Spatiotemporal analysis of the atmospheric and surface urban heat islands of the Metropolitan Area of Toluca, Mexico

The growth of urban populations around the globe is undeniable and consolidates in Latin America and the Caribbean, which nowadays is considered the most urbanized region in the world, for almost 80% of its population lives in cities (UN HABITAT 2012). However, many cities expanded without taking into consideration a proper planning that ensured the population’s quality of life. The expansion of the city modified land use and land cover and changed the albedo of the surface as the coverage of green areas decreased, and with this evapotranspiration, wind regime and surface runoff modified; besides, the sources of anthropogenic heat increased (Oke 1987; Lo´pez et al. 1993; Ferna´ndez and Martilli 2012). This impacts the regional conditions of climate, generating a local urban weather. According to Romero et al. (2010) ‘‘Urban climate comes from unnoticed and intentional transformations introduced into local and regional climates, which directly relate with the social construction of spaces and places.’’ All urban climates present common characteristics, being urban heat island its main feature (Oke 1987; Lo´pez et al. 1993; Monta´vez et al. 2000). An urban heat island is defined as an urban area with higher temperature conditions than neighboring non-developable areas (Voogt and Oke 2003). There are two sorts of urban heat islands. The first, atmospheric urban heat island (UHI), represents the differences in air temperature between urban and rural areas. The second, known as surface urban heat island (SUHI), shows termal differences between artificial surfaces (such as asphalt and rooftops) and the natural ones (such as vegetation and cultivations) (Ferna´ndez and Martilli 2012). The most significant when analyzing a heat island features is the shape, intensity and variations in space and time (Lo´pez et al. 1993; Voogt 2008).The dynamic of consolidation of urban areas in Latin America has allowed that almost 80% of the population concentrates in cities; this has produced changes in land covers and modified regional climate, propitiating the appearance of urban heat islands. The Metropolitan Area of Toluca, State of Mexico, Mexico, holds the fifth national place in population size and experiences this process, because of this, the objective is to analyze and compare the spatiotemporal characteristics of the atmospheric urban heat island obtained from data gathered from 12 urban and rural weather stations with the surface urban heat island obtained from the digital processing of four Landsat 8 images. Results show the year-round presence of night-time atmospheric urban heat islands, which reach a peak in autumn (up to 6 _C). Daytime atmospheric urban heat islands occur in summer and autumn with a maximum intensity of 4 _C. For their part, surface urban heat islands occur in spring, summer and autumn and reach maximums of 19 _C in intensity. A strong correlation was found between wetness and Surface temperature (coefficient of determination, 0.8) in spring and winter. Soil wetness directly impacts the formation of weak urban heat islands in dry season, and intense ones in wet season, while the green areas and the winds affect the spatial distribution of the same.Universidad Autónoma del Estado de México - CONACY

Hacia un nuevo paradigma en la elaboración y publicación de cartografía neocientífica: dificultades para la implementación de la Revista Digital Geosciences, especializada en la publicación de cartografía interactiva a través del web

Biblioteca de edición digitalLa cartografía constituye uno de los principales medios de integración y comunicación de información geográfica, siendo una práctica común en muchas disciplinas. El valor de la cartografía ha sido crítico para reportar descubrimientos, así como para ubicar, describir, analizar y medir rasgos o procesos diversos. Los retos que enfrenta la cartografía en Ciencias de la Tierra son reducir los elevados costos de impresión, reducir los tiempos para su actualización y lograr su reconocimiento como publicación científica arbitrada. Como alternativa parcial a esta situación en los últimos años la fusión del Internet y los Sistemas de Información Geográfica con funciones especiales para el Web (Internet Map Server/ Internet Web Server), han hecho posible técnicamente la publicación y la distribución de productos cartográficos interactivos, logrando así reducir costos de producción e incrementar el número de lectores y usuarios de la cartografí