无人机倾斜摄影技术支持的古驿站城镇形态特征研究

Study on Urban Form Characteristics of Ancient Transportation Fortress Based on Drone Tilt Photography Technology

城镇形态是解读古代交通走廊沿线小城镇空间特征和历史演化趋势的一把钥匙。古驿站作为一种特殊的交通型古镇,对于丰富对交通走廊沿线古代城镇的全景式认知起到重要作用。本文以张库大道沿线的鸡鸣驿为例,通过无人机和倾斜摄影技术,进行城镇形态中的空间、功能和细部院落等要素的城镇形态特征分析和解读。首先,通过城镇数字化建模显示古今以来城镇物质空间形态基本保持不变。其次,基于机器学习方法进行功能识别,发现随着清末张库大道由兴至衰,城镇功能转向为以居住为主,邮驿功能逐步退却。再次,在院落细部形态上,基于三维模型微观分析,发现很多院落内部的建筑存在废弃和空置。最后,通过无人机倾斜摄影和三维建模,提供了大批量、低成本的高效获取城镇空间要素的途径,为城镇形态分析提供技术支持,为增进交通走廊沿线小城镇的系统性认知提供借鉴。

Urban form is a key to understanding the spatial characteristics and historical evolution of old towns along regional transportation corridors. The ancient transportation fortress, as special type of small town, and a node and hub with multiple function was used to play an important role in enriching the understanding towards the ancient Silk Road and contemporary ’Belt and Road’. This paper selects the Jimingyi in Zhangjiakou City along the ’Northern Grassland Silk Road’ as case study, constructs a 3D model through drones and tilt photography technology.It identifies the spatial elements such as town spatial layout, town function, and street and courtyards form. First,based on the 3D digital spatial model, it finds that the urban spatial pattern is almost keep still and do not change much. Second, by method of machine learning, it finds that the functions of zones within city are dramatically to residential use. It reflects the decay of transportation function with the decline of the routes of trading corridor in late Qing Dynasty. Third, in aspect of streets and lanes within town, more details in the model show that the buildings inside some courtyards are abandoned and walls are collapsed. This paper provides a low-cost, quick and efficient way to obtain urban form elements through drone and 3D modeling technology. It plays a direct role in presenting the urban form analysis to small towns. The application of this paper is to other similar small cities and towns along transportation corridor lies in that it will provide policy implications for improving the new technology supported urban planning and design along transportation corridor.