Spatial Syntax Analysis of the Evolution of the Water System and Garden Distribution Relationship in Suzhou: 13th–20th Centuries

Abstract

In the present study, we used the axis model in the spatial syntax approach to analyze the evolution of the water system in Suzhou, China, from the 13th to the 20th centuries and its relationship with the distribution of gardens in the city. The distribution of the authoritative mainstream gardens appeared to be directly affected by the water system, and the gardens located in the areas with high water integration in each period were well preserved. From the 13th to the 17th centuries, gardens in areas with high water integration were all owned by the government and the class with social authority. This was consistent with the patterns for the hierarchical distribution of traditional urban space in China. However, in the 19th century, the gardens in areas with high water integration were owned by the class with social authority and the merchant class, reflecting characteristics different from the traditional pattern. The temple gardens in commercial areas with high water system integration were well preserved. Given the disruption of the surrounding water system, their original isolation from the water system was averted, turning them into public areas for social and public activities. In the 13th and 17th centuries, gardens located in areas with high and low water system integration took advantage of the surrounding water systems for landscaping, demonstrating the gardening principle according to local conditions. However, in the 19th and 20th centuries, the water system decreased sharply in many areas, and gardens built in areas with high water system integration were no longer thus situated. Traditional techniques for diverting water into gardens gradually disappeared. This study revealed that the preservation of gardens in Suzhou was largely due to the pattern of their distribution in the urban structure, and the gardens preserved to date have benefited from their location relative to the urban spatial structure of the 19th century. Private gardens, which embody the elegant taste of the literati, strongly resisted the aesthetic invasion from commercialization, however, and were also developed and preserved. Their social and spatial attributes were transformed by commercialization, presenting a contradictory yet complementary relationship between traditional garden culture and commercial development in Suzhou.

1. Introduction

In the 13th century, many large-scale and prosperous cities appeared in China [1], including Suzhou. Marco Polo described Suzhou at that time as “a huge and magnificent city…, the number of residents is astounding” [2,3], and he also hailed Suzhou as the “Oriental Venice” because of its dense water networks. Suzhou did not undergo significant changes from the 13th to the 20th century, and there remain similarities in the city’s physical form over time. According to Frederick Moto, its urban morphology had extraordinary stability, but although the city walls, moats, gates, and lanes have remained the same from the 13th to the 20th centuries [4], the water system, including the drainage and transportation of the entire city, has been constantly changing [5]. The water system in Suzhou was formed in the Song Dynasty, and a few tributaries were added by the Ming Dynasty [6]. In the Qing Dynasty, many water systems disappeared with the rapid increase of the urban population and the silting of waterways [7].

The construction of Suzhou Gardens was closely related to the distribution of the urban water system. According to Jiazan Wei, a historian of the Suzhou Gardens, Suzhou’s superior natural geographical environment has contributed to the development of its gardens [8]. Due to the abundance of groundwater, water can be accessed by digging just one meter below the ground when building a garden, and most gardens integrate the urban water system as part of their landscape design. Wang verified the practice of diverting water into the gardens in Suzhou by looking at the Couple’s Retreat Garden, the Master of the Nets Garden, and the Canglang Pavilion as examples [9]. Yun used the space syntax approach to analyze the water system in the 18th-century Map of Gusu City in the Qianlong Period of the Qing Dynasty and found that a large number of gardens were adjacent to canals with poor transportation function and low integration while also proving the efficacy of the space syntax approach to analyze rivers in Suzhou [10].

