CEDEUS

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A bumpy ride: structural inequalities, quality standards, and institutional limitations affecting cycling infrastructure
(Elsevier Ltd, 2022) Tiznado-Aitken, Ignacio; Mora Vega, Rodrigo; Oyarzun, Gabriel; Vergara, Jaime; Vecchio, Giovanni; CEDEUS (Chile)
Structural socio-economic and institutional limitations can affect the implementation of cycling infrastructure. More stringent cycling infrastructure standards aiming to solve deficiencies might exacerbate disparities, especially in poor districts with fragmentary governance. Using an audit and quantitative and spatial analysis of cycleways, this paper examines to what extent structural inequalities and governance issues affect the availability and quality of cycling infrastructure, considering new indicative and normative standards aiming at improving cycling infrastructure in Santiago, Chile. Our results show that the distribution of cycleways is unequal and only partially complies with national quality standards. All districts in the city have both high and low standard bicycle lanes, but since district finances have huge differences, this can lead to inequalities in cycle coverage and districts' capabilities to address current standard problems. This raises relevant challenges regarding governance and how to ensure an equitable distribution of cycling infrastructure in Global South cities.
A temporal analysis of the consequences of the drought regime on the water footprint of agriculture in the Guadalupe Valley, Mexico
(2024) Novoa, Vanessa; Rojas Quezada, Carolina Alejandra; Rojas, Octavio; Ahumada-Rudolph, Ramón; Moreno-Santoyo, Rebeca; CEDEUS (Chile)
Changes in water availability have a substantial impact on the sustainability and maintenance of agriculture, with water footprint (WF) being a robust methodology to assess these transformations. The Guadalupe Valley is one of the places with the highest agricultural production in Mexico. Despite its semi-arid climatic conditions, it provides high-quality crops that are well-positioned in the world. The historical trend of rainfall and temperatures between 1987 and 2017 was analyzed to identify climatic patterns in the territory. Through the calculations of the water footprint of Grapevine and Olive crops, the sensitivity of the crops to recurrent water deficit and their adaptation in their yields to drought episodes was identified. The reduction in precipitation and occurrence of extreme temperatures have contributed significantly towards augmenting crop evapotranspiration and, consequently, intensifying crop irrigation demands. As a result, there has been an apparent increase in the consumption of WFagricultural since 2007. Thus, the period of highest WFagricultural consumption was 2014 (Extremely dry), as opposed to 2011 (Very wet). In particular, the lowest WFgreen consumptions were observed in extremely dry years, that is, > 20% of the WFagricultural intensifying drought events. Therefore, these periods were compensated with higher uses of WFblue and WFgray, which are inversely correlated with precipitation, where vine crops consume 73% more WFagricultural compared to olive plantations, showing greater interannual variability. These results contribute to analyzing the temporal evolution of water consumption for agriculture, providing a basis for rational water use strategies.
Bus drivers and their interactions with cyclists: An analysis of minor conflicts
(Elsevier Ltd, 2024) Mora, Rodrigo; Waintrub Santibanez, Natan; Figueroa-Martinez, Christian; CEDEUS (Chile)
Driving a bus in a city is a challenging task as it demands paying attention to changing conditions (e.g., weather, congestion) while interacting with passengers and other road users who sometimes display unpredictable behaviours. Cyclists play an important role in these interactions. This paper investigates how cyclists are perceived by bus drivers and how conflicts arising from their daily interactions shape the attitudes of bus drivers. A total of 639 bus drivers (4% of the workforce, 91% males) working in Santiago de Chile responded an online survey. The survey asked drivers about their perception of other transport modes, their experience with traffic collisions and the conflicts they have had with cyclists. Later, logistic regression models were estimated, using “coexistence with cyclists” as the dependent variable. The findings show that younger and older drivers have a better perception of cyclists compared to middle-aged ones. Negative experiences with cyclists worsen the perception of co-existence with cyclists; meanwhile, previous cycling experience was unrelated to drivers’ perceptions. The results also suggest that existing norms are perceived as ineffective. Finally, gender was not statistically significant in shaping bus drivers’ perception of cyclists, yet this topic requires further attention as the composition of the public transport labour force is changing.
