preservation. functions of the P-HCAs. For the morphological charac- teristics of the neighborhoods, we typified them with the morphology of the borderline. 2. Methodology To capture the stock of P-HCAs and to elucidate the 3. Background of case studies characteristics of these neighborhoods, this study had three main steps: (1) determine the range of historic 3.1. Division of concessions and leased territories urban areas where P-HCAs may exist; (2) calculate the and designation of historic and cultural cities stock of P-HCAs; and (3) classify the object cities based Figure 4 demonstrates the location of the target cities on P-HCAs and DHCAs (Figure 1). Based on these steps, and the division of the concessions and leased terri- the characteristics of the P-HCAs were finally analyzed. tories, as well as the conditions required for being In the first step, to determine the extent of historic designated as an NFHC-city. Five cities (Guangzhou, urban areas where P-HCAs may be present, we con- Shanghai, Tianjin, Wuhan, and Xiamen), out of the firmed the boundaries of the historic urban areas in the total 11 cities considered in this study, used conces- selected cities by examining each historical map of sions occupied by the United Kingdom, Japan, or the each old colonial cities. To define the boundaries for United States of America. Notably, the six cities the designation of DHCAs, we examined the protection Qingdao, Harbin, Changchun, Shenyang, Dalian, and plan of the historical sites of the selected cities and Anshan used to be concessions that once belonged to then removed the DHCA boundaries from the historic Germany, Russia, or Japan. In terms of the conditions urban areas. Finally, a historic urban area with the possible presence of P-HCAs was obtained. for being designated as NFHCcities, eight cities JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 5 Figure 1. Research flow chart. Figure 2. Principle of P-HCA classification. Figure 3. A case study of analysis process of P-HCAs (Dalian city). 6 Y. WANG ET AL. Figure 4. Location of the target cities, division of the concessions and leased territories, and boundary of the city in the National Famous Historical and Cultural City (NFHC-city) Conservation System. (Guangzhou, Shanghai, Tianjin, Wuhan, Qingdao, features of the region, and then carry out guaranteed Harbin, Changchun, and Shenyang) were considered conservation. Some cities selected their DHCAs based on the local regulations. For example, Xiamen has as NFHC-cities. The cities not considered as NFHC-cities a city-level designated DHCA although it is not an were Dalian, Anshan, and Xiamen. NFHC-city. (Source: Figure of Tianjin: https://app.cseas.kyoto-u. Table 1 presents the number and area of DHCAs and ac.jp/infolib/cont/01/G0000022PPC/000/061/ 000061647.jpg; Figure of Dalian: https://app.cseas. the ratio of DHCAs in the historic urban area. A total of kyoto-u.ac.jp/infolib/cont/01/G0000022PPC/000/063/ 43 DHCAs were identified from eight NFHC-cities and 000063897.jpg; Figure of Shanghai: https://rmda.kulib. the city-level historic urban areas of Xiamen, approxi- kyoto-u.ac.jp/item/rb00031383#?c=0&m=0&s=0&cv= mately half of which belonged to Qingdao and Tianjin. 0&r=0&xywh=−15%2C124%2C4934%2C1925) In terms of area, Shanghai and Qingdao cover an area of over 10 km , whereas Tianjin and Changchun cover an area of 5 km . In contrast, Harbin and Shenyang, as 3.2. Stock of Designated Historic Conservation well as Guangzhou, Wuhan, and Xiamen, which have Area (DHCA) and categories of designation in the smaller historic urban areas, cover an area of only target city 3 km . In terms of the proportion of the DHCA in the historic urban area, the boundary of the DHCA in After being designated as an NFHC-city, the local municipal government would be obliged to select Qingdao, Guangzhou, and Xiamen coincides with that one or more DHCAs that would represent the historical of the historic urban area, thus indicating a proportion Table 1. Number and area of designated historic conservation area (DHCA), and the ratio of DHCA in the historic urban area. DHCA 2 2 Division of city City name Area of HUA (km ) Number Area (km ) Proportion in HUA (%) NFHC-city Shanghai 36.14 5 10.153 28.1 Qingdao 14.66 12 14.66 100.0 Tianjin 18.11 11 7.167 39.6 Wuhan 2.11 5 1.237 58.6 Guangzhou 0.24 1 0.24 100.0 Harbin 30.37 5 2.908 9.6 Changchun 51.33 2 6.46 12.6 Shenyang 14.52 1 1.04 7.2 Non-NFHC-city Xiamen 2.08 2 2.08 100.0 HUA: historic urban area; NFHC-city: National Famous Historical and Cultural City JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 7 Table 2. Categories for designation of historic conservation area (DHCA) (n = 43). The categories for designation of DHCA Modern neighborhood with typical architectural styles