Open-Source MAP Data Based Agglomeration Of Commercial Facilities Of Harbin

The way of urban development and construction in China is moving from extensive to meticulous.Under this trend,urban planning is also developing towards quantitative,refined and scientific direction.The allocation of urban space resources is main content of urban planning field.However,in China,the researches in this field are still in its infancy and lack of quantitative methods.Commerce is the core function of a city.The layout of commercial facilities is one of the essential questions of contradiction between land use and people demands.With the development of society,commerce involves various industries and massive facilities.In this complex and rapid changing condition,it is difficult for urban planners to comprehensively and precisely understand the distribution of commercial facilities.It leads to the difficulty of solving dynamic,delicate and quantitative problems in urban management and urban planning.Commercial facilities aggregate in cities.The identification and classification of commercial centers are common concerns of scholars.However,there are some limitations in the elaboration of identifying,the selection of variables in classification,and the extensibility of methods.This study based on open-source maps POIs data which is subdivided by commercial industries.Firstly,the agglomeration effect of industries are measured by the global and local agglomeration indices.Secondly,the modified adaptive spatial clustering algorithm based on Delaunay triangulation(ASCDT)is used to identify industry centers.Thirdly,the k-means clustering algorithm is used to classify the industry centers into hierarchy by the size variables.Then,we identify commercial centers by clustering industry centers.Finally,the hierarchy of commercial centers is classified according to four variables including the quantity of commercial POIs,the area of commercial centers,the abundance of independent industries and the hierarchy of industry centers' groups.The approach proposed in this study is based on open-source POIs data and adaptive algorithm.Thus,the approach has a wide range of extensibility.The above approach is applied to the main urban area of Harbin,China.There are 19 of the 44 industries have agglomeration effect.And the industry centers of these 19 industries have different characteristics of distribution.The commercial centers are classified into four levels including 2 centers belonging to the highest IVlevel,10 centers belonging to III-level,33 centers belonging to II-level and 329 centers belonging to the lowest I-level.Comparing the spatial distribution of these commercial centers with the current situation of urban land use,it is found that commercial centers are mainly distributed in residential land and commercial land.Comparing the location and hierarchical structure of commercial centers with the planning of commercial centers in the urban master plan,it is found that the layout of commercial centers in urban master planning mainly considers the balance of each urban district while the actual distribution of commercial centers is uneven.This study explores and validates the possibility of using open-source map data to mine spatial distribution characteristics of urban functional facilities.The methods and results of this study can provide information to support qualitative,quantitative and positioned researches of commercial facilities planning.