Children and young people’s unaccompanied mobility: the role of the built and social environments in an unequal Latin American Metropolis
(2024) Waintrub Santibáñez, Natan; Jones, Peter; Tyler, Nick; CEDEUS (Chile)
Unaccompanied trips are highly beneficial for children, yet their practice is difficult in unequal Latin American metropoles. This article investigates how the built and social environments influence children and young people’s trips in Santiago de Chile. It does so by reporting the findings of a stated preference questionnaire in which children and young people were invited to choose the preferred environment to walk unaccompanied in between pairs of images illustrating different social and physical attributes. The findings suggest that Santiago’s inequalities are mirrored in the environments through which children and young people prefer to walk unaccompanied. Attributes that enhance the streetscape (e.g., well-kept footpaths, grass), provide recreation and natural surveillance positively affect children’s willingness to make unaccompanied trips in wealthy areas. By contrast, those attributes are less significant for children and young people from other parts of the city, where other features have a greater impact (e.g., strangers drinking alcohol, off-licences, vehicles parked on the footpath). Furthermore, young girls are greatly discouraged from travelling unaccompanied in most circumstances, in both wealthy and not-wealthy areas. Public policies should prioritise non-wealthy neighbourhoods, improve the built environment, and strengthen local communities and local familiarity to create safer spaces that encourage unaccompanied trips.
Development and validation of a numerical heat transfer model for PCM glazing: Integration to EnergyPlus for office building energy performance applications
(Elsevier Ltd, 2024) Uribe, Daniel; Vera, Sergio; Perino, Marco; CEDEUS (Chile)
© 2024 Elsevier LtdGlazing filled with Phase Change Materials (PCMs) or PCM glazing arises as a strategy to improve the office buildings' energy performance by providing thermal inertia to glazed façades. PCM glazing can reduce office buildings' cooling energy consumption in warm climates. Literature shows a good understanding of PCM glazing thermophysical properties. However, nowadays, it is unfeasible to estimate the energy consumption of offices with PCM glazing based on annual energy simulations. Therefore, this paper aims to integrate a novel, developed, and validated PCM glazing heat transfer model for building energy performance applications into EnergyPlus. In order to do this, a numerical heat transfer model of a double-clear glazed filled with PCM based on literature is developed. This model is validated experimentally and integrated into EnergyPlus, a state-of-the-art building energy simulation tool. Annual simulations are carried out for an office room with different WWR, façade orientations, and PCMs in four climate conditions to show the model's capability to estimate the energy consumption and cooling peak load reductions. The results show that double-clear glazing filled with PCM can reduce the energy consumption of an office building up to 9.1 % and reduce the cooling peak loads up to 10.5 % compared to the same office building with a triple-clear glazing filled with argon. The best results were observed in warm climates with significant diurnal temperature variations.
Energy and structural optimization of mid-rise light-frame timber buildings for different climates and seismic zones in Chile
(2024) Wenzel Schwarzenberg, Alexander; Vera Araya, Sergio Eduardo; Guindos Bretones, Pablo; CEDEUS (Chile)
Location determines not only the climatic condition but also the structural loads that the structure must withstand. Given the broad variety of climatic and seismic requirements of Chile, the design of lightweight timber buildings considering both energy and seismic design parameters and boundary conditions becomes a difficult task. The main objective of this research is to analyze and quantify the effect of climates, seismic loads, lateral anchorage, and story number on the optimal energy design solutions, including the seismic behavior in a light-frame timber building. Furthermore, the optimal design was parametrically analyzed considering five Chilean cities that consider different climates, seismic zone, number of stories, and lateral anchorage systems to prevent rocking (overturning) due to lateral seismic forces. The optimal wall insulation thickness, stud spacing, and thermal mass exhibited significant variations depending on the buildings' number of stories, lateral anchorage system, climate, and seismic zone. Therefore, the results of this investigation reinforce the necessity of integrating energy and seismic designs for light-frame timber buildings. The optimal designs obtained in this investigation showed considerable variations depending on the combination of climatic and seismic loads as well as the number of stories and anchoring systems. The article's main contributions are the evidence of the structural and energy design interconnection of light-frame timber buildings and how design variables, such as stud spacing, floor concrete thickness layer, and wall insulation thickness, are related and change according to the different climates, seismic loads, lateral anchorage, and story number.