Most of the above studies focused mainly on the gardens and particularly the impact of the urban water system on garden construction. In this study, we analyzed the evolution of the water system morphology in the urban spatial structure and its relationship with the evolution of garden distribution. The space syntax approach was used, and the evolution of the water system of Suzhou from the 13th to the 20th century and its relationship with the distribution of gardens were studied based on the Map of Pingjiang in the Song Dynasty (1229), the Canal Map of Suzhou in the Ming Dynasty (1636), the Map of Gusu City in the Qing Dynasty (1872), and the Latest Suzhou Tourist Map (1943). Although the four maps were created in different historical periods, they are representative of the distribution of water systems in Suzhou during the Song, Ming, and Qing Dynasties, as well as the Republic of China [11]. The present study followed three steps. First, the four maps were redrawn based on GIS information, and the axis model in the space syntax approach was used to analyze the water systems of Suzhou in each period. Second, based on the results of the axis model and the location of gardens in each period, the relationship between the water system and the distribution of gardens was analyzed. Finally, the evolution of the relationship between the water system and the distribution of gardens in Suzhou was explored.

2. Materials and Methods

The space syntax approach for analyzing spatial structure was first proposed by Bill Hillier in 1974 [12,13], and it has been used to study modern city spaces [14]. Space syntax is a geometric representation of spatial elements based on the analysis of configurational relationships [15]. It can abstract the relationship between spaces into a connection diagram represented by an axis and then allow a topological analysis of the spatial integration, thus yielding the variables for space morphology analysis [16,17]. An axis represents the longest passable free line of sight in space, and the sum of all axes represents the topology of the urban space. In axis model analysis, each street is represented by an axis, broken when the direction of the irregular path changes [17,18,19,20]. Most current studies analyse urban space by generating street axis models and amplifying various behavior patterns [21,22,23]. Suzhou is different from most cities where streets run through the whole space: in Suzhou, the rivers function similarly to streets in other cities [16,24]. Generally, most ordinary houses face the street at the front door, and the river at the back door (Figure 1), and boats are a daily means of transportation [25], so most families diverted water to their gardens so they could dock their private boats [26]. We, therefore, used the axis model for spatial syntax to analyze the water system in Suzhou.

The earliest map of Suzhou, the Map of Pingjiang in the Song Dynasty, recorded six rivers running from north to south and 14 from east to west. The map had no scale bar and was marked with four azimuths (i.e., east, south, north, and west). According to modern measurement methods, these azimuths were inaccurate but off by 7°54′ to the south by east. In terms of scale, the north-south dimension of the city was 1:175, and the east-west dimension was 1:167, which was incorrect [27] (Figure 2). The Canal Map of Suzhou in the Ming Dynasty includes more than 100 canals. It also was not drawn to scale and only depicted the spatial distribution of the river channels. It also lacked a scale bar (Figure 3). Compared with the Map of Pingjiang, the water system in the map had increased, and these channels were mostly used for grain transport. Many gardens and the Suzhou Prefectural Schools diverted peripheral rivers to the garden or school. The river channels in this period were the greatest in the history of Suzhou [11]. The Map of Gusu City in the Qing Dynasty recorded the canals clearly, but again, the scale was not accurate [11] (Figure 4), and there was no scale bar. The Recent Suzhou Tourist Map from the Republic of China drew the rivers according to scientific proportions (Figure 5) and was labeled with a scale bar.

The four maps discussed above have high resolution, and the city outline, water systems, roads, gardens, and buildings are clear. Although some maps were not drawn to the correct scale, the important role of the water system in Suzhou’s urban structure was revealed effectively. Although these maps all showed the distribution of water systems and gardens in Suzhou, great differences in the scale and representation of the same river are apparent among different maps. The spatial syntax analysis based on only the axis of these maps results in discrete integration values between the same urban patterns. Therefore, this study was conducted using the scale of the Recent Suzhou Tourist Map as the reference according to the GIS method, the distribution of the city walls, rivers, and gardens in the four maps studied was sequentially extracted, and ArcGIS 10.2 software was used to map them onto the Suzhou Map with the correct scale, thus redrawing the maps of Suzhou from the 13th to the 20th century [28,29] (Figure 6).

According to Figure 6, the water systems in Suzhou in the 13th century were almost parallel to and closely connected with the roads. Almost all roads were built along the rivers, and there were more rivers than roads. In the 17th century (Figure 6), the distribution of rivers was similar to that in the 13th century, but many small tributaries were added. The map did not include any information about roads; however, as seen in Figure 3, bridges over the rivers indicated that the rivers were still closely connected and parallel to the roads. In the 19th century, the water system in Suzhou decreased sharply, but there were many more roads than in the 13th century (Figure 6). The main rivers were still closely connected with the main roads. In the 20th century, the water system within the city decreased further, while the water system outside the city increased. The rivers parallel to the main roads remained unchanged, and many small tributaries disappeared.

