Evolution of Slender West Lake as a cultural landscape
The Slender West Lake scenic area is located northwest of Yangzhou City, Jiangsu Province, China. The area covers 12.23 km2 and was included on the World Heritage List in 2014 as a world heritage site for the Grand Canal. Slender West Lake was a garden landscape that was transformed from the military landscape formed by city moats and canals that was developed over 2500 years. In the mid-18th century, a large number of suburban villas and gardens built by salt merchants in different locations along the moats were connected and organised to welcome a southern inspection by Qianlong Emperor. This area became a beautified landscape belt alongside the lake with its garden scenery uniting the natural and human landscapes (UNESCO 2008). Slender West Lake is a typical demonstration of traditional public tourism destinations that represents the tastes and lifestyles of traditional Chinese society (Fig. 2).
The history of the Slender West Lake cultural landscape can be traced 2500 years back to the establishment of the earliest city in Yangzhou. The first city of Yangzhou, named Hancheng, was built in 486 BCE on the northern bank of the Yangtze River, which was a strategically important region between northern and southern China. A water network was then developed during the evolution of Yangzhou City because nearly every dynasty had redevelopment of the city and extended the moat system around the city (Yang et al. 2016). While these cities were built and demolished throughout the history of the area, all the moats were retained to form a military water network in northwest Yangzhou. During the Qing Dynasty (16445–1912), Yangzhou was one of the most prosperous cities in the Qing empire (Finnane 2004) and Slender West Lake was transformed from a military moat system into a recreational landscape. The local officials and salt merchants built many gardens and villas on the lakeside to please the Emperor and cater for their socio-cultural practices. Eventually, there were more than 100 gardens and public buildings built along the 3-km watercourse of Slender West Lake (Fig. 3).
The Slender West Lake scenic area is a typical Chinese cultural landscape with distinctive characteristics. As a designed landscape, Slender West Lake was the last and the largest construction of traditional Chinese gardens south of the Yangtze River during the last imperial dynasty (Han et al. 2011). As an organically evolved cultural landscape, Slender West Lake was continually developed from a military landscape into a recreational landscape over 2500 years. As an associative cultural landscape, Slender West Lake includes highly symbolic and metaphorical meanings and a rich, humanistic attachment to natural features. Therefore, Slender West Lake has the features of the three cultural landscape categories, which provide an important example for this study on digital heritage documentation.
Challenges in the conservation and management of Slender West Lake scenic area
The fragmentation of heritage information is a major obstacle in the efficient conservation of Slender West Lake scenic area. As a cultural landscape heritage, the daily management of Slender West Lake requires a high degree of integration of multi-disciplinary, multi-period, and multi-sectoral information. However, the current heritage information is distributed among different institutions and in different forms and formats. Management departments, museums, libraries, archives and planning bureaus hold different sets of information about the historical and current status of Slender West Lake. However, this information lacks an integrated platform, which leads to the inability to fully consider the multi-level value of cultural heritage in making management decisions. For example, in the contemporary adaptive use and restoration of some sites in Slender West Lake, their ecological and social values may be emphasised, but its cultural and historical values may not be fully considered because of the lack of supporting information. Therefore, the establishment of an integrated digital information platform for cultural landscapes is urgently important.
There are technical challenges in incorporating the intangible cultural heritage information during the process of conservation in the Slender West Lake scenic area. The landscape itself has not only accumulated a large amount of tangible cultural relics, but also a large amount of intangible cultural heritage information during its 2500 years of evolution. Most of this information is detached from physical landscape conservation and used for heritage research as background information. Owing to the lack of an effective platform for data dissemination, the intangible cultural heritage information has not been fully incorporated into daily management. Therefore, it is difficult to understand the value of heritage and protect its integrity. Many culturally rich places have not been properly protected and interpreted; thus, the focus of this research is to explore how to systematically organise the information about the intangible heritage elements, integrate them into the heritage information management platform and support the conservators’ related decisions.
The daily maintenance and restoration of the Slender West Lake scenic area lack a systematic digital recording system. In its evolving landscape heritage, the continuous maintenance, renewal, restoration and monitoring of Slender West Lake forms a management system with local characteristics. The records of site changes and interventions are important information for assessing the authenticity of landscape properties. However, there is currently no systematic registration platform and the user experience information of heritage management lacks effective transmission. Management activities mainly rely on field experience or paper materials; therefore, using a digital information system to record and monitor daily management work is of great significance in the sustainable development of Slender West Lake.