Number of DHCA in a target Individual Collective Revolutionary Waterfront City name city Public Commercial residences residences heritage landscape Shanghai 5 3 3 2 3 – – Qingdao 12 2 2 6 3 – – Tianjin 11 3 5 5 3 – 1 Wuhan 5 2 3 – 2 1 – Guangzhou 1 1 – – – – – Harbin 5 2 1 1 1 – – Changchun 2 2 – – – – – Shenyang 1 – 1 – – – – Xiamen 2 1 1 1 – – – Total 43 16 16 15 12 1 1 of 100%. Wuhan accounts for 58% of the total area, Shanghai covered the largest total area and the high- est composition ratio in the historic urban area, along whereas other cities account for less than 50% of the with a relatively large number of P-HCAs. In contrast, total area. the P-HCAs in Tianjin, Wuhan, Changchun, and Table 2 lists the categories for the designation of the Shenyang were 0.4 km , and the proportion in the DHCAs. In terms of the categories, there were 41 mod- historic urban areas was below 5%. ern-type DHCAs having “modern neighborhood, with Regarding the reasons for the impact of P-HCA typical architectural styles,” and one for each of the stocks, in Tianjin and Wuhan, in addition to urban “revolutionary heritage type DHCA” and the “water- development, there was already a high number of front landscape type DHCA.” Among the categories of DHCAs, which resulted in a smaller number of P-HCAs. the “modern-type DHCA,” except the public and com- The smallest area of P-HCA in Wuhan corresponded to mercial (business-oriented) buildings (16 each), most its small historic urban area. Changchun and Shenyang blocks are considered to be residential blocks (15 indi- lost large historic urban areas due to rapid urban devel- vidual and 12 collective residences) because they are opment. These heavy industrial cities in Northeast typical of architectural style. China have already begun urban renewal (with the help of large state-owned enterprises) at the beginning of the planned economy era since the 1950s. 4. Results 4.1. Stock of Potential Historic Conservation Area 4.1.2. Type B: only Potential Historic Conservation (P-HCA), Classification of Target Cities based on Area (P-HCA) P-HCA, and Designation of Historic Conservation In the cities belonging to this type, the DHCA area in Area (DHCA) Anshan was only 0.158 km , but Dalian had a larger The locations of DHCAs and P-HCAs in the target cities P-HCA of 1.55 km . This may be because only a part of are shown in Figure 5. The areas of the P-HCAs in the the city buildings was officially protected. Note that target cities are shown in Table 3. All the target cities, the presence of several military-owned buildings may except for Qingdao, Xiamen, Guangzhou, and have inhibited the rapid development of the city. Changchun, have P-HCA stocks. Based on the presence/absence of DHCA and P-HCA 4.1.3. Type C: only Designated Historic in a city, we categorized the cities into three groups: Conservation Area (DHCA) “Type A: DHCA and P-HCA” (Shanghai, Tianjin, Wuhan, The reasons for the non-existence of P-HCA in the cities Shenyang, and Changchun), “Type B: Only P-HCA” belonging to this type are simple and clear. Qingdao (Dalian and Anshan), and “Type C: Only DHCA” set the boundary of the urban historic area as the (Qingdao, Guangzhou, Harbin, and Xiamen) conservation boundary of the urban historical environ- (Figure 6). From the aspect of the P-HCA area and the ment aiming at initial conservation of city. Guangzhou proportion of the P-HCA in the historic urban area, the characteristics of the three types of cities were ana- and Xiamen contained comparatively smaller conces- lyzed as follows: sion areas; for these cities, we could achieve the boundary of the entire historic urban area, according to the conservation boundary of the DHCA. For Harbin, 4.1.1. Type A: Designated Historic Conservation similar to the Changchun and Shenyang cities (among Area (DHCA) and Potential Historic Conservation the Type-A cities), the historic urban area outside the Area (P-HCA) DHCA disappeared owing to the ongoing urban devel- In this type, both the DHCA and P-HCA co-existed in the historic urban area. In our study, the DHCA in opment since the 1950s. 8 Y. WANG ET AL. Figure 5. Locations of the designated historic conservation area (DHCA) and potential historic conservation area (P-HCA) in the target cities selected in this study. 