Fare evasion on public transport: Who, when, where and how?
(2022) Cantillo Torregrosa, Luis Ángel; Raveau Feliú, Sebastián; Muñoz Abogabir, Juan Carlos; CEDEUS (Chile)
Transantiago, the public transport system of Santiago, Chile, has one of the highest fare evasion rates registered worldwide. The official statistics for late 2019 indicated that the evasion rate in bus legs was 26.6% while in metro it was almost 0%. This is a relevant issue due to the impacts of fare evasion on finances and quality of service, as budget constraints put pressure on the transit system. Analysing and understanding fare evasion should be the starting point for proposing solutions that could reduce it. Therefore, in this research we seek to answer the question of who are the evaders, when and where evasion happens and how is the fare evaded on public transport. To answer these questions, extensive data was gathered onboard buses of Transantiago for five full days (19 h a day) of operation, including weekdays and weekend. A total of 10,559 individual records were collected. The information considers age and gender of travellers, and fare evasion was measured in zones of Santiago that are characterised by very different economic conditions. Records also differ in terms of bus occupancy, presence of turnstiles in the buses, and types of stops (with and without off-board payment). Based on the collected information, a Binomial Logit model was calibrated to understand and explain fare evasion, quantifying the effect of different types of explanatory variables. Results show that fare evasion is higher for young men, evening and night periods, low-income neighbourhoods, crowded buses without turnstiles, bus stops without off-board payment and weak accessibility to metro stations and fare vending machines. The model does not only allows the identification of these trends, but is also able to quantify them. Based on the results, potential proposed solutions to tackle evasion are discussed.
Greening at multiple scales promote biodiverse cities: A multi-scale assessment of drivers of Neotropical birds
(Elsevier GmbH, 2021) Villaseñor, Nélida R.; Truffello, Ricardo; Reyes Paecke, Sonia; CEDEUS (Chile)
© 2021 Elsevier GmbHBiodiversity-sensitive cities can contribute to reconnect humans with nature and halt global biodiversity loss. Achieving biodiversity-sensitive cities is challenging, especially in regions threatened by growing urbanization. To inform urban management and planning in a global biodiversity hotspot, we conducted a multi-scale assessment of drivers of Neotropical birds in the capital city of Santiago de Chile. We investigate the influence of local and landscape variables on native bird species richness and abundance. We surveyed birds and vegetation in 449 sampling points distributed across the city. Native bird species richness was greater in areas with greater shrub and woody vegetation cover at the local scale. Native bird species richness was also greater with high vegetation density in the surrounding landscape and near to an urban boundary. Native birds were abundant in areas with large woody vegetation cover at both local and landscape scales, high vegetation density in the surrounding landscape, near to an urban park and near to an urban boundary. Additive effects of vegetation at different spatial scales suggest that combining local and landscape management, planning and design will be best to preserve native birds in a large city. Although native birds are species rich and abundant near the urban fringe and decrease towards the interior of the city, local-scale management of habitat encouraging shrub and tree planting and landscape-scale actions such as targeting high levels of vegetation (including woody cover) and providing a well-distributed network of urban parks will help sustain native birds across the city. Greening actions at local and landscape-scale will contribute to achieving biodiversity-sensitive cities, providing benefits for people and nature.
Impact of Land Use Diversity on Daytime Social Segregation Patterns in Santiago de Chile
(MDPI, 2022) Fuentes Arce, Luis; Truffello, Ricardo; Flores, Mónica; CEDEUS (Chile)
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.Latin American cities are known for their high levels of marginality, segregation and inequality. As such, these issues have been the subject of substantial discussions in academia, with the predominant approach being the study of residential segregation, or what we call “nighttime segregation”. Another dimension of urban sociability, related to labor, is what we call “daytime segregation”, which has been far less studied. This article makes an original methodological contribution to the measurement of non-residential or daytime segregation based on data from mobility surveys. It seeks to explain this segregation measurement according to the diversity and distribution of land uses, as well as other characteristics of the built stock, such as land price and built-up density. We measured daytime social mix in urban spaces, and we show how it highly relates to land use diversity in a Latin American megacity, such as Santiago, Chile. We found that land use diversity plays a key role in enhancing the daytime social diversity of urban spaces, contributing to generate a more heterogeneous city and social gatherings during working days. This research is not only a contribution to the understanding of sociability patterns in cities but is also a contribution to public policy and the work of urban planners, as it informs the development of more diverse and integrated cities, which is a key tool for strengthening democracy, the exchange of ideas, the economy and social welfare.
