Visual Landscape Analysis For Urban Mountains Based On Multi-dimensional Digital Models

Urban areas are the major areas of modern social activities,such as commercial activities,political activities,cultural activities and exchange activities.City construction is the crucial engine of China’s modernization drive.China’s urbanization rate grew rapidly over decades since 1978 when Reform and Opening up was first suggested.It is true that the swift growth of urbanization in China has stimulated the social development to some extent,but it brings many problems as well.One of the urban problems is the losing of urban images because of improper urban planning or design strategies.Especially the urban natural landscape,such as urban mountains,has been visually vanishing under intensive and under-controlled constructions.To address the current visual problems in China’s urban spaces,this research proposed a visual analysis method for thoroughly analyzing the visual properties in urban environments.This visual analysis method is using multiple digital technologies and contains multi-scaled analysis processes.The proposed method could also provide quantitative results for describing the urban visual spaces,thereby helping to make better decisions.This research takes urban mountains as the main research project,uses GIS,LiDAR and other digital technologies to construct a quantitative analysis method for urban mountain visual landscapes.This quantitative analysis method is based on multi-dimensional digital models which combining 2D urban models with 3D urban models.The proposed method could provide quantitative visual properties for large-scaled,medium-scaled and micro-scaled urban spaces,these quantitative properties could reveal the inner visual structures of urban environments.A visibility analysis algorithm is developed by using a hybrid model,the hybrid model combines LiDAR point clouds with vector solid models.The hybrid model based visibility algorithm can evaluate the visual effect of the urban vegetation.The case of Zijin Mountain,Nanjing is selected for further investigation.The proposed method was conducted on the case to analyze visual properties of both Zijin Mountain and urban open spaces which are visible to the mountain.The LiDAR point cloud data of south Yueyahu Park was collected for constructing a hybrid point cloudsolid model.Several visual characters were founded by performing a new visibility algorithm in the hybrid model.And then several preliminary strategies were proposed for shaping a better visual landscape based on the results.There are 4 main innovative aspects in this study:1)Proposing a quantitative visual analysis method by introducing multi-dimensional models.This method can provided visual properties for describing the objective visual spaces,as well as comprehensive visual results for a large-scale urban space.2)Taking urban mountain as the research object,and using proposed analysis method to thoroughly explore the inner visual properties of the urban mountain within urban spaces.3)Presenting a visibility algorithm based on the hybrid point cloud-solid model,this model can evaluate the visual impact of urban vegetation which is often overlooked in traditional analysis.4)Building a multi-scaled visual analysis process.This study used Nanjing as the case to perform proposed method and served several urban management strategies based on quantitative results.There contains more than 115,000 characters,100 figures(including appendix)and 29 tables in this thesis.