4.2. Characterization of Potential Historic in the target cities. A total of 65 P-HCAs were con- Conservation Area (P-HCA) firmed in the target cities, including 34 in Shanghai and 14 in Dalian. The number of P-HCAs in other cities Figures 7 and 8 clearly illustrate the area, original was less than 10. functions of architecture, and morphology of blocks JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 9 Table 3. Area of potential historic conservation area (P-HCA) in the target cities. DHCA P-HCA 2 2 2 Division of city City name Area of HUA (km ) Area (km ) Proportion in HUA (%) Area (km ) Proportion in HUA (%) NFHC-city Shanghai 36.14 10.153 28.1 3.483 9.6 Qingdao 14.66 14.66 100.0 – – Tianjin 18.11 7.167 39.6 0.315 1.7 Wuhan 2.11 1.237 58.6 0.069 3.3 Guangzhou 0.24 0.24 100.0 – – Harbin 30.37 2.908 9.6 – – Changchun 51.33 6.46 12.6 0.167 0.3 Shenyang 14.52 1.04 7.2 0.135 0.9 Non-NFHC-city Xiamen 2.08 2.08 100.0 – – Dalian 31.5 – – 1.559 4.9 Anshan 3.48 – – 0.158 4.5 HUA: historic urban area; NFHC-city: National Famous Historical and Cultural City Figure 6. Types of cities based on designated historic conservation area (DHCA) and potential historic conservation area (P-HCA). 4.2.1. Characteristics of the area of Potential Considering the proportion of residential build- Historic Conservation Area (P-HCA) ings to the total area of the site (residential rate) as In terms of the area of a single P-HCA, more than an indicator, the proportion of residential buildings 90% of the blocks had P-HCA less than 0.2 km . In in most blocks was larger than 60% (Figure 10). terms of the DHCA, 70% of the blocks had areas Such blocks can be defined as residential P-HCAs. larger than 0.2 km (Figure 9). Based on such char- Among the target cities, Shanghai had the largest acteristics, in the future, for conservation, it will be number of residential P-HCA (n = 34) and collective more effective to classify the adjacent small P-HCAs residences, with an intensive living density; Li- into a group, rather than planning the conservation Nong accounted for the largest percentage. If the of only a single P-HCA. government considers preserving these buildings in the future, improving the living environment will be a major issue. In addition, in terms of the 4.2.2. Initial functions of architecture in Potential two indicators of “residential rate” and “area,” Historic Conservation Area (P-HCA) a vast majority of blocks were residential P-HCAs From the initial functions of architecture, P-HCAs having an area of less than 0.1 km (Figure 11). can be categorized into six types, among which We observed a few P-HCAs having lower resi- historical architecture can be classified into busi- dential rates; most of these P-HCAs were concen- ness, public and industrial buildings, and individual trated in Dalian (6 P-HCAs). These P-HCAs and collective residences. In this study, the other contained a large number of public and commer- non-historical architectures were classified into one category. cial architectural buildings that were officially 10 Y. WANG ET AL. Figure 7. Initial functions of potential historic conservation area (P-HCA) in non-national famous historical and cultural city (non- NFHC-city). protected, and such blocks were often designated association with the surrounding blocks were also con- as DHCAs in the NFHC. sidered. In general, the boundary between the Finally, several non-historical architectural buildings I-shaped P-HCA and the ordinary block was clear. The also existed in the P-HCA, most of which exhibited the ordinary block formed a street corner inside the partial renovation pattern that was generally seen L-shaped P-HCA, whereas the U + L-shaped P-HCA before 2000. had the characteristics of an L-shaped P-HCA and even wrapped a part of the ordinary street into its interior. 4.2.3. Morphology of block in Potential Historic The correlations between the morphology of the Conservation Area (P-HCA) block and the block area are listed in Table 4. Based on the morphology of the block, the P-HCAs Almost all the blocks having areas less than were divided into three types: I, L, and U + L. The 0.05 km were I-type and L-type blocks, and the complexity of their shapes and the closeness of their JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 11 Figure 8. Initial functions of potential historic conservation area (P-HCA) in national famous historical and cultural city (NFHC-city). ratio of I blocks to the blocks having areas less than 0.1 km , the ratio of the U + L blocks than 0.02 km was close to 70%. Among the blocks exceeded 60%, i.e., if the P-HCA was large, it was having an area of 0.05–0.1 km , L-shaped blocks easy to portray a complex morphology. accounted for the vast majority, with a ratio of The building function and ownership of colonial 72.7%. For the blocks having an area of more cities are generally complex; for example, during 12 Y. WANG ET AL. Figure 9. Area comparison of designated historic conservation area (DHCA) and potential historic conservation area (P-HCA). Figure 10. Residential rate of potential historic conservation area (P-HCA) in target cities. Figure 11. Characteristics of the potential historic conservation area (P-HCA), based on the indicators of the residential rate and