Local and NON-LOCAL source apportionment of black carbon and combustion generated PM2.5
(Elsevier Ltd, 2024) Rodríguez Rangel, Jessika Carolina; Villalobos, Ana María; Castro-Molinare J.; Jorquera González, Héctor Iván Joaquin; CEDEUS (Chile)
Current methods for measuring black carbon aerosol (BC) by optical methods apportion BC to fossil fuel and wood combustion. However, these results are aggregated: local and non-local combustion sources are lumped together. The spatial apportioning of carbonaceous aerosol sources is challenging in remote or suburban areas because non-local sources may be significant. Air quality modeling would require highly accurate emission inventories and unbiased dispersion models to quantify such apportionment. We propose FUSTA (FUzzy SpatioTemporal Apportionment) methodology for analyzing aethalometer results for equivalent black carbon coming from fossil fuel (eBCff) and wood combustion (eBCwb). We applied this methodology to ambient measurements at three suburban sites around Santiago, Chile, in the winter season 2021. FUSTA results showed that local sources contributed ∼80% to eBCff and eBCwb in all sites. By using PM2.5 – eBCff and PM2.5 – eBCwb scatterplots for each fuzzy cluster (or source) found by FUSTA, the estimated lower edge lines showed distinctive slopes in each measurement site. These slopes were larger for non-local sources (aged aerosols) than for local ones (fresh emissions) and were used to apportion combustion PM2.5 in each site. In sites Colina, Melipilla and San Jose de Maipo, fossil fuel combustion contributions to PM2.5 were 26 % (15.9 μg m−3), 22 % (9.9 μg m−3), and 22 % (7.8 μg m−3), respectively. Wood burning contributions to PM2.5 were 22 % (13.4 μg m−3), 19 % (8.9 μg m−3) and 22% (7.3 μg m−3), respectively. This methodology generates a joint source apportionment of eBC and PM2.5, which is consistent with available chemical speciation data for PM2.5 in Santiago.
Spatiotemporal vegetation dynamics in a highly urbanized Chilean coastal wetland: Insights on long-term natural and anthropogenic influences
(2024) Munizaga, Juan; Rojas, Octavio; Lagos, Bernardo; Rojas Quezada, Carolina Alejandra; Yepez, Santiago; Hernández, Esteban; Ureta, Fernando; de la Barrera, Francisco; Jato-Espino, Daniel; CEDEUS (Chile)
This study analyzes the spatiotemporal dynamics of the vegetation of a highly urbanized coastal wetland in the 2000–2020 period, considering natural disturbances and anthropogenic stressors. The wetland system was stratified into four domains: Coastal, Intertidal, Freshwater, and Urban, differentiated by their geomorphological, topographical, and water salinity characteristics, which were validated by ground vegetation sampling. In these domains, spectral indicators of vegetation were used on 884 Landsat images in the Google Earth Engine to determine vegetation types, trends, and phenology. The start of the growing season coincides with the beginning of the Austral winter, exhibiting seasonal behavior, which was interrupted by abrupt natural disturbances such as floods and tsunamis. In addition, a progressive trend associated with the replacement of native species by exotic species was reported in areas with significant anthropogenic stressors (e.g., highways, city edges, and grazing areas), with 45 % presenting an increase in the normalized difference vegetation index. Areas far from anthropogenic stressors maintained their behavior, which is explained by natural factors such as precipitation, temperature, and evapotranspiration. The proposed method strengthens our understanding of the interrelationship between factors that modify the behavior of vegetation in coastal wetlands pressured by anthropogenic stressors and contributes to their management and protection.
