Investigation On The Evaluation And Optimization Method Of Intensive Urban Block Forms Based On Digital Technology

The construction of intensive city is an important guarantee to promote the sustainable development of cities in China in the future.As the basic unit of urban land and form management,the scientific management and control of block form plays a key role in the intensive development of urban overall space form.At present,the research on block form in China is still in the exploratory stage.Although a large number of scholars have gradually tried to break through the traditional urban design method based on aesthetic experience and subjective value judgment,and provide more rational development principles and objectives for block form,there are still relatively few researches that can really provide reasonable decision-making for the intensive development of block form,which is in urgent need We have made further breakthroughs in theoretical construction and application technology.In recent years,with the rapid development of big data,artificial intelligence technology and other computing science in various fields,digital urban design,which combines quantitative calculation,objective evaluation and intelligent optimization,will become an important direction to solve this research topic,and will provide more scientific and efficient spatial decision-making for intensive urban block shape management and control,as well as urban sustainable development.Under this background,this paper takes the urban block as the research object,with the purpose of promoting the development of intensive urban block.Under the perspective of urban design discipline,from the theoretical framework to the technical method,and then to the specific application,it gradually discusses the intensive evaluation and optimization of urban block form,as well as the application method of digital technology in it.At the theoretical level,the study starts from the connotation of the concept of intensity,and analyzes the concept of intensive block form from the perspective of spatial production relationship.Secondly,analyzes the dynamic mechanism of urban block form development,and understands the spatial interaction and development law between the development of block form and urban spatial system.Thirdly,discusses the internal logic of the intensive envaluation and optimization method based on the above,including intensive evaluation logic based on input and output efficiency,and block form optimization logic based on learning developing laws,which establishes theoretical basis for the follow-up application of deep learning.Finally,based on the quantitative analysis of urban morphology and the discussion of urban design management and control,two analysis dimensions-plane shape,three-dimensional shape are established.At the technical level,this paper first discusses the rise and development of digital urban design,and then expounds the technical methods and related principles applied in the research.The main technical applications include four aspects: block shape collection and data analysis,intensive evaluation model based on data envelopment analysis,and shape optimization based on deep learning and the optimization result statistics based on Bayesian statistics.The corresponding computing and analysis platforms are: urban open source information and grasshopper programming technology based on cadmapper and Google Earth,Deap 2.1 for data envelopment analysis,Spyder platform for writing and running deep learning model,and Bayesian statistics integrated in SPSS version 25.0.At the application level,206 blocks in the old urban area of Nanjing are selected as research cases to apply the theoretical basis and technical methods.In the study of plane form,an index system including six output indexes and five input indexes is established.From the intensive evaluation of data envelopment analysis to the shape indexes optimization by deep learning technology,and then to the statistical calculation based on Bayesian statistics,the optimization of output indexes of 109 non intensive blocks is realized.In the study of stereo morphology,a method of stereo morphology description based on vertical spatial density is proposed,and the relevant data collection and statistics are carried out through the program of grasshopper.On this basis,combined with the optimization calculation results in plane form,the development density of 109 non intensive blocks at the height of 24 m,50m,100 m,150m and 200 m is further optimized by using the deep learning method,so as to realize the optimization and control of the three-dimensional space form.Although urban block is the component unit of urban form,its research perspective is not limited to the block itself,but needs systematic analysis,evaluation and optimization from the overall level of the city.At the end of this paper,the problems to be solved in this study are discussed and suggestions and prospects are put forward.Although the block is only the basic unit of city composition,it has great research potential.As the basic medium of urban form and architectural development,it not only affects the land development and architectural form internally,but also influences the development of urban overall spatial form from unit to overall,from micro to macro level.Taking the research of intensive urban block form as an opportunity,it can not only provide the research basis for the future urban inefficient land reuse and urban renewal,but also carry out the relevance research with many perspectives such as urban green space system,urban historical block protection,urban style shaping,etc.,so as to promote the intensive,efficient,harmonious and livable urban sustainable development.