In summary, the distribution of rivers and roads in Suzhou was very similar from the 13th to the 17th century, and from the 19th to 20th century, only the main rivers were closely related to the main roads. The degree of integration of the rivers from the 13th to the 17th century, thus, represents the degree of integration of road networks in the same period, while the degree of integration of the rivers from the 19th to the 20th century differs from that of the roads. Therefore, when analyzing how integrated rivers were in this period, the road situation was supplemented for additional description.

After obtaining the standardized map, as shown in Figure 7, the standardized axial maps of Suzhou in each period were made. The city walls in the four maps were set as the boundaries, and the axis of the water system was manually drawn in AutoCAD and then imported into DepthMap for calculation. After the calculation, the node count value was checked to verify the accuracy of the axis model. After confirming that all axes were correct, the integration (a predictive index of the density of pedestrian access) of the water system axis model was calculated [16]. The colors from red to blue indicate the level of integration from high to low. Generally, the higher the integration, the more cultural, economic, and political functions the area has [18]. Based on this principle of analysis, the axis model and integration analysis results in each period were compared with the distribution pattern of gardens, enabling assessment of the relationship between the integration of rivers in different periods and the distribution of gardens and their evolution.

3. Results

3.1. Axis Model Analysis of the Water System in the 13th Century

In the Song Dynasty, highly integrated water systems appeared primarily in the city’s central area, and water systems near the north and south ends of the city had the lowest levels of integration (Figure 7). Most temple gardens were distributed in areas where the water systems were highly integrated, and private gardens were generally in poorly integrated areas. Temple gardens in the Song Dynasty were highly accessible and mostly located in the city’s core areas. In contrast, private gardens were less accessible and tended to be located in the city’s fringe areas. This reflects the mainstream characteristics of temple gardens in the Song Dynasty; many well-known temples, such as Baoen Temple, Longren Temple, Xuanmiao Temple, Kaiyuan Temple, Dinghui Temple, and Beichan Temple, were located in areas with a high level of water integration or the middle of the water system. There were some temples in the less well-integrated area, but these were only referred to as an unnamed “temple” in the Map of Pingjiang in the Song Dynasty (Figure 2)—that is, these temples were not very famous. The private gardens mentioned in historical materials, such as the Canglang Pavilion, Lepu Garden, and Nanyuan Garden [8], were generally located in areas with low water system integration (Figure 7).

Regardless of the degree of integration, all temple gardens were surrounded by water systems (Figure 7) and showed the same construction characteristics. Water is a symbol of pure land in Buddhism. Surrounding temples with water and entering temples through bridges was a typical feature of Buddhist temples in the Southern and Northern Dynasties (420–589) and even the Song Dynasty [30] when temple structure was influenced by this belief in pure land. The distribution of water systems in Suzhou provided the temples with the convenience of creating an environment that embodies the idea of pure land, and the characteristics of temple gardens highlighting Buddhist connotations are closely tied to the city’s water system. Meanwhile, there were only a few water systems around most private gardens, and some even had no apparent access to water. This indicates that the construction of private gardens in the Song Dynasty was not closely tied to the urban water system (Figure 7).

3.2. Axis Model Analysis of the Water System in the 17th Century

The distribution of highly integrated water systems in the Ming Dynasty was similar to that in the Song Dynasty, as they were generally located in the central area of the city (Figure 8). The water systems at the north and south ends of the city were more highly integrated in the Ming Dynasty than in the Song Dynasty, and a large number of private gardens were densely concentrated in areas with a high level of water system integration, while only a few private gardens were in areas with moderate or low integration. This confirms the suggestion that the Ming Dynasty was the heyday of private gardens in Suzhou [8]. The temple gardens in areas with low water system integration from the Song Dynasty had completely disappeared by the Ming Dynasty, while the temple gardens in areas with moderate or high integration in the Song Dynasty were preserved. Overall, the number of temple gardens decreased significantly in the Ming Dynasty compared to the Song Dynasty, and they tended to be replaced by private gardens.