area. Table 4. Correlation between the morphology of block and block area. Area/Type I-type L-type U + L-type 0.01–0.02 km (n = 13) 69.2% 30.8% 0 0.02–0.05 km (n = 22) 50.0% 45.5% 4.5% 0.05–0.1 km (n = 11) 9.1% 72.7% 18.2% 0.1–0.2 km (n = 13) 7.7% 30.8% 61.5% > 0.2 km (n = 6) 0 33.3% 66.7% p = 0.000 JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 13 Figure 12. Model diagram and a case study of the relationship between potential historic conservation area (P-HCA) morphology and urban development. urban development, large areas cannot be con- these cities and the intensity of urban development structed in a short time. Therefore, as shown in were the main factors that affected the P-HCA storage Figure 12, when the blocks that were not devel- in these regions. Additionally, in these cities, the oped were divided into P-HCAs, the complex mor- P-HCAs disappeared with further development. phology of the study area could be easily In this study, we focused on individual P-HCAs, most portrayed. of which were characterized by a relatively small size, residential use, and irregular morphological bound- aries. However, in non-NFHC-cities, such as Dalian, we 5. Conclusions observed that P-HCAs were mainly composed of sev- eral public and commercial officially protected archi- This study elucidated the stocks and characteristics of tecture buildings. DHCAs and P-HCAs in China’s old colonial cities. In Based on the above conclusions, if the P-HCA in NFHC-cities, the government has set a DHCA to protect a city is also regarded as a historic area that should the historical environment, based on the public, com- be conserved in the future, the following four sugges- mercial, and residential use. However, owing to the tions are meaningful: differences in the size of the historic urban area in each city and the government’s principles for setting (1) Because most of the blocks are not large DHCA boundaries, the DHCA in each city and its pro- while planning conservation, several adjacent portion in the historic urban area are different. blocks can be regarded as a unified planning Among all the cities considered in this study, the group. Simultaneously, new or redeveloped stock of P-HCA has been confirmed in both the NFHC- blocks between different P-HCAs should be cities (Shanghai, Tianjin, Wuhan, Shenyang, and included in the scope of conservation, and Changchun) and non-NFHC-cities (Dalian and their appearance, height, and usage should Anshan), with the only exception being Qingdao, be regulated and guided for them to be in Guangzhou, Harbin, and Xiamen. Therefore, based on agreement with the P-HCAs. whether a city has DHCA and P-HCA, we considered (2) Because most buildings in the blocks are used the following three types: “Type A: DHCA+P-HCA,” for housing, improving the quality of residence “Type B: Only DHCA,” and “Type C: Only P-HCA.” The should be considered an important issue in storage of P-HCA in most cities was small, except in future conservation plans. Shanghai and Dalian. The DHCA boundary setting of 14 Y. WANG ET AL. (3) In the case of non-NFHCcities, such as Dalian, ORCID some P-HCAs contained a large number of Weinan Zhou http://orcid.org/0000-0001-7726-642X officially protected architectural sites. The historical area formed by this type of histor- ical architecture has conservation value; References therefore, such blocks can be identified as Cai, X., C. Liu, and S. Xin. 2021. “A Review of the Comparative DHCA in local city-level protection policies. Study of Historical Blocks and Nonprotected Histori-cal (4) Because many P-HCAs have an irregular morphol- Blocks.” Architecture & Culture 03 (68): 182–184. ogy, they are more closely related to surrounding Chan, W., and S. Ma. 2004. “Heritage Preservation and blocks; notably, some developed blocks may also Sustainability of China’s Development.” Sustainable be surrounded by P-HCA. Therefore, when for- Development 31 (November 2003): 15–31. Chen, F., C. Ludwig, and O. Sykes. 2021. “Heritage mulating conservation plans, significant attention Conservation through Planning: A Comparison of Policies should be paid to the relationship between the and Principles in England and China.” Planning Practice two types of blocks. Novel ideas need to be and Research 36 (5): 578–601. doi:10.1080/02697459. implemented in such cases, e.g., setting up 2020.1752472. pocket parks in enclosed areas to serve as visual Colaninno, N., J. Roca, and K. Pfeffer. 2011. An Automatic buffers or strengthening the townscape control Classification of Urban Texture: Form and Compactness of Morphological Homogeneous Structures in Barcelona. of general streets at the border of P-HCA. Barcelona: 51st Congress of the European Regional Science Association. The methodology and findings of this study provided Fiorino, D. R., and A. Pirinu. 