Analysis Method Of Urban Long-term Development Characteristics Based On Spatio-temporal-semantic Information Of Street Names

During the stage of rapid global urbanization,sustainable development has become one of the most important topics in the current urban construction process.It is very important for urban planning to fully understand the long-term evolution and development laws of cities in a scientific way,deeply comprehend the context of urban development,and grasp the characteristics of urban culture.It also can help to form the unique feature of urban culture and promote sustainable urban development.Urban development is not only reflected in the changes in the material forms,but also the evolution of the spiritual forms such as social life and urban culture.The exploration from a single spatial perspective about urban development can no longer meet the needs to fully understand the city.It is more helpful to grasp the overall urban development characteristics in combination with the soft environment such as history and culture of the city.Based on an innovative data perspective,the research used local chronicles as the main data source to construct a standard data set of urban street names that integrates three-dimensional information of time,space and semantics.The framework for exploring the long-term dynamic urban development characteristics was designed which is from a three-dimensional perspective of spatio-temporal-semantic and integrates technical methods such as text mining,spatial analysis and time series analysis.The framework is consisted of three aspects:mining the semantic information of place names,analyzing the evolution characteristics of urban spatial form and environmental semantics over hundreds of years,and analyzing the similarity of development characteristic between cities.The exploration realizes the rise from the shallow cognition of local chronicles to deep understanding of the laws of urban development and distinctive images.It aims to provide some valuable and useful theoretical basis and references for urban planning under the background of new-type urbanization.The main research work and conclusions are summarized as follows.（1）This paper proposed a semantic feature mining model of place names that integrates local chronicle knowledge.The implicit knowledge was extracted from complex and abstract place names text through mapping natural language descriptions into types with common features,so that the usability of place names can be enhanced on the basis of maintaining their own semantic characteristics.The features of place names that have been excavated can reflect the natural geography,cultural atmosphere and construction direction of the city.Aiming at solving the problem of sparse features and unbalanced types of short texts of place names,the research exploited the BERT（Bidirectional Encoder Representations for Transformers）to train the word embeddings in the exclusive domain for the content of place names in the chronicle area.The information of chronicles can supplement the lexical features and enhance the ability to extract semantic features from place names.At the same time,the research improved the loss function of BERT and realized high-precision classification of street names.The improved model increased the accuracy of semantic feature mining and provided a guarantee for scientific and objective recognition of the natural and social environment of the city.（2）The paper analyzed the urban development process based on spatio-temporal-semantic feature mining.Based on the semantic mining of place names,we combined the information from both time and space.For typical cities,the evolution of hundreds of years was reproduced from the terms of urban spatial form and urban semantic characteristics.Through the mining of semantic information,the basic resources of urban development and the different development directions and preferences at different stages were reflected.The study took Hangzhou as a typical example to analyze the characteristics of urban development.Taking the 1990 as the boundary,the speed of urban expansion in Hangzhou shows a trend from slow to fast.In terms of spatial pattern,Hangzhou mainly developed around the West Lake the canal in a small area before the founding of the People’s Republic of China.During this period,the expansion direction was restricted by the West Lake,and it mainly developed in the north-south direction.In the early days of the founding of the People’s Republic of China,the layout of the east and west of the city was broken,and the urban space extended westward.After the reform and opening up,the urban construction shifted from being back to the river and facing the lake to the development along the river.Around the 21^st century,the spatial layout evolved into a wider range of east-west expansion and formed a new cross-river grouping pattern.The urban spatial structure has evolved from an initial single-center pattern to a multi-center and multi-circle pattern.In the construction of urban feature,Hangzhou is a typical historical and cultural city,with a long and profound cultural heritage and natural and geographical features of being surrounded by mountains and rivers.The urban development direction after the founding of the People’s Republic of China fully reflects Hangzhou’s emphasis on the unique advantages of historical culture and natural landscapes.In the early days of the founding of the People’s Republic of China,the construction features were mainly focus on landscape and culture.During the turbulent development period,political activities were the mainstay of urban construction.After the reform and opening up,it began to focus on economic development and people’s livelihood construction.Around the 21^st century,Hangzhou has expanded its urban functions with its own cultural advantages,showing a multi-directional comprehensive development trend.High-tech industries,culture,sports,science and education,and tourism are its main development directions.（3）The paper designed an urban development similarity analysis method considering spatial and non-spatial characteristics.The urban development process is expressed as a set of time series including urban spatial morphology and environmental semantic features.The multi-dimensional weighted dynamic time warping method was introduced to solve the problem of mismatched lengths of time series of urban development characteristics.On this basis,ten typical cities in China were selected to conduct similarity analysis and urban clustering on the development process between cities.Through similarity analysis,it was found that Shanghai has unique and distinctive development characteristics,and its urbanization process is greatly influenced by factors of the modern area.Shanghai is inclusive and has absorbed plenty of foreign cultures in the early days of urban construction.Taking advantages of location,Shanghai become a window city that communicates with domestic and foreign countries.Nanjing,Hangzhou,Chongqing,and Xi’an are all famous historical and cultural cities.Such cities have profound cultural accumulation and are supported by multi-industry.There are still some differences in the level of development.Based on similar characteristics and culture accumulation,similar cities can learn from each other’s advanced development experience to assist their own urban planning.Shenyang and Shijiazhuang are both industrial-driven cities,which do not reflect much historical and cultural characteristics in the process of modernization.They focus more on the development of industry and economy.Kunming,Yinchuan and Xining also had historical and cultural accumulation in the early stage,but the overall development level was relatively low,and they belonged to regional comprehensive cities.