The family gardens of the Wen family—who were well-known in garden design, culture, and art—were mostly located near highly integrated water systems; these included the famous Tingyun Pavilion built by Zhengming Wen; the Yaopu Garden, the most prosperous medicine garden in the west of the city built by Zhenmeng Wen; and the Xiangcaocha Garden, built by Zhenheng Wen [31] (Figure 8). The Wen Gardens were widely admired in the Ming Dynasty, and the family’s gardening style influenced the development of the gardens of literati to the south of the Yangtze River [32]. Ao Wang’s Yilaoyuan Garden [33], which was highly respected by the Wen family, was also located in an area highly integrated into the water system (Figure 8). Although the gardens located in areas with low integration were labelled with names, the garden owners’ prestige in Suzhou areas was not as high as that of the Wen family, and relevant historical records are scarce [8]. In summary, during the heyday of the Ming Dynasty, private gardens located in highly integrated areas were highly influential, while those in areas with low water system integration were generally ordinary private gardens.

3.3. Axis Model Analysis of the Water System in the 19th Century

The number of water systems in the Qing Dynasty greatly declined, but the distribution of water system integration was similar to that in the Ming Dynasty (Figure 9). Although many tributaries disappeared, and only the main water system remained, the highly integrated water systems were still located in the city’s central area. The water system near the south city wall was less well integrated in the Qing Dynasty than in the Ming Dynasty, but the water system near the north city wall was more highly integrated. This indicates that the multicultural and commercial functions of the water system in the city’s central area continued from the Song to the Qing Dynasty, while the water system in the south city wall area declined and that in the north city wall area increased. In the Qing Dynasty, most gardens were private and scattered in areas with different levels of water system integration. Temple gardens at this time were rare and mostly relics from previous dynasties, located in areas with relatively high-water system integration even in the 19th century (Figure 9).

Most of the gardens remaining in the Qing Dynasty were survivors from the Ming Dynasty, and most were built near water. Many gardens from the Ming Dynasty disappeared as the water systems disappeared in the Qing Dynasty. The water system in the area of the Wen family’s gardens in the Ming Dynasty disappeared (Figure 9), which accelerated the gardens’ demise. There was almost no mention of the Wen Gardens in the historical materials from the Qing Dynasty [31]. According to the Map of Gusu City in the Qing Dynasty (Figure 4), private gardens included the Humble Administrator’s Garden, the Yiyuan Garden, the Huanxiu Villa, and the Canglang Pavilion, which were located both in areas with high-water system integration (e.g., the Humble Administrator’s Garden and the Yiyuan Garden) and areas with low integration (e.g., the Canglang Pavilion and the Qu Garden). The distribution of temple gardens, such as those of the Shilin and Baoen Temples, was similar to that of private gardens.

Numerous shops and stores were concentrated around highly integrated water systems [34], which is very consistent with the description that the city “is no longer famous for its gardens, but for its shops and market” [35] (Figure 10). This finding is also consistent with previous studies showing that the Suzhou Gardens in the 18th century were built near rivers with low levels of integration [10]. The results of the axis model of the water systems in the 19th century thus also reflect the characteristics of the distribution of water systems and gardens in the city in the 18th century—that is, there were a large number of business districts in areas with high accessibility and multiple functions, while the gardens retreated to the sub-core or fringe areas of the city.