2017. “Interdisciplinary new insights into the protection of historic districts in Contribution to the Protection Plan of the Fortified Old the Chinese conservation system, i.e., “National Town of Cagliari (Italy).” International Journal of Heritage Architecture: Studies, Repairs and Maintence 1 (2): 163–174. Famous Historical and Cultural City.” The protection doi:10.2495/ha-v1-n2-163-174. of historic districts can not only be limited to the Huang, K., and M. Ji. 2019. “Research Onthe Sustanable level of historic and cultural districts, but also for Conservation of Urban Historic Enviroment Base on other historic districts. To achieve this, a flexible criter- Spase Syntax : A Case Study on Xiguan Historic Area in ion level for the identification of potential historic Guangzhou.” New Architecture 06: 21–25. conservation area (P-HCA) can be created to complete Jiang, B., and M. Fujikawa. 2013. “The Formation Process of the policy framework for the protection of historic Qingdao’s TREE-LINED Streets (1891-1945).” Journal of Architecture and Planning (Transactions of AIJ) 78 (693): districts. Meanwhile, the criteria for designating and 2321–2328. doi:10.3130/aija.78.2321. recognizing P-HCAs are not entirely consistent with Liu, G. 2016. “Reflection on Shanghai Shikumen Lilong those for DHCAs, as more P-HCAs could be identified Rehabilitation.” HERITAGE ARCHITECTURE 4: 1–11. if the proportion of historic buildings in the area is Liu, Y., and M. Fujikawa. 2015. “The Development Process of reduced. Therefore, a more lenient and flexible desig- the Original British Concession in Tianjin, China.” Journal of nation criteria might be more beneficial to the conser- Architecture and Planning (Transactions of AIJ) 80 (712): 1285–1294. doi:10.3130/aija.80.1285. vation of the historic environment. Liu, J., W. Huang, L. Wang, N. Shi, J. Yang, and S. Wang. 2017. Although this study provided novel insights, it has “Organic Renewal of Urban NON-PROTECTION Blocks.” some limitations. First, it primarily focused on the pol- CITY PLANNING REVIEW 03: 94–98. icy of historic city protection and did not compare the Rodwell, D. 2003. “Sustainability and the Holistic Approach to identification of historic districts under other policies; the Conservation of Historic Cities.” Journal of Architectural secondly, this study focused on the inventory and Conservation 9 (1): 58–73. doi:10.1080/13556207.2003. classification of districts, but did not assess the heri- Ruan, Y., and M. Sun. 2001. “Some Problems in the Protection tage value of potential historic districts. Hence, it calls of Chinese Historic Conservation Area.” City Planning for future investigations wherein a systematic heri- Review 25 (10): 25–32. tage-value assessment study based on the findings of Wang, Y., K. Matsumoto, and M. Sawaki. 2019. “STUDY ON this study can be developed. CONVERSION STORE RENOVATION EXAMINATION AS WELL AS ITS EFFECTIVENESS AND ISSUE IN LANDSCAPE PRESERVATION OF HISTOR-ICAL DISTRICT—The Case OF Wudadao Historical District, Tianjin, China.” Journal of Disclosure statement Architecture and Planning 84 (766): 2617–2627. doi:10. No potential conflict of interest was reported by the 3130/aija.84.2617. author(s). Wang, H., X. Yuan, K. Wei, H. Chang, and X. Chen. 2017. “Historical Block Preservation and Renovation.” Planners 04: 143–147. Wu, Z., Y. Fang, and Z. Shi. 2019. “Research on Spatial Forms Funding of Historical and Cultural Blocks Based on Space Syntax: This research was funded by the Liaoning Provincial Social Taking the Changmen Historical and Cultural Block in Science Planning Fund Project; grant number - L22BGL019. Suzhou as an Example.” Architecture & Culture 12: 36–38. JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 15 Xia, Y. 2021. Research on the Renovation of Non Sector in Dijon.” Journal of the City Planning Institute of ProtectedTraditional Commercial Blocks in Old Cities– Japan 35: 709–714. A Case Study of Longfu Temple Area. Beijing, China: North Zeayter, H., and A. M. H. Mansour. 2018. “Heritage China University of Technology. Conservation Ideologies Analysis – Historic Urban Yang, C. 2022. “Cultural Landscape Space System: A Case Landscape Approach for a Mediterranean Historic City Study on the REGENERA-TION Planning of NON-HISTORIC Case Study.” HBRC Journal 14 (3): 345–356. doi:10.1016/j. and Cultural Old City of Tangyin.” CITY PLANNING REVIEW hbrcj.2017.06.001. 05: 81–92. Zhang, S. 2012. “On the Basic Characters and Challenge of Yukinobu, W. 2000. “Study on the Control of Storeboards in the Conservation Mechanism in Historic and Cultural a Historic Landscape in France Case Study in Safeguarded Cities.” Urban Development Studies 19 (9): 5–11.
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