Creation and Spatial Analysis of 3D City Modeling based on GIS Data

The 3D city model is one of the crucial topics that are still under analysis by many engineers and programmers because of the great advancements in data acquisition technologies and 3D computer graphics programming. It is one of the best visualization methods for representing reality. This paper presents different techniques for the creation and spatial analysis of 3D city modeling based on Geographical Information System (GIS) technology using free data sources. To achieve that goal, the Mansoura University campus, located in Mansoura city, Egypt, was chosen as a case study. The minimum data requirements to generate a 3D city model are the terrain, 2D spatial features such as buildings, landscape area and street networks. Moreover, building height is an important attribute in the 3D extrusion process. The main challenge during the creation process is the dearth of accurate free datasets, and the time-consuming editing. Therefore, different data sources are used in this study to evaluate their accuracy and find suitable applications which can use the generated 3D model. Meanwhile, an accurate data source obtained using the traditional survey methods is used for the validation purpose. First, the terrain was obtained from a digital elevation model (DEM) and compared with grid leveling measurements. Second, 2D data were obtained from: the manual digitization from (30 cm) high-resolution imagery, and deep learning structure algorithms to detect the 2D features automatically using an object instance segmentation model and compared the results with the total station survey observations. Different techniques are used to investigate and evaluate the accuracy of these data sources. The procedural modeling technique is applied to generate the 3D city model. TensorFlow & Keras frameworks (Python APIs) were used in this paper; moreover, global mapper, ArcGIS Pro, QGIS and CityEngine software were used. The precision metrics from the trained deep learning model were 0.78 for buildings, 0.62 for streets and 0.89 for landscape areas. Despite, the manual digitizing results are better than the results from deep learning, but the extracted features accuracy is accepted and can be used in the creation process in the cases not require a highly accurate 3D model. The flood impact scenario is simulated as an application of spatial analysis on the generated 3D city model. Doi: 10.28991/CEJ-2022-08-01-08 Full Text: PDF

Walkable City and Military Enclaves: Analysis and Decision-Making Approach to Support the Proximity Connection in Urban Regeneration

Accessibility and urban walkability are the cornerstones of urban policies for the contemporary city, which needs to be oriented towards sustainable development principles and models. Such aims are included in the objectives of the 2030 Agenda, as well as in the ambitious objectives of the ‘European Green Deal’. These concepts are closely linked to the paradigm of a sustainable city—livable, healthy and inclusive—based on a system of high-quality public spaces and on a network of services and infrastructures, both tangible and intangible, capable of strengthening and building new social, economic and environmental relationships. It is necessary to recognize potential opportunities for connection and permeability in consolidated urban environments. These are very often fragmented and are characterized by enclaves of very different kinds. Ghettoes and gated communities, old industrial plants and military installations and facilities, to cite a few, represent examples of cases where closures on urban fabrics are realized, impeding full walkability and accessibility. Within such a framework, the present research is aimed at focusing on a particular set of enclaves, such as those represented by the military sites being reconfigured to civilian use, a phenomenon that characterizes many urban areas in the world; in Europe; and in Italy, in particular, given the recent history and the Cold War infrastructure heritage. In such a sense, the city of Cagliari (Sardinia Island, Italy) represents an interesting case study as it is characterized by the presence of a series of military complexes; real ‘enclaves’ influencing the proximity connections; and, more generally, walkability. Building on previous research and analysis of policies and projects aimed at reintroducing, even partially, this military asset into civilian life (Green Barracks Project (GBP)-2019), this paper proposes and applies a methodology to evaluate the effects of urban regeneration on walkability in a flexible network logic, oriented to the ‘15 min city’ model or, more generally, to the renewed, inclusive, safe “city of proximity”, resilient and sustainable.

Polish National Cittaslow Network: assessment of cities’ membership in the network

Motivation: The Polish National Cittaslow Network associates 31 members and is the second most biggest national network of slow cities in the world. The network is developing very dynamically. Therefore, it is important to observe this relatively new and not fully recognized process of implementing the slow city model in Polish cities, and to assess the effects of cities’ membership in this network. Aim: The aim of the study was to evaluate effects of the membership of cities in the Polish National Cittaslow Network. The effects were assessed on the basis of a comparative analysis of the results of certification carried out before a city accessed the network with the results of recertification, carried out 5 years into its membership. A diagnostic survey method was also used in the study. Results: The research shows that already in the first five years of the membership in the network, the cities have undertaken many activities to enhance their appeal as a tourist destination, promote local products and protect the historic and cultural heritage. The cities have completed many revitalisation projects. New tourist trails, bicycle paths and recreational areas have been created. Undoubted, the membership in the Cittaslow network has generated many benefits to the cities. This is reflected by the higher degree of the fulfilment of the certification criteria by all cities. This is also confirmed by the results of a diagnostic survey conducted among the mayors of member cities.

Modelling Building Shadows on Rooftop Generating 3D City Model

3D city models enable us to gain a better grasp of how various city components interact with one another. Advances in geosciences now allow for the automatic creation of high-quality, realistic 3D city models. It is not limited to visualization and navigation, however, also for shadow and solar potential analysis. Solar radiation is an example of a 3D GIS tool that is in high demand. The calculation of solar radiation that reaches 3D objects can be simple, but the shadow effect of nearby buildings is a considerably more challenging issue because some facades or roofs are only partially shadowed. The present study is analyzed into two approaches. The first approach is considered as Visualization (client-side) approach to visualize the 3D city models on the website using NodeJS and CesiumJS. The second approach is considered as Analyzation (Server-side) approach to analyze the solar potential using python for faster processing and deeming the future development aspects.

