• Energy Research

This paper aims to evaluate the accessibility to urban mobility services with high spatial resolution. The methodology identifies the percentage of the population living within walking distance of the different public transport and shared mobility systems. The motivation for this study stems from the importance of understanding and improving sustainable urban mobility, as well as the need to evaluate the effectiveness of transportation infrastructure. The study involved creating buffers from each station following the road network according to urban design to identify areas within a 5-min walk, then calculating the affected population by age range within these zones to ensure equity. This method determined the percentage of the population with access to available mobility services: bike renting, urban bus, intercity bus, metro, taxi, tram and train. The application of the methodology to the Valencia case study underscores the overall strong accessibility of mobility services. The main results indicate access to mobility services for 99.98% of the total population of the city. The accessibility percentages for specific mobility services vary, with urban bus and bike renting showing high accessibility, while train and tram services exhibit lower accessibility rates. Additionally, the study extends its assessment to the peri-urban area, revealing a global access percentage of 46.33%. In conclusion, this study allows us to identify areas with lower accessibility and help to improve the sustainability of urban mobility. These findings can aid urban planners and policymakers by providing valuable insights into the city’s mobility network’s strengths and areas for improvement.

Buildings have become a key source of greenhouse gas (GHG) emissions due to the consumption of primary energy, especially when used to achieve thermal comfort conditions. In addition, buildings play a key role for adapting societies to climate change by achieving more energy efficiency. Therefore, buildings have become a key sector to tackle climate change at the local level. However, public decision-makers do not have tools with enough spatial resolution to prioritise and focus the available resources and efforts in an efficient manner. The objective of the research is to develop an innovative methodology based on a geographic information system (GIS) for mapping primary energy consumption and GHG emissions in buildings in cities according to energy efficiency certificates. The developed methodology has been tested in a representative medium-sized city in Spain, obtaining an accurate analysis that shows 32,000 t of CO2 emissions due to primary energy consumption of 140 GWh in residential buildings with high spatial resolution at single building level. The obtained results demonstrate that the majority of residential buildings have low levels of energy efficiency and emit an average of 45 kg CO2/m2. Compared to the national average in Spain, this obtained value is on the average, while it is slightly better at the regional level. Furthermore, the results obtained demonstrate that the developed methodology is able to directly identify city districts with highest potential for improving energy efficiency and reducing GHG emissions. Additionally, a data model adapted to the INSPIRE regulation has been developed in order to ensure interoperability and European-wide application. All these results have allowed the local authorities to better define local strategies towards a low-carbon economy and energy transition. In conclusion, public decision-makers will be supported with an innovative and user-friendly GIS-based methodology to better define local strategies towards a low-carbon economy and energy transition in a more efficient and transparent way based on metrics of high spatial resolution and accuracy.

[EN] In the current scenario of climate emergency and energy transition, leveraging knowledge from interdisciplinary fields like the food-water-energy nexus is crucial. Traditional irrigation canals, an integral part of agricultural sustainability, offer untapped potential for small-scale hydropower, providing a decentralized and reliable electricity source. This study estimates the potential for small-scale hydropower production in a medium-scale irrigation system in the Valencia province (Spain). Relevant parameters obtained from local sources (head, water flow, irrigation regimes, etc.) were analysed to select the most appropriate turbine. A total of 8 mills were considered for this branch of the irrigation network. Potential power installable and energy production were estimated using 30 years of historical water flow data from in situ measurements. A maximum of 750 MWh/year for the highest head mill was calculated for the year with the highest water flow (2010). For the same year, the total production for all mills together reached nearly 5 GWh/year. These results are consistent with similar case studies in the literature and highlight the untapped capacity of the irrigation network for potential future practical projects. Discussions on the application of the energy produced consider two scenarios: electricity self-consumption and sale to the grid, and hydrogen production for local industrial use. Both scenarios show significant benefits (economic and energy) for the potential installation of hydropower systems. The mitigation potential, particularly for hydrogen production, is shown to depend on the national electricity mix. Opportunities and limitations are considered, highlighting the policy context and the need for further research on economic viability, life cycle assessments, and future climate projections. This work supports decentralized energy models aligned with the EU¿s carbon neutrality goals and emphasizes the significant potential for micro-hydro installations in irrigation canals as part of a sustainable energy mix.

While the Mediterranean basin is foreseen to be highly affected by climate change (CC) and severe forest fires are expected to be more frequent, international efforts to fight against CC do not consider forest fires’ greenhouse gas (GHG) emissions risk and the possibility of its mitigation. This is partly due to a lack of a methodology for GHG risk spatial assessment and consideration of the high value of carbon stocks in forest ecosystems and their intrinsic risk. To revert this, an innovative GHG emission risk model has been developed and implemented in a pilot forest area. This model considers geospatial variables to build up emission vulnerability based on potential fire severity and resistance of a landscape, value at risk and the hazard of a fire occurrence. The results classify low, moderate and high emission risks in the analysed areas. This identification of hotspots allows the prioritisation of fire prevention measures in a region to maximise the reduction of GHG emissions in the case of a fire event. This constitutes the first step in a holistic and consistent CC mitigation that not only considers anthropic GHG sources but also possible GHG emissions by forest fires that can be actively prevented, managed and reduced.

