Browsing by Author "Blazquez, Carola"

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Predicting PM2.5 in Temuco and Padre Las Casas, Chile using Ordinary Kriging
(LACCEI Inc., 2021-07) Cubillos, Juan Carlos; Blazquez, Carola
Ambient air pollution causes serious human health problems. Geostatistical interpolation methods have proven to efficiently estimate exposure to air pollutants. In this study, we employed Ordinary Kriging to predict PM2.5 concentrations due to woodsmoke in the conurbation of Temuco and Padre Las Casas, Chile using mobile measurements conducted during June and July of 2016. Overall, the results suggest that higher PM2.5 concentrations were estimated in Temuco. Spatial differences in high PM2.5 concentrations are observed when examining the PM2.5 estimates by month. The results of this study may help authorities and policymakers to implement environmental actions to reduce air pollution in the studied conurbation.
Spatial and aspatial clustering analysis of PM2.5 concentrations in Temuco, Chile using mobile measurements
(LACCEI Inc., 2020-07) Blazquez, Carola; Montero, Elizabeth
Air pollution due to wood burning produces severe health and environmental problems. Clustering methods are needed to estimate PM2.5 exposures, and identify locations with high PM2.5 concentrations. This study performed a spatial and aspatial clustering analysis of PM2.5 pollutant collected in a mobile campaign in the conurbation of Temuco and Padre Las Casas, Chile. The Getis Ord Gi* statistic was employed to obtain spatial variability of PM2.5 concentrations, and a K-Means clustering method was used to group PM2.5 concentrations with a aspatial perspective. In addition, an integrated spatial and aspatial clustering approach was implemented with the PM2.5 concentration and measurement spatial location. The comparison results suggest that integrating the spatial and aspatial clustering methods yieled high quality partitions when considering spatial information.
Spatial and Temporal Analysis of Fatal and Injury Severity of Road Traffic Accidents in Santiago, Chile
(LACCEI Inc., 2021-07) Mondaca, Matías; Blazquez, Carola
Chile´s capital, Santiago, presented over 91,000 traffic accidents between 2015 and 2018, yielding a total of 47,470 fatalities and severe injury outcomes. This study performed a spatial and temporal analysis of fatal and serious injury accidents to identify statistically significant spatial clusters using spatial statistical approaches at the global and local level. The results revealed that globally both fatality hotspots and spatial clusters of severe injury outcomes with high values tend to cluster over the studied period. Locally, the commune of Puente Alto presents the largest number of clusters with high injury severity index values in Santiago, while the commune of Quinta Normal has the largest clustering intensity of this index. Additionally, the communes of Maipú and Estación Central have the largest number of fatality hotspots among all communes in Santiago, and the highest average intensity of these hotspots are located in Puente Alto. Finally, a comparison between the spatial statistical approaches indicate that 85 locations exist in Santiago, in which both spatial clusters of injury severity with high values and fatality hotspots coincide. The results of this study will aid local authorities, transportation professionals, and planners to improve traffic safety in Santiago.
Spatio-Temporal Analysis of Public Transit Crashes in Viña del Mar and Valparaíso, Chile
(LACCEI Inc., 2020-07) Blazquez, Carola; Salazar, Liliana
The conurbation of Viña del Mar and Valparaíso presented the highest number of public transit crashes in Chile with a total of nearly 350 fatalities and severely injured victims between 2014 and 2018. These crashes are caused mainly due to the imprudence of the driver yielding collisions between two or more moving vehicles, impacts with stationary objects, and falls of passenger from buses. This study performed a spatio-temporal analysis of traffic crashes that involved microbuses and taxi-buses to identify emerging and disappearing hotspots and coldspots during the study period. The results revealed that most crash hotspots due to the imprudence of the driver persisted in time in Viña del Mar, and crash hotspots due to signage disobedience sporadically appeared in Valparaíso. Hotspots of collisions and falls of passengers are types of crashes that emerged solely in Viña del Mar, as well as new, consecutive, and sporadic hotspots of severely injured victims. While morning historical hotspots emerged in Viña del Mar, consecutive, persistent, and sporadic hotspots of crashes appeared in the downtown area in both cities. The results of this study will aid authorities, transportation professionals, and planners make informed decisions about traffic safety.