3.4. Axis Model Analysis of the Water System in the 20th Century

Compared to the Qing Dynasty, many tributaries disappeared in the 20th century, but the main water systems in the city were preserved. A key difference was that many tributaries were derived from the city’s northwest corner and connected to the inner-city water system during this period (Figure 11). The highly integrated water systems were distributed in the central area and near the north city wall, while the water systems along the east and south city walls had low levels of integration. Compared to the Qing Dynasty, the integration of the water system in the area near the eastern city walls declined, whereas the systems near the north city walls were more integrated. Parks appeared for the first time, in addition to temples and private gardens (Figure 12). Most of the private gardens were from the Qing Dynasty and converted to public tourist sites, and they remained generally distributed in water system areas with high integration. Only the Liuyuan Garden, the Xiyuan Garden, the Jingyuan Garden, the Canglang Pavilion, and the Keyuan Garden were located in areas with low integration. Only a few temple gardens remained, most located in areas with a high integration in the 20th century. As an emerging form of public space, parks were also located in areas with high water system integration.

4. Discussion

4.1. Water System Changes Affect the Distribution of Mainstream Authoritative Gardens

The main garden types were generally distributed near highly integrated water systems throughout the study period from the 13th to the 20th centuries. For example, temple gardens in the 13th century, private gardens in the 17th century, and parks in the 20th century were all situated in the city’s central area. Most of the influential gardens were also located in areas with highly integrated water systems, and they constantly migrated due to changes in the areas where water systems were integrated. For instance, the temple gardens in the Song Dynasty were preserved in the Ming Dynasty due to their location in the high-integration area of the city. In contrast, the famous gardens of the Wen family in the Ming Dynasty, which were located in high-integration areas, disappeared due to the decline in the surrounding water system in the Qing Dynasty. The newly built parks in the 20th century, the latest form of public green spaces in modern China, are highly influential and reflect the thoughts and trends of the times. The water system integration of an area thus tends to indicate the mainstream and regional influence of the gardens in the area—that is, the higher the accessibility, the more mainstream and authoritative the gardens located in the urban core area.

The results suggest that the key authoritative gardens tend to concentrate in the central area of an urban spatial structure. Take the Baoen Temple as an example: it has been preserved since the Song Dynasty and is now a landmark of Suzhou. In the Song Dynasty, it was located in an area with only moderate water system integration. In the Ming Dynasty, the integration of the surrounding water systems became higher, while in the Qing Dynasty, although the surrounding water systems declined, the overall integration of the water systems continued to increase until the period of the Republic of China, when the integration reached the highest level in the city. Thus, It has retained its status as a landmark and well-known Buddhist temple garden.

Take the Humble Administrator’s Garden as another example: it was built in the Ming Dynasty and has been preserved as a world cultural heritage site. It was located in an area with only moderate water system integration in the Ming Dynasty; at the time, it was less famous than the Gardens Wen family, and it switched ownership from Wang Xianchen to the Xu family due to a bet [8]. In the Qing Dynasty, the integration of the surrounding water systems increased and reached the highest level in the city during the period of the Republic of China. The status of the Humble Administrator’s Garden was thus established among Suzhou gardens. These two examples illustrate how changes in the structure of the urban water system have a subtle influence on the preservation of urban gardens and the promotion and continuation of their popularity.

It is worth noting that the temple gardens located in areas with high water system integration in the 13th century, such as Longren Temple (Figure 7), were locally important temples in Suzhou. In the 17th century, however, private gardens located in areas with high water integration were owned mainly by the Wen family, typical members of the class of social authority in the city (Figure 8), and the gardens in non-essential areas were mostly civilian. These distribution characteristics are consistent with the traditional Chinese urban structure, in which the government or groups of high social class are located in the city’s core area. This pattern changed in the 19th century. Looking at the distribution of gardens in areas with high water system integration in the 19th century, it can be found that there are not only gardens owned by members of the class with social authority, such as the Humble Administrator’s Garden owned by Zhiwan Zhang but also some emerging commercial gardens. Some of these existed in the 17th century, such as the Jiangxi Huiguan Garden, which was a commercial garden rebuilt based on the original garden in the 17th century, when it was not located in an area with high water system integration (Figure 8); in the 19th century, however, the garden was located in an area with high water system integration (Figure 9). In addition, some newly built commercial gardens in the 19th century, such as the Liangguang Huiguan Garden, were located in areas with high water system integration. The change in distribution pattern indicates that the gardens in the core area of Suzhou City in the 19th century were no longer entirely owned by those of high social class, such as scholar-officials. This is closely related to the development of the commodity economy in Suzhou in the 19th century. It also implies that the pattern of urban class distribution in Suzhou at that time broke up the class stratification in traditional Chinese society. The mainstream authoritative gardens of Suzhou were owned by both scholar-officials and merchants in the 19th century. In the 20th century, all gardens were developed for public service purposes, and their social class attributes disappeared. Most of the preserved gardens were located in the core area, indicating that making urban space public had become a development goal of Suzhou City.

