Spatio-temporal variation of the urban heat island in Santiago, Chile during summers 2005–2017

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Urban heat islands (UHIs) can present significant risks to human health. Santiago, Chile has around 7 million residents, concentrated in an average density of 480 people/km2. During the last few summer seasons, the highest extreme maximum temperatures in over 100 years have been recorded. Given the projections in temperature increase for this metropolitan region over the next 50 years, the Santiago UHI could have an important impact on the health and stress of the general population. We studied the presence and spatial variability of UHIs in Santiago during the summer seasons from 2005 to 2017 using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery and data from nine meteorological stations. Simple regression models, geographic weighted regression (GWR) models and geostatistical interpolations were used to find nocturnal thermal differences in UHIs of up to 9◦ C, as well as increases in the magnitude and extension of the daytime heat island from summer 2014 to 2017. Understanding the behavior of the UHI of Santiago, Chile, is important for urban planners and local decision makers. Additionally, understanding the spatial pattern of the UHI could improve knowledge about how urban areas experience and could mitigate climate change

Landscape Fragmentation at Arauco Province in the Chilean Forestry Model Context (1976–2016)

Land Cover–Land Use Changes (LULCC) and landscape fragmentation have been a common research topic for Geographic Information Systems (GIS) scientists since the middle of the 20th century; particularly, they have helped to make accessible the spatial characteristics of land management through time. We researched LULCC and landscape fragmentation in Arauco Province in Chile using satellite image analysis (1976–2016) and FRAGSTAT software. This area is in a constant struggle for land use between agroindustry, urban sprawl, and the expansion of exotic plantations (pine-eucalyptus) subsidized by Chilean government. The main results are: (1) we obtained the surface percentages for each land cover , (2) net changes for each cover by adding and losing surface (ha), (3) the transition map that enlightens the surface transformations of LULCC by its four processes substitution, abandonment, habilitation, regeneration and degradation, (4) the native forest loss in the first half of the period (1976–2001) was 1.85%/year, meanwhile for the second half (2001–2016) it was 6.5%/year, (5) landscape fragmentation processes occurred in patches and deforestation is its main driver, (6) aggregation changed the landscape since fragmentation and deforestation processes started the substitution of native forest, and (7) the habilitation of agricultural lands and degradation of wooded masses with exotic species increased their aggregation to 90%