Browsing by Author "Smith, Pamela"

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    Cambio climático y evaluación prospectiva del riesgo por islas de calor urbana en ciudades chilenas
    (Centro de Investigaciones en Geografía Ambiental (CIGA), 2024) Henríquez, Cristián; Smith, Pamela; Guerrero, Nikole; Qüense, Jorge
    Los impactos del cambio climático están afectando a todas las ciudades en distintos órdenes de magnitud, sin embargo, no hay mucha información sobre el nivel de riesgo para las ciudades latinoamericanas. A su vez, el impacto del aumento de temperatura se ve acentuado por el propio efecto urbano, a través del efecto de isla de calor urbano (ICU). En tal sentido, el propósito de este capítulo es estimar el nivel de riesgo asociado al efecto de ICU en un escenario presente y futuro considerando los factores de amenaza, exposición, vulnerabilidad y adaptación en las principales ciudades de Chile. Parte de los resultados forman parte del Atlas de Riesgos Climáticos (ARClim). Para ello se utiliza un enfoque espacial múltiple que combina información climática, urbana, demográfica y social. Se concluye que los principales riesgos se encuentran en las grandes metrópolis, 330 avances en el estudio de islas de calor urbano en américa latina obviamente determinados por la gran exposición y amenaza. Sin embargo, si mejoramos la resiliencia y disminuimos la vulnerabilidad el impacto se puede controlar. Hay ciudades menores que tienen una baja ICU (por ejemplo, Hanga Roa o Coyhaique, con valores bajo 1.5 ºC), pero debido al cambio climático pueden aumentar su ICU sobre los 2.5 ºC, y en promedio el aumento estimado para el conjunto de ciudades sería superior a los 4.2 ºC para 2065. De esta forma, el nivel de riesgo podría aumentar junto con el mayor crecimiento urbano y demográfico, por lo que es urgente implementar medidas y acciones de adaptación urbana.
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    Heat beyond percentiles: exploring preterm birth risks in Santiago, Chile (1991–2019)
    (2026) Blanco, Estela; Conejeros Pavéz, José Daniel Hernan; González-Reyes, Álvaro; Rubilar, Paola; Sarricolea, Pablo; Smith, Pamela
    ObjectiveEvaluate the relationship between extreme heat in the week and month before delivery and risk of preterm birth (< 37 weeks’ gestation) using secondary data from Santiago, Chile.MethodsWe conducted a population-based cohort design using secondary information from birth records (1991–2019) and limited analysis to births in spring/summer months (n = 957,734). Temperature percentiles and the excess heat factor (EHF) were calculated for each of the 33 urban municipalities in Santiago using historical data. We derived 15 distinct heatwave metrics by combining three durations (2, 3, and 4 consecutive days) with five temperature thresholds: temperatures > 30 °C, the 90th, 95th, and 99th percentiles, and EHF. For each municipality, exposure (Yes or No) was assigned for each of these metrics in the week and month prior to delivery. We estimated Cox proportional hazard models adjusted for known confounders.ResultsPreterm birth occurred in 6% of births. There was spatial variability in extreme temperatures for the municipalities. Exposure to most heat wave metrics (≥ 2, ≥ 3, ≥ 4 days > 90th, 95th, and 99th percentile), did not relate to increased risk of preterm birth. Exposure to EHF for ≥ 2, ≥ 3, ≥ 4 days was associated with 1.02 (95% CI 1.00–1.04), 1.03 (95% CI 1.01–1.04), and 1.03 (95% CI 1.02–1.05), respectively. Exposure to ≥ 2, ≥ 3, ≥ 4 days of temperatures > 30 °C were associated with decreased hazards.ConclusionWe found evidence of increased risk of preterm birth, but only when evaluating exposure using EHF, a metric that considers acclimatization. Our results highlight the importance of understanding regional impacts of climate change on child health.