4.2. Water System Decline Turned the Formerly Isolated Temple Gardens into a Center of Diverse Social Activities

Changes in the water system in Suzhou have weakened the Buddhist implications of the external environment of the temple gardens. The temple gardens in the 13th century were surrounded by water systems, symbolizing the Buddhist belief in pure land. In the 17th century, most of the water system remained intact, which did not affect the temple gardens, but in the 19th and 20th centuries, many of these water systems disappeared. For example, the Baoen Temple was surrounded by water from the 13th to the 17th centuries, but the water system gradually broke down in the 19th century: only the river channel in front of the temple remained in the 20th century (Figure 13). This is true of most of the preserved temple gardens. Ironically, some temple gardens were preserved due to the gradual development of the surrounding areas. For example, the road in front of the Baoen Temple became a well-known commercial district in the 19th century, and many shops emerged on both sides of the street in front of the Xuanmiao Temple (Figure 10). The development of the area contributed to the preservation of the temple gardens, but due to the increasing land use, the spaces belonging to the temples have been continuously divided, and the Buddhist implications heightened by the water system have also disappeared. Although the prosperity of areas with high water system integration is conducive to preserving temple gardens, the overwhelming trend of economic development has also changed the cultural connotations of the temple gardens’ external environment.

This influence changed the temple gardens from isolation and detachment from the mundane (due to the water system division) into a place that accepted the mundane. These temples, such as the Xuanmiao Temple, have gradually evolved into urban public spaces where citizens gather due to their proximity to commercial streets (Figure 10). The courtyards of the temples are often gathering places for different types of social activities, strengthening the social and political relations between urban and rural areas [36]. It can, thus, be concluded that the change in the urban water systems led to changes in the urban structure, and the original connotations and single functions of the temple gardens located in the core area of the urban structure disappeared. The social functions and cultural implications of temple gardens underwent a complete reversal solely due to the disappearance of a small water system.

4.3. Weakening Relationship between Water System Accessibility and Gardening Techniques

In the 13th century, the water system separated gardens from the urban landscape. For instance, the Canglang Pavilion was built near water, and the surrounding water system naturally became a barrier between the pavilion and the outside city [37,38], while the Lepu Garden adopted the strategy of diverting water into the garden to build a pond [39]. In addition, the Baihuazhou Courtyard diverted outside water into the garden. In the 13th-century Map of Pingjiang, it can be seen that water passes under the garden wall and is introduced into the garden to form a pond (Figure 14). In the 17th century, the number of tributaries in the water system increased, and most houses were equipped with water walls or river ports, or water was diverted into courtyards to park boats [26]. As shown in the Canal Map of Suzhou in the Ming Dynasty, the Suzhou Prefectural School introduced water into the campus to form a waterscape (Figure 14). There was a boom in garden construction [40], and water was often diverted to build ponds and canals in private gardens [9], such as the Master of the Nets Garden, the Sheyuan Garden [10], and the Xiangcaocha Garden [41]. The distribution of gardens built in the 13th and 17th centuries has no apparent relationship with integrating the surrounding water system. Regardless of whether the gardens were located in areas with high or low integration, because of the rich water systems around them, their distribution was not directly related to the city’s core area.