Synthetic greywater treatment using a scalable granular activated carbon bioelectrochemical reactor
(Elsevier, 2024) Gallardo Bustos, Carlos; Tapia Flores, Natalia F.; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
Greywater reuse has emerged as a promising solution for addressing water shortages. However, greywater needs treatment before reuse to meet the required water quality standards. Conventional wastewater treatment technologies are unsuitable for recreating highly decentralized domestic greywater. This study evaluated bioelectrochemical reactors (BERs) with granular activated carbon (GAC) as a sustainable alternative for developing decentralized and low-cost biological treatment systems. BERs using GAC as the anode material and conventional GAC biofilters (BFs) for synthetic greywater treatment were operated in batch mode for 110 days in two stages: (i) with polarized anodes at −150 mV vs. Ag/AgCl and (ii) as a microbial fuel cell with an external resistance of 1 kΩ. Anode polarization produced an electrosorption effect, increasing the ion removal of the BERs. Power production during the operation and cyclic voltammetry tests of the extracted granules revealed electrochemically active biofilm development on the BERs. Although low power density (0.193 ± 0.052 µW m−3) was observed in BERs, they showed a similar performance in sCOD removal (BER = 91.6–89.6 %; BF = 96.2–93.2 %) and turbidity removal (BER = 81–82 %; BF = 30–62 %) to BFs that used 50 % aeration. Additionally, scanning electron microscopy of sampled granules showed higher biomass formation in BER granules than in BF granules, suggesting a higher contribution of sessile (vs. planktonic) cells to the treatment. Thus, the results highlight the synergistic removal effect of the GAC-based BER. The scalable design presented in this study represents a proof-of-concept for developing BERs to use in decentralized greywater treatment systems.
Uncovering gender-based violence and harassment in public transport: Lessons for spatial and transport justice
(Elsevier Ltd, 2024) Tiznado Aitken, Ignacio Andrés; Guerrero Barbosa, Thomas Edison; Sagaris, Lake; CEDEUS (Chile)
When suitably organized, public transport plays an important role in social inclusion and equity by providing crucial access to social, political, and economic opportunities. Notwithstanding, a growing body of evidence points to gender-based harassment and violence associated with public transport journeys as significant barriers to women's travel. This raises important issues regarding spatial and transport justice. Using a survey in Santiago, Chile, this study explores gender-based violence and harassment experienced while accessing, egressing, and using public transport. We use zero-inflated and logistic regression models to explore individual, behavioral and spatial factors associated with gender violence, particularly sexual harassment, defined as unwanted touching, filming or photography, stalking or masturbation, and rape. We examine these factors differentiating by trip segment (access to and egress from the system versus in-vehicle experience) and public transport mode (bus and Metro). Our results show that 17.5% experienced four or more harassment situations. Public masturbation or rape primarily occurred on the journey to and from public transport (8.6%) and on board a bus (7.4%). Our models indicate a spatial component of harassment which intersects with behavioral and individual factors as trip frequency, trip purpose, gender, age, and income, reducing public transit's ability to serve women, particularly those in low-income living in more peripheral areas. This article contributes to knowledge regarding how these factors interact in a major city in the Global South, which has been under-explored to date. Our findings join other studies challenging theories of spatial and transport justice, which to date pay little attention to violence in general and gender-based violence in particular. We make suggestions for reinforcing theory in order to develop stronger solutions to ensure transport systems improve equity rather than locking in current discrimination and exclusions.
Urban growth and waste services: exploring scenarios in an inter-municipal cooperative framework in Sogamoso city, Colombia
(2024) Pulido Ricaurte, Fredy Leandro; Henríquez, Cristián; CEDEUS (Chile)
The spatial dimensions of city expansion in Latin America reveal the emergence of new urban agglomeration and metropolization phenomena. In this context, the goal is to implement a predictive model of land use change between 1976 and 2047 in the city of Sogamoso and neighboring municipalities in Colombia and to apply its results to a proposal for inter-municipal cooperation in the collection of solid household waste. The methodology used is based on a spatially explicit models using the CA_Markov model in Idrisi