This article presents a study based on the outputs from the LUISA Territorial modelling platform (Joint Research Centre of the European Commission) focused on regional and local future projections of land abandonment between 2015 and 2030. Spain is taken as representative of one of the countries highly affected by agricultural land abandonment in the European Union. The most relevant factors driving land abandonment (biophysical, agroeconomics, farm structure and demographic) are described and mapped. Results from the analysis reveal that the Galicia region, northern Spain (Asturias, Cantabria, Gipuzkoa, Bizkaia), north-eastern Spain (Aragón region), central Pyrenees/Ebro basin (Huesca, Navarra, Lleida) and south-eastern Spain (Murcia, Almería, Alicante, Málaga) are expected to undergo important abandonment processes. The study also concludes that land abandonment within mountainous, high nature value farmland and Natura 2000 areas is lower compared to the outside area without conservation and protection measures.

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.

Indoor air quality is a characteristic that depends on air pollutants inside a building and that can be affected by different ventilation strategies. There is strong evidence linking poor indoor air quality (IAQ) and harmful health effects, especially on vulnerable collectives, such as children in schools. Due to this concern, this work aims to provide guidance on the design of highly efficient ventilation strategies to improve the air quality of schools’ classrooms. For this, IAQ monitoring has been carried out in eight educational in real conditions centres using CO₂ concentration as an IAQ indicator. Variables such as the presence of students and their number, activity developed in the classroom and ventilation strategy used together with break time duration have been also recorded to analyse their influence on CO₂ concentration levels. Concluding results have allowed us to determine the maximum number of students allowed in a closed room to maintain CO₂ levels at normal concentrations and the time needed to reduce these CO₂ levels depending on the ventilation strategy adopted. Moreover, it has been discussed how surrounding school conditions (pollution or noise) and the building isolation are impacting the final IAQ in the classrooms studied.

Some of the most powerful spatial analysis software solutions (Oracle, Google Earth Engine, PostgreSQL + PostGIS, etc.) are currently performing geometric calculations directly on the ellipsoid (a quadratic surface that models the earth shape), with a double purpose: to attain a high degree of accuracy and to allow the full management of large areas of territory (countries or even continents). It is well known that both objectives are impossible to achieve by means of the traditional approach using local mathematical projections and Cartesian coordinates. This paper demonstrates in a quantitative methodological way that most of the spatial analysis software products make important deviations in calculations regarding to geodesics, being the users unaware of the magnitude of these inaccuracies, which can easily reach meters depending on the distance. This is due to the use of ellipsoid calculations in an approximate way (e.g., using a sphere instead of an ellipsoid). This paper presents the implementation of two algorithms that solve with high accuracy (less than 100 nm) and efficiently (few iterations) two basic geometric calculations on the ellipsoid that are essential to build more complex spatial operators: the intersection of two geodesics and the minimum distance from a point to a geodesic.

Today, about 55% of the world population lives in cities and this is foreseen to increase to 68% by 2050. The urban activities of such a large number of people in relatively small spaces can make the air quality levels in cities harmful to human health. For this reason, the European Union (EU) has established a regulatory framework to control and improve air quality levels in cities (Directive 2008/50/EC) by defining a number of fixed stations and other requirements. The aim of this work is to evaluate the air quality reported by the official fixed stations via the installation of a complementary mobile network of air quality based on passive dosimetry of NO₂ measurement during the period 2017–2019. In this study, Valencia (Spain) is selected as a representative European city with seven fixed stations and a network of 424 passive dosimetry sensors distributed throughout the city. In addition, an index of impact of pollutant on population is developed to optimize the locations of air quality stations among neighbourhoods across the city based on the levels of pollution measured by mobile sensors and the population directly affected. The results obtained show that 43.7% of mobile sensors in Valencia exceeded the limit value established by the EU Directive as well as by the World Health Organization during the assessment period. This indicates that the air quality levels offered by the fixed stations are neither representative nor reliable for the air quality monitoring of the city. Thus, the fixed stations currently operating do not provide reliable information on the areas of the city where the majority of the population breathes air with the highest level of pollution. Specifically, the results show that 34.6% of citizens live in areas with an average annual value above the limit recommended for the protection of human health.