Urban Intensities. The Urbanization of the Iberian Mediterranean Coast in the Light of Nighttime Satellite Images of the Earth

Abstract

The contribution shares the approach of critical urban studies that have conceptualized urbanization more as a process than as a sum of spatial forms. Thus, the contribution studies the urbanization process not only from the point of view of the physical occupation of land but also considers changes in the intensity of the uses of space. To fulfill this aim, the new sources of nocturnal satellite images are particularly useful. These allow us to observe the intensity of urban uses both in terms of their distribution over space and their recurrence over time. The research focuses on the Iberian Mediterranean coast and permits the verification of the intensity of the urban uses of the space for the whole of this area and their seasonal variations throughout the year. The source of the study are the nighttime satellite images of the Earth for the 2012–2017 period from the NASA SNPP satellite equipped with the VIIRS-DNB instrument. By establishing a threshold of urban light the research shows that those districts with the greatest extensions of urban light do not necessarily correspond with the most densely populated areas. Similarly the absence of urban light does not necessarily indicate the absence of urban uses. Finally, the variations of intensity of light prove to be a good indicator of seasonal variations of activity in tourist areas.

Megaciudad Buenos Aires: Cartografía de su última expansión y conurbación mediante el procesamiento digital de imágenes satelitales nocturnas

“…En esta etapa de la investigación se tuvieron en cuenta como referencia los trabajos desarrollados por el Grupo de investigación sobre Energía, Territorio y Sociedad de la Universitat Autónoma de Barcelona (Nel.lo et al, 2016;Checa et al, 2017;Checa & Nel.lo, 2018).…”

“…Como el objetivo de la investigación gira en torno al conocimiento de la extensión de la superficie urbana a partir de la superficie iluminada y, como no todos los píxeles con valores mayores que cero corresponden a las áreas de cobertura urbana, se estimó un valor mínimo (intensidad lumínica) de referencia ligado a diversas construcciones materiales humanas (Checa & Nel.lo, 2018) 4 que en el presente trabajo se denominan de manera amplia infraestructura gris. Para concretar este paso, era necesario contar con una capa de cobertura urbana que permitiera realizar una superposicion sobre las imágenes nocturnas y poder aproximar un valor mínimo como umbral de luminosidad urbana.…”

“…Las imágenes resultantes de los procesos anteriores permitieron derivar los principales resultados de la investigación. Primero, se vectorizaron para luego calcular la 4 Esto no quiere decir, que los usos urbanos no se puedan extender en aquellas áreas con niveles de luz por debajo del valor de referencia establecido, como aclara Checa & Nel.lo (2018) el concepto de luz urbana debe entenderse en terminos de intensidad más que de exclusión.…”

Using Volunteered Geographic Information and Nighttime Light Remote Sensing Data to Identify Tourism Areas of Interest

“…Jurgens et al, experimentally illustrated that there are not so many false location information [64]. Furthermore, recent studies have indicated that NTL data is highly correlated with urban infrastructures and socio-economic activities such as tourism [65,66]. Therefore, regions with either enough BF (or enough NTL intensity) are assumed to ensure minimum infrastructure necessary for tourism activities.…”

“…It has been extensively used in understanding the various anthropogenic phenomenon. Also, correlating the NTL brightness with other variables such as buildings and settlement areas, bridges and communication routes, and demographic and socio-economic activities have generated good results which have proved useful for decision making [65,66,82,83].…”