Modelling Buildings in CityGML LOD1: Building Parts, Terrain Intersection Curve and Address Features

3D city models integrate heterogeneous urban data from multiple sources in a unified geospatial representation, combining both semantics and geometry. Although in the last decades, they are predominantly used for visualization, today they are used in a large range of tasks related to exploration, analysis, and management across multiple domains. The complexity of urban processes and the diversity of urban environment bring challenges to the implementation of 3D city models. To address such challenges, this paper presents the development process of a 3D city model of a single neighborhood in Sofia city based on CityGML 2.0 standard. The model represents the buildings in LOD1 with a focus on CityGML features of related to the buildings like building part, terrain intersection curve and address. Similar building models of 18 cities provided as open datasets are explored and compared in order to extract good modeling practices. As a result, workflows for generation of 3D building models in LOD1 are elaborated and improvements in the feature modeling are proposed. Two options of building model are examined: modeling of a building as a single solid and modeling of a building with separate building parts. Finally, the possibilities for visualization of the model in popular platforms such as ArcGIS Pro and Cesium Ion are explored.

Sustainable Urban Transport—Why a Fast Investment in a Complete Cycling Network Is Most Profitable for a City

The development of safe cycling as a mode of transport is an important objective of the transformation towards sustainable mobility in European cities. A significant number of European cities are faced with the need to implement the assumptions of the European Green Deal, of which the promotion of sustainable urban transport is a part. The article presented a simulation of the Perfect Cycling City Model in real conditions that inspired the design of two scenarios for the fast development of bicycle routes in a key transport network area in Warsaw. Scenario 1 assumes building subsidiary bicycle routes and links between the main routes. In Scenario 2, the development of all optimal cycling links at the local level is assumed. An increase in cycling participation is expected in both scenarios. The comparison of projected costs of each scenario indicated that building a complete network of connections is more profitable in terms of increased cycling participation and could counter the dominance of private car use. For this to happen, measures encouraging individuals combined with improved safety and convenience of cycling around the city must be undertaken.

Political Effects of Digital Transformation of Urban Governance (On the Example of Moscow)

The paper is devoted to the study of particular political effects of digitalization of urban governance in the Russian Federation. Based on the concept of «surveillance capitalism» and research on the digital transformation of public administration, the authors analyzes the structure and logic of functioning of the «smart city» model using the example of Moscow. Based on the material of street protests, the political effects of the use of digital infrastructure by the city authorities, in particular, camera systems with face recognition technologies, are examined. The study of the Russian situation correlates with the latest decisions of the United Nations (UN) Human Rights Council and the European Union’s initiatives to control remote biometric recognition technologies.

SEMI-AUTOMATIC GENERATION OF AN LOD1 AND LOD2 3D CITY MODEL OF TANAUAN CITY, BATANGAS USING OPENSTREETMAP AND TAAL OPEN LIDAR DATA IN QGIS

3D city models have found purpose beyond simple visualization of space by serving as building blocks of digital twins and smart cities. These are useful to urban areas in the Philippines through diversified applications: urban planning, disaster mitigation, environmental monitoring, and policy making. This study explored the use of free and open-source software to generate an LOD1 and LOD2 3D city model of Tanauan City, Batangas using building footprints from OpenStreetMap and elevation models from Taal Open LiDAR data. The proposed approach consists of GIS-based methods including data pre-processing, building height extraction, roof identification, building reconstruction, and visualization. The study adopted methods from previous studies for building detection and from Zheng et al. (2017) for LOD2 building reconstruction. For LOD1, a decision tree classifier was devised to determine the appropriate height for building extrusion. For LOD2, a model-driven approach using multipatch surfaces was utilized for building reconstruction. The workflow was able to reconstruct 70.66% LOD1 building models and 55.87% LOD2 building models with 44.37% overall accuracy. The RMSE and MAE between the extracted heights from the workflow and from manual digitization has an accuracy lower than 1 m which was within the standards of CityGML. The processing time in test bench 1 and test bench 2 for LOD1 took 00:12:54.5 and 00:09:27.2 while LOD2 took 02:50:29.1 and 01:27:48.2, respectively. The results suggest that the efficient generation of LOD1 and LOD2 3D city models from open data can be achieved in the FOSS environment using less computationally intensive GIS-based algorithms.

Heaven, Earth and Humans: Concept and Processes of Urban Vertical Regeneration

<p><b>Rapid urbanisation, industrialisation, and capitalist developments have changed human values to be driven by materialistic developments instead of ecological developments. This has caused ecological and social crises visible in the urban fabric. There is an urgent need for us to address the question of how can we develop lifestyles that are truly holistic and able to regenerate well-being of humans and it's environments without external helps.</b></p> <p>This thesis explores the interrelationships of feng shui and regenerative development. It attempts to show the recognition of feng shui as an integral to regenerative development that can regenerate urban environment and achieves humans' well-being and harmony with nature. The thesis believes it will need to first remedy urban areas in order to regenerate the rest of the earth. It will explore the process of regeneration from micro to macro levels using feng shui and regenerative development, where it seeks to regenerate the city holistically as a whole.</p> <p>I propose that feng shui becomes an intrinsic model for regenerative development. This discipline is able to solve ecology degradation issues, to provide awareness and realisations of the intrinsic values of cities, and act as a paradigm shift towards achieving regenerative development. This thesis also propose that medium-rises compact city model, which integrate regenerative development and feng shui principles, as a better solution to solve densification of urbanisation compared to building high-rises and skyscrapers.</p>