Feijoo Costa, GumersindoGonzález García, SaraRama Caamaño, Manuel2021-10-132021-10-132021http://hdl.handle.net/10347/26994Urban systems can be considered living organisms driven by flows of matter and energy (biophysical approach). In addition, the fact of concentrating many people in a small space also implies socioeconomic aspects of coexistence. Currently 60% of the world's population is concentrated in cities. This makes cities great consumers of natural resources, generating a large amount of greenhouse gas emissions, as well as waste. Therefore, this thesis aims to apply and to develop methodologies to determine and quantify the degree of sustainability that Spanish cities have and thus identify their weaknesses. Therefore, this thesis is intended to serve as support for political leaders when making decisions and to create lines of action to improve and achieve the goal of a sustainable city.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Sustainable CityUrban SystemsLife Cycle AssessmentEnvironmentally Extended Input- Output AnalysisSustainable Development IndicatorsUrban MetabolismMaterias::Investigación::33 Ciencias tecnológicas::3308 Ingeniería y tecnología del medio ambiente::330809 Ingeniería sanitariadoctoral thesisopen access