Miguel Calixto López-Gordillo’s research while affiliated with University of Seville and other places

In this manuscript, there were performed simulations of the evolution of the surface temperature for each of the two hemispheres of Iapetus. This icy moon of Saturn shows the most differentiated albedo dichotomy of the Solar System. The dark leading side has a lower albedo than the bright trailing side. Spectral data on the visible light reveal the existence of two types of materials on the surface. The darkening in the leading side is thought to be due to the presence of organic material and carbonaceous compounds on the surface, while the trailing side is covered by water ice due to migration processes from the dark side. On airless bodies like Iapetus, the surface escape speed is greater than the speed of water molecules, resulting in the retention of a H2O atmosphere that allows some species to diffuse through it. Results showed a slow yet steady increment of temperatures for both sides, with a steeper slope for the dark hemisphere. It was also simulated how much energy can be accumulated on both sides and the consequences of that. Finally, we calculated the diffusion coefficients for ammonia, methane, and water ice. The results allowed us to infer how these compounds could evolve over time.

Numerous drylands worldwide have experienced degradation of both soil and vegetation in proximity to watering areas. Degradation can be observed in satellite imagery as fading radial brightness belts extending away from the water sources. The main objective of this study was to examine the spatio-temporal patterns of land degradation and rehabilitation in the drylands of the southeast Iberian Peninsula. The brightness index of tasseled cap was discovered to be the best form of spectral transformation for enhancing the contrast between the bright-degraded areas near the points and the darker surrounding areas far from and in between these areas. To comprehend the spatial structure present in spaceborne imagery of two desert sites and three key time periods, semi-variograms were created (mid-late 2000s, around 2015 and 2020). To assess spatio-temporal land-cover patterns, a kriging was used to smooth the brightness index values extracted from 30 m spatial resolution images. To assess the direction and intensity of changes between study periods, a change detection analysis based on kriging prediction maps was performed. These findings were linked to the socioeconomic situation prior to and following the EU economic crisis. The study discovered that degradation occurred in some areas as a result of the region’s agricultural activities being exploited.

En el presente trabajo, y dado el creciente desarrollo de las nuevas tecnologías aplicadas a la teledetección, se llevó a cabo una experiencia educacional innovadora en la asignatura Expresión Gráfica y Cartografía de la ETSI Agronómica de la Universidad de Sevilla, con el propósito de ayudar a los estudiantes a entender, de la mejor manera posible, las diferentes variables y fenómenos a tener en cuenta a la hora de realizar el tratamiento de una imagen teledetectada. En este estudio, un total de 100 alumnos, matriculados en el grupo E de la asignatura, utilizaron el e-Lab de teledetección, de acceso libre, creado por ESRI y perteneciente al U. S. Geological Survey (NASA), donde sus diferentes herramientas basadas en conceptos básicos como la Ley de Wien, así como de otros en los que el conocimiento de los métodos de tratamiento digital de imágenes, son indispensables de cara a la obtención de unos resultados coherentes con el área de estudio definida en cada caso. De acuerdo con los resultados, la mayoría de los estudiantes (86%) mostraron una actitud positiva hacia la experiencia realizada. En lo referente al uso del e-Lab, y en relación con el entendimiento de la teledetección, un 80% de los participantes lograron una muy buena conexión entre conocimientos de diferentes asignaturas a la hora elegir tanto las bandas adecuadas de estudio, como el tipo de filtro a emplear. Los estudiantes piensan que el uso de e-Labs es útil de cara a la conexión entre los mundos académico y profesional.