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    Heat vulnerability in a hyper-arid coastal conurbation: downscaled LST and socio-spatial analysis
    (2025) Sarricolea, Pablo; Baltazar, Alexis; Meseguer Ruiz, Oliver; Smith, Pamela; Picone, Natasha; Serrano Notivoli, Roberto; Vidal Paez, Paulina; Fuentealba, Magdalena; Thomas, Felipe
    Heat vulnerability is a critical issue for cities under climate change, especially in socially precarious contexts and extreme climates such as deserts. The Iquique–Alto Hospicio conurbation in northern Chile represents a distinctive case study due to its marked altitudinal contrasts and rapid urban expansion. This research focuses on assessing the Surface Urban Heat Island (SUHI) at its peak expression, during summer nighttime conditions, in order to spatialize heat vulnerability. A multi-scalar workflow was applied, beginning with long-term multitemporal analysis of land surface temperature at moderate resolution (2002–2023) and extending to high-resolution downscaling for five recent years (2019–2023) using bilinear resampling combined with robust regression techniques. A heat vulnerability index was then developed through principal component analysis (four components, ∼74% variance explained), complemented by a spatial cluster analysis based on Anselin’s Local Moran’s I, which delineated statistically significant hot-spots in Iquique’s historic core and in recently formalized social-housing districts on the Alto Hospicio plateau, as well as cold-spots along the affluent coastal seafront. The results confirm the presence of a strong nocturnal summer SUHI, largely coinciding with the most densely populated areas characterized by low-rise housing and limited green space. The local climate zone Compact low-rise and lightweight built forms were identified as the most vulnerable to heat. The study concludes that effective strategies should promote less dense building typologies while incorporating urban infrastructures that act as climate refuges across the conurbation. More broadly, the approach offers a transferable template for climate-resilient planning in data-scarce, arid coastal cities worldwide.
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    Urban climate simulation model to support climate-sensitive planning decision making at local scale
    (2024) Smith, Pamela; Blanco, Estela; Sarricolea, Pablo; Peralta, Orlando; Thomas, Felipe
    Urban planning, through design and land use allocation, affects urban climate dynamics and patterns at different atmospheric layers and spatial scales. Climate sensitive planning and design draws attention to the consideration of climate parameters for decision making. Seeking to contribute to the above, this research set out to identify the effect of urban design features (e.g., vegetation cover and construction density) on air temperature behavior. We conducted a case study, selected the Renca municipality located north-west Santiago, Chile, which represents a Mediterranean urban area affected by an intense daytime and nighttime urban heat island (UHI). We developed simple linear regression models to estimate air temperature per block in four different present and future scenarios: summer and winter and for day (16:00) and night (23:00). The urban-environmental variables were evaluated with the air temperature data series, measured in 21 points in the commune which were representative of urban and natural local climatic zones (LCZ). The results were evaluated and validated. We observed that variables such as vegetation, surface temperature or relative humidity are important explanatory factors for air temperature at the block scale in Renca across all four models. Models represent a tool that allows the evaluation of different design and urban planning alternatives at the scale of a city block, providing useful information for climate-sensitive decision-making.
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    Variación en la intensidad de la isla de calor urbana por efecto del cambio climático en ciudades chilenas
    (2021) Henríquez, Cristián; Smith, Pamela; Contreras San Martín, Paulina; Qüense, Jorge
    La Isla de Calor Urbano (ICU) es la principal característica del clima urbano y se define como la diferencia entre la temperatura urbana y la temperatura rural. Su existencia se explica por el diseño y materiales de construcción de la ciudad, superficies impermeables y no evapotranspirantes, y sus efectos son de diversa índole. La magnitud e intensidad de la ICU depende, a su vez, del tamaño de la ciudad y por ello, del volumen de población concentrada espacialmente. El objetivo de esta investigación es proponer una metodología que permita estimar la intensidad máxima de la ICU presente y futura mediante una aproximación de múltiples modelos (climáticos y de usos de suelo) y considerando los efectos del cambio climático. Los resultados demuestran que la ICU promedio de las principales ciudades chilenas analizadas es consistente con valores de estudios internacionales, destacando el caso del Gran Santiago que llegaría a tener una ICU mayor 10 ºC.