A Syntactic Study On The Forms Of Multi-scaled Urban Spatial Network

How are the forms of urban spatial network generated? This is one of the key issues addressed by urban morphological studies.Although various researches have tackled this question from the perspectives of sociology,economy,culture and cognition,it remains important to investigate it from the angle of physical geometry.With the rises of human-focused strategy,network thinking and big-data analysis,the paradigm of studying physical form of urban network has been altered from aesthetic composition to place making and then to spatial networking,from the wholeness of structure to individual experience and then to a combination of both strands,from static form to dynamic system and then to multi-scaled analysis.Considering the national policies,newly issued by Central Urbanism Work Conference,of shifting from the planning preferring urban expansion to the planning limiting urban boundaries and optimizing spatial structure,to tackle the question of how to enhance the quality of the forms of space network,with the aims of optimizing urban structure and implementing fine-scaled design and management,is becoming a necessary task?.This dissertation starts with reviewing the relative theories on spatial form,complex network,big-data,as well as the studies of space syntax on physical forms,in order to clarify smaller questions developed from the big question focusing on the role of scale in spatial structuring.How is each street connected into the surroundings with an increase of scale? Why is such street network,generated from the bottom to the up,not an evenly intensified grid? Why does cul-de-sac appear? Are there any multi-scaled laws of complex networks? And how do the different types of multi-scale structuring coordinate to from static structures? The dissertation then proposes four themes,namely full-scaled embeddedness process,multi-scaled spatial efficiency,multi-scaled thickness of networking,as well as multi-scaled optimization of location choice.It identifies the two-parameter Weibull distribution function can be used to describe the formation of urban network,one parameter focusing on integration and another looking into the change rate of node count.It offers the constricted mechanism of agglomeration,decentralization.Based on which,it solves a paradox of total depth and choice and suggests the concept of multi-scaled space efficiency aiming to explain the clustering coefficient of 50 cities across the world.Then,it illustrates a series of the patterns of multi-scaled space efficiency,with an aim of identifying the emergency of urban structures sustained by interaction between scales.Finally it,by analyzing the POI data representing urban functions,proposes an idea of functional spatiality that urban functions seek locations according to space efficiency.Base on the above studies,the dissertation suggests a conceptual framework of describing the forms of urban spatial network,in which geometric features of urban networks can be explained from three dimensions of agglomeration,decentralization and scale.This basic study might make a step towards contributing to urban from studies in China.