Like many other cultural heritage administrations, the local management team of Slender West Lake need more heritage data, technical capabilities and related technical resources. The existing national and regional heritage databases are relatively broad in scale and cannot be used for the daily management of the Slender West Lake scenic area. As a direct tool for the conservation and management of cultural landscape heritage, the data structure and functional settings of the designed digital information system should reflect the characteristics of the heritage itself and the preferences of local management teams. Therefore, it is necessary to explore a contextualised heritage information system for Slender West Lake.
Data collection and analysis
The first step was to investigate the history, fabric, use and association of the landscape with the aim to define its cultural significance and related features. Existing conservation documents, including local chronicles, historical materials, conservation plans and professional reports, were collected from local management authorities. These documents were then analysed using a content analysis method, which provided a comprehensive understanding of the evolution of the Slender West Lake scenic area. Maps were derived from the documentary evidence as a special dataset because they are direct representations of the landscape that provide significant material for digital representation. An archaeological survey map created in 1979 and a topographic map from 2005 were combined and mainly used as a spatial reference for the following investigation and geo-database design.
Site observations were simultaneously conducted to explore Slender West Lake’s physical aspects. The condition of the physical environment was recorded through sketches, notes and photographs. The connections between the tangible and intangible aspects of Slender West Lake were identified. A landscape character assessment process identified 25 landscape compartments in Slender West Lake, with distinctive landscape characteristics and certain cultural landscape values. Six types of landscape character-defining components were identified, including topography, man-made water, transportation, building, rockery and vegetation.
Based on the understanding of both the history and current condition of the landscape, semi-structured interviews were conducted with the landscape stakeholders to explore their information requirements for landscape conservation and management. Five different types of stakeholders were interviewed: a heritage conservation planner, a park manager, a local historian, an on-site tour guide and a tourism developer. Each stakeholder was asked to answer an open question: ‘In your view, what information should we be collecting and using to guide the conservation and management of Slender West Lake?’ The interview transcriptions were imported into NVivo 12.1 software (QSR International, Melbourne, VIC, Australia) for content analysis.
Three requirements of a digital information system for cultural landscapes were identified from the interview data. First, an inventory of tangible and intangible heritage components is required because it is an important reference for conservation and management. Information about these components must reflect their history, conservation significance, conservation guidelines and the current condition. This digital inventory must be systematically designed so that conservators find it easy to use, share and edit cultural heritage information. Second, Slender West Lake needs an integrated geo-database that can be used for on-site conservation practices. Conservation and management processes are undertaken in limited time and with limited resources. Thus, conservation managers require synthesised information to assist in their efficient decision-making. For example, the restoration work must be informed by reliable references to determine what sites and which parts of these sites can be restored. Third, tourism development was an important topic in the interviews. Both conservation managers and tourism developers wish to improve the quality of tourism in the Slender West Lake scenic area. The stakeholders described the many intangible aspects of Slender West Lake as important resources for heritage interpretation and enhancing tourists’ experiences.
Design of a cultural landscape geo-database for Slender West Lake
Three aspects of the cultural landscape of Slender West Lake were analysed: physical environment, landscape activity and landscape meanings. The historical evolution of each aspect was further examined separately to thus form a four-dimensional model of the cultural landscape evolution of Slender West Lake (Fig. 4). The physical and non-physical components were categorised into individual features so that their characteristics could be identified. The history of Slender West Lake was divided into 10 periods and the development of the landscape and each component were identified and visualised in the model, which provided the original structure for the digital geo-database design (Fig. 4).
Accordingly, five groups of feature datasets, including 18 major feature classes, were integrated into the digital information system for cultural landscapes (Table 1). The data about the historical condition and changes for each component were attached to the landscape sites or individual features as attributes. The intangible heritage of Slender West Lake was integrated into this database through the design of a framework for feature attributes (Table 2). The digital information system was then constructed using an ESRI ArcGIS 10.1 software (Environmental System Research Institute, Redlands, CA, USA). The base map was derived from the digital survey map in DWG format provided by Yangzhou City’s Planning Bureau. Most landscape components, such as buildings, water and plants, were all accurately illustrated on the map.
Table 1 The data structure of Slender West Lake geo-database Table 2 Feature Attribute in Slender West Lake geo-database: Intangible cultural heritage