By the 19th century, however, the construction of new gardens gradually stopped. Most of the gardens in the city were from previous dynasties. Some private gardens still have external water systems, showing evidence of water diversion into the gardens [10]. For example, the She Garden, renamed the Couple’s Retreat Garden in the Qing Dynasty, is adjacent to the moat east of the city, an area with very low integration. Meanwhile, the Canglang Pavilion (Figure 14) faces a water system with a low integration, which not only serves as the boundary of the garden but also provides a scenic view of the garden. The Huanxiu Villa and Yiyuan Garden (Figure 14), built in the Qing Dynasty, are both located in an area with high water system integration: the water system is located in the center of the gardens, and there are no water inlets found around the garden wall [37]. The tall garden wall is intended to block the scenery outside the garden, many water systems outside the garden have broken up or disappeared, and there is no longer any water to divert. The water system outside the garden is no longer used to form a scenic view of the garden. Parks appeared in the 20th century, and although there are water systems around them, these features are typically far away. The construction of parks has tended to reflect the functionality emphasized by Western gardening. Traditional Chinese garden construction techniques—that is, diverting water into the garden for landscaping or borrowing the water system outside the garden to form landscaping—have gradually faded out of park design [42].

5. Conclusions

The city of Suzhou is a special case that supports applying the space syntax approach in the analysis of river integration. It provides a new perspective for evaluating the research of street integration and expands the scope of the space syntax approach. The changes in the spatial distribution of water systems in Suzhou are like an invisible hand which has subtly affected the distribution and preservation of Suzhou gardens. The preservation of Suzhou gardens has largely been due to the pattern of their distribution in the urban structure. Well-known gardens such as the Humble Administrator’s Garden and the Lion Grove Garden have been preserved not only because of their fascinating beauty but also because they have been located in the city’s core area in various periods. The preservation and continuation of Suzhou Gardens are, thus, somewhat coincidental. In continuous changes in the urban structure and the continuous migration of the core area, one garden with a beautiful scenic view gradually becomes popular, while another similar garden in a non-core area faded out of people’s sight because of its location. This result highlights an essential point in the research of Suzhou gardens—that is, a garden’s recognition is not entirely due to its superb design but partly due to its location within the city, which brought it into the spotlight. For many gardens that have been lost, it may not have been because of their poor design but rather due to changes in the urban spatial structure that caused the areas surrounding these gardens to lose their vitality, thus leading to their eventual disappearance.

According to the results of this study, the preserved Suzhou gardens benefited from their location in the urban spatial structure of Suzhou in the 19th century, and this distribution pattern remained until the 20th century. The temple gardens from the 11th century and private gardens from the 17th century have quietly disappeared in the ever-evolving urban space. By analyzing the maps of Suzhou in various periods, Mote and Xu found that the urban structure of Suzhou has shown relatively greater stability since the 13th century: the outline and main roads have not changed much [4,36]. In fact, through the spatial syntax analysis of the rivers that changed slightly and were consistent with the function of roads, it was found that minor changes in the water system in each period have changed the core area of Suzhou city many times from the 13th to the 20th century. The continuous migration and development of the core area resulted in the preservation and continuation of the gardens currently present in Suzhou.

In this study, we revealed the evolution characteristics of the relationship between the water system and the distribution of gardens in Suzhou and revealed an interesting phenomenon: generally, Suzhou gardens are considered carriers of the elegant aesthetic concepts of the literati rather than carriers of commercialization. Ironically, the gardens that embody the elegant taste of the literati are preserved mostly due to the commercial development in the surrounding area. While resisting the aesthetic invasion of commercialization, Suzhou gardens have benefited from it and are still preserved. Thus, a contradictory and complementary relationship exists between Suzhou’s traditional garden culture and the emerging commercial culture, guided by the invisible hand of the city’s water systems. Furthermore, unlike the distribution of gardens in the 13th and 17th centuries, when the gardens in the core area were owned by members of the class with social authority, the gardens in the 19th century were owned by members of the class with social authority and the merchant class. The facts revealed that the mode of Suzhou’s urban operation and the land use attributes of various classes were different from those traditional in Chinese society at that time, which provides clues for the study of the emergence of modern Chinese society from the traditional class model.