Forest management is an untapped tool, yet to realize its full potential to fight against climate change. The capability of forests to act as carbon sinks makes them a key resource to reduce CO2 concentration in the atmosphere. However, carbon which has been fixed can be suddenly emitted again as a consequence of disturbances such as pests or wildfires. Mediterranean plant phenology, climatic conditions, and the accumulation of fuel biomass due to abandonment of traditional forest uses generate a scenario prone to large wildfires and consequently large greenhouse gases (GHG) emissions. The abandonment could be offset by considering the economic value of forest ecosystem services, principally carbon fixation. Nevertheless, currently existing forest carbon markets consider only anthropogenic fixation based on a business as usual scenario without disturbances that cannot be applied to Mediterranean forest reality. Thus, a methodology to monetize carbon fixed has been developed and applied. A range between 55.5 and 250 million € produced by the monetization of 16.5 million potential carbon credits has been obtained based on anthropogenic avoided emissions produced over a 10 year-period. Thereby, the potential for offsetting emissions of the pilot region was between 1.2% and 5.6% of total diffuse GHG emissions. Consequently, sustainable forest management represents an important opportunity to combat climate change, taking advantage of the margin of improvement that the Mediterranean forests currently have to avoid GHG emissions through forest fire prevention silviculture.

During the period of the COVID-19 pandemic, the air quality reached the best levels to be recorded in large cities in Spain. To analyze and demonstrate this improvement in air quality levels, the evolution of the average nitrogen dioxide (NO2) levels in 78 Spanish cities with more than 50,000 inhabitants during the pre-COVID-19 years (2017–2019), the period of the COVID-19 lockdown, and the post-COVID-19 year (2021) was analyzed. The results show an improvement in the air quality in most of the cities analyzed for 2020 due to the COVID-19 restrictions. In addition, in 2021, without the COVID-19 restrictions, the air quality levels of the largest cities in Spain showed important improvements in terms of NO2 concentration compared to the levels in the pre-COVID-19 years (2017–2019). Nevertheless, in 2021, only 11 cities were below the average annual limit of 10 µg/m3 NO2 established by the World Health Organization (WHO). In addition, no cities with more than 500,000 inhabitants achieved NO2 levels below the WHO limit. Finally, a detailed monthly analysis indicated that the pre-COVID-19 levels were reached again during the last months of the monitored period.

[EN] The Agenda for Sustainable Development 2030 of United Nations is made up of the 17 Sustainable Development Goals (SDGs) that humanity will have to meet by 2030. In achieving the SDGs, green urban areas (GUA) play a fundamental role at the local level as they provide recreational and bioclimatic regulatory functions and act as a carbon sink, as well. Specifically, the GUAs contribute directly to three SDGs: SDG 11 Sustainable cities and communities, SDG 13 Climate Action and SDG 15 Life on land. This paper evaluates direct contribution of GUA to this SDGs with high spatial resolution in the case study of the city of Valencia (Spain). The evaluation carried out has made it possible to make a diagnosis of the quantity and accessibility of GUA at sub-neighbourhood level. The results for SDG 11 show that only 9.23% of the population do not have desirable access to GUA and 2.73% live in areas without easy walking distance access to GUA. On the other hand, the evaluation of SDG 15 shows that each inhabitant has at their disposal 10 m2 of GUA, below the average of cities of more than 250,000 inhabitants in Spain. The high spatial resolution of the evaluation has also made it possible to identify the city areas with the worst access to GUA and the least amount of GUA per inhabitant. In consequence, the results allow determining zones with high potential to improve. Additionally, the quantification of the CO2 fixed by the GUA carried out for the evaluation of SDG 13, shows that the fixed carbon is equivalent to 0.04% of total gross GHG emissions of the city and is 36% higher than the total GHG emissions of the annual fuel consumption of the total fleet in the city. Finally, the monitoring of the indicators applied allows evaluating the evolution of the GUA to improve the sustainable development of the city. We are grateful to the Valencia City Council, specifically the Department of Open Government and Transparency directed by Elisa Valia, through the DataGovernance VLC university chair, for being able to make available much of the data necessary for this research. We are also thankful to the company GreenUrbanData, which provided tech-nical expertise that greatly assisted the research. Finally, we also thank the scientific support of Dr Carolina Perpina and Dr Carlo Lavalle of the Joint Research Centre (JRC) of the European Commission (Directorate B-Growth and Innovation, Territorial Development Unit B3) for their scientific support within the framework of collaboration agreement (No. 35930) to contribute to analyse field of urban sustainability indicators, where Valencia acts a City Lab under the framework of the EU Com-munity of Practice on CITIES. Funding sources This work was supported by the Regional Agency of Innovation of Valencia/Spain (AVI) in the project TRUST "Sustainable urban transition through metrics for public decision based on big data" (INNEST00/18/005) .