基于数字测绘的西湖行宫园林遗址空间特征探析

Analysis on Spatial Characteristics of the Site of West Lake Temporary Imperial Palace Garden Based on Digital Surveying and Mapping

【目的】利用数字测绘技术获取西湖行宫园林遗址的三维空间信息,探析行宫园林的空间特征。【方法】以历史格局保存较完好的杭州西湖行宫园林为例,在文献查阅的基础上,以三维激光扫描为主要方式获取原始点云数据,经SCENE 2019.0软件处理,构建西湖行宫园林现状的三维点云模型,并增补缺失的历史建筑模型。从整体格局、空间感受和竖向视线关系3个方面进行量化分析,总结园林空间特征。【结果】西湖行宫园林依照地形山势规划出4层台地,台地内部再分隔出不同院落,满足戏剧观演、观景游览等活动需求;受地形所限,院落以横向并列排布的组织形式来增加空间层次;山脊线处以线性排布景点的方式形成带状空间,强化视觉引导。游览时的空间感受主要经历了4次由收至放的变化,且程度逐渐加深,至山脊线处给人极度开阔的感受。台层间的高差变化和路径多处转折,使登临时俯仰之间皆可互相眺望,形成竖向上的对景;山脊线处以借景手法收纳外部西湖风光,扩大园林感知空间。【结论】从还原历史空间感受的角度,对园林修复提出建议,并总结使用数字测绘方式进行传统园林空间分析的技术要点和优势,以期为同类传统园林的研究和保护提供参考。

[Objective]The West Lake Temporary Imperial Palace holds a position of great significance as a representative historical site encompassed within the UNESCO-designated cultural heritage complex referred to as the“West Lake Cultural Landscape”.Located at the southern foot of Gushan Mountain,the palace lies at the top of Gushan Mountain to the north and beyond the West Lake to the south.By merging the distinctive features of the royal palace gardens in Qing Dynasty and the Jiangnan mountain gardens,the West Lake Temporary Imperial Palace Garden exhibits a unique garden style and holds significant artistic and research values.Notwithstanding that the West Lake Temporary Imperial Palace has drawn increasing attention from scholars in recent years,relevant researches primarily focus on the analysis of garden space and the evolution of overall pattern,while the spatial characteristics thereof are mostly described by traditional methods that lack accuracy and quantitative conclusions.With the advent of digital measurement technology,it is now possible to achieve high-precision,non-contact and digital collection of spatial information,thereby effectively enhancing the accuracy of surveying and mapping.Furthermore,the aforesaid technology can also enable more quantitative research and analysis of the garden,and provide new ideas and methods for the research of traditional gardens.[Method]This research,by virtue of digital surveying and mapping,analyzes the spatial characteristics of the West Lake Temporary Imperial Palace Garden,which boasts a well-preserved historical layout.In addition,the research conducts a field research in conjunction with a literature review to obtain the original point cloud data about the site of the West Lake Temporary Imperial Palace Garden,with 3D laser scanning being adopted as the primary measurement method.The original point cloud data obtained is processed using SCENE 2019.0 software,based on which a 3D point cloud model is built for the garden to supplement missing historical building models.[Results]The spatial characteristics of the West Lake Temporary Imperial Palace Garden are summarized through quantitative analysis of the overall pattern,spatial perception,and line of sight thereof.1)The planning of the West Lake Temporary Imperial Palace Garden involves opening up a four-layer terrace in alignment with the mountainous terrain.Limited by the terrain,the four layers are mostly narrow and elongated spaces extending in an east-west direction.Courtyards are arranged separated from each other with courtyard walls,forming a unique layout of scenery.To increase the depth of courtyard,the Zhuyue Spring,Jiuxiang Pavilion,and Yulan Hall courtyards are arranged in a horizontal parallel form.The width of courtyard is larger than the depth due to terrain limitations,with a width-to-depth ratio of 3∶5.Courtyard spaces serve different functions,such as drama viewing and sightseeing activities.In contrast to the courtyard layouts on the mountainside and at the foothills,the scenic spots located at the ridge are arranged linearly within a distance range of 23-35 m.Horizontal strip spaces serve as a visual guide for visitors.2)The spatial experience of touring the West Lake Temporary Imperial Palace Garden is characterized by four changes from a closed to an open environment,with the degree of change deepening over time.Specifically,when touring the West Lake Temporary Imperial Palace Garden,you may experience a continuous jump between open and closed spaces,which creates a sense of psychological anticipation,enhances associations,and culminates in an extremely open and bright space at the ridge line.The multiple turns of touring paths and the variations in elevation differences between terrace layers provide various scenic spots with overlapping views,forming a rich set of views.Notably,the courtyard area of Zhuyue Spring features a clear line of sight relationship between the Guangbi Pavilion on the first layer and the Kanbi Pavilion on the second layer.Through the use of borrowing scenery,the ridge line showcases the external scenery of West Lake,expanding the perception space of the West Lake Temporary Imperial Palace Garden.[Conclusion]This research puts forward recommendations for the current garden restoration through the lens of restoring the historical spatial ambiance.1)It is suggested that the existing plants on the third and fourth floor should be properly pruned,removed or replaced;2)it is recommended to set up identification of historical architecture not yet been excavated or transformed,and set up relevant interpretation facilities.The research further summarizes the technical aspects and benefits of analyzing traditional garden spaces by digital surveying and mapping technologies,with a view to offering valuable insights into the research and preservation of comparable traditional gardens.