Browsing by Keyword "CityGML"
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Item The Application of LiDAR Data for the Solar Potential Analysis Based on Urban 3D Model(Multidisciplinary Digital Publishing Institute (MDPI), 2019-10) Prieto, Iñaki; Izkara, Jose Luis; Usobiaga, ElenaSolar maps are becoming a popular resource and are available via the web to help plan investments for the benefits of renewable energy. These maps are especially useful when the results have high accuracy. LiDAR technology currently offers high-resolution data sources that are very suitable for obtaining an urban 3D geometry with high precision. Three-dimensional visualization also offers a more accurate and intuitive perspective of reality than 2D maps. This paper presents a new method for the calculation and visualization of the solar potential of building roofs on an urban 3D model, based on LiDAR data. The paper describes the proposed methodology to (1) calculate the solar potential, (2) generate an urban 3D model, (3) semantize the urban 3D model with different existing and calculated data, and (4) visualize the urban 3D model in a 3D web environment. The urban 3D model is based on the CityGML standard, which offers the ability to consistently combine geometry and semantics and enable the integration of different levels (building and city) in a continuous model. The paper presents the workflow and results of application to the city of Vitoria-Gasteiz in Spain. This paper also shows the potential use of LiDAR data in different domains that can be connected using different technologies and different scales.Item Climate change risk assessment: A holistic multi-stakeholder methodology for the sustainable development of cities: A holistic multi-stakeholder methodology for the sustainable development of cities(2021-02) Gandini, Alessandra; Quesada, Laura; Prieto, Iñaki; Garmendia, Leire; Tecnalia Research & Innovation; LABORATORIO DE TRANSFORMACIÓN URBANACities are at risk due to global climate change, increasing both the frequency and the intensity of storms and extreme precipitation, sea-level rise, and other extreme weather events. Disaster risk reduction and adaptation to climate change should include a holistic and multi-scale perspective, to address the challenges of sustainable urban development and the conservation of the cultural value of our cities. In this research, an integral multi-stakeholder methodological approach is presented for risk assessment, supported by a data-collection and analysis strategy and a multi-scale urban model based on CityGML. A method of sampling buildings is presented together with the necessary data analysis, in order to perform the analysis at city scale. The methodology is implemented in Donostia- San Sebastián (northern Spain), a city located alongside a river estuary on the coastline. A sample of 2262 buildings are analyzed with varied characteristics at risk of extreme precipitation and/or storm surges and sea-level rise. The results demonstrated the effectiveness of the methodology at generating a unique risk index through a balance between the resources for data collection and the accuracy of the results, supported by a graphical 3D representation to facilitate results interpretation, and the subsequent evidence-based decision-making for prioritizing sustainable interventions.Item A continuous deployment-based approach for the collaborative creation, maintenance, testing and deployment of CityGML models(2017-10-26) Prieto, Iñaki; Izkara, Jose Luis; Béjar, Rubén; Tecnalia Research & Innovation; LABORATORIO DE TRANSFORMACIÓN URBANAGeoreferenced 3D models are an increasingly common choice to store and display urban data in many application areas. CityGML is an open and standardized data model, and exchange format that provides common semantics for 3D city entities and their relations and one of the most common options for this kind of information. Currently, creating and maintaining CityGML models is costly and difficult. This is in part because both the creation of the geometries and the semantic annotation can be complex processes that require at least some manual work. In fact, many publicly available CityGML models have errors. This paper proposes a method to facilitate the regular maintenance of correct city models in CityGML. This method is based on the continuous deployment strategy and tools used in software development, but adapted to the problem of creating, maintaining and deploying CityGML models, even when several people are working on them at the same time. The method requires designing and implementing CityGML deployment pipelines. These pipelines are automatic implementations of the process of building, testing and deploying CityGML models. These pipelines must be run by the maintainers of the models when they make changes that are intended to be shared with others. The pipelines execute increasingly complex automatic tests in order to detect errors as soon as possible, and can even automate the deployment step, where the CityGML models are made available to their end users. In order to demonstrate the feasibility of this method, and as an example of its application, a CityGML deployment pipeline has been developed for an example scenario where three actors maintain the same city model. This scenario is representative of the kind of problems that this method intends to solve, and it is based on real work in progress. The main benefits of this method are the automation of model testing, every change to the model is tested in a repeatable way; the automation of the model deployment, every change to the model can reach its end users as fast as possible; the systematic approach to integrating changes made by different people working together on the models, including the possibility of keeping parallel versions with a common core; an automatic record of every change made to the models (who did what and when) and the possibility of undoing some of those changes at any time.Item A holistic and multi-stakeholder methodology for vulnerability assessment of cities to flooding and extreme precipitation events(2020-12) Gandini, Alessandra; Garmendia, Leire; Prieto, Iñaki; Álvarez, Irantzu; San-José, José-Tomás; Tecnalia Research & Innovation; LABORATORIO DE TRANSFORMACIÓN URBANAOver recent years, the frequency and intensity of torrential rain and flooding events linked to climate change have been impacting on cities throughout the world. Adaptation to climate change must therefore be integrated into urban planning and coupled with sustainable urban development and conservation policies. To do so, a good understanding of the vulnerability of cities to these extreme events is necessary, lending special attention to the specifics of the different urban areas, such as historic city centres. In the present study, a vulnerability evaluation methodology is presented for cities against extreme rainfall and flooding, which follows a holistic and multi-stakeholder approach, integrating architectural, socio-economic, and cultural perspectives, that supports evidence-based decision-making for the sustainable development of the agents that intervene in the process. The MIVES method, based on a multiple criteria decision-analysis process and a CityGML-based data model are used for that purpose, with which a process for capturing, evaluating, and representing information in an objective, organized, and systematic way has been developed. These advantages are demonstrated through the application of that process to a case study in Donostia-San Sebastián (northern Spain), located on a river estuary in front of the sea, with a wide diversity of building styles.Item Multi-scale urban data models for early-stage suitability assessment of energy conservation measures in historic urban areas(2018-04-01) Egusquiza, Aitziber; Prieto, Iñaki; Izkara, Jose Luis; Béjar, Rubén; LABORATORIO DE TRANSFORMACIÓN URBANA; Tecnalia Research & InnovationThe demand for improving the energy performance of buildings located in the historic districts of cities is as high as the current demand in other city districts. The need to reduce energy consumption and improve the comfort of inhabitants is compounded by the need to preserve an environment of heritage value. The selection of rehabilitation strategies at urban scale offers significant benefits, but makes the process long and costly. Therefore, methods or tools are necessary to establish a rapid assessment that facilitates strategic decision making and a deeper analysis of a reduced number of alternatives.This paper describes a method that supports decision making regarding the suitability of Energy Conservation Measures (ECMs) in historic districts at early stages. The method considers the improvement of the energy performance of buildings as a positive impact, balanced with the negative impacts that the implementation of ECMs could produce. A CityGML-based urban model allows the automation of a multi-scale assessment for different ECMs and provides possible global energy demand reductions. This method, combined with an economic evaluation, can be used by decision makers for large-scale energy retrofitting. The applicability of the method is demonstrated through implementation in the historic city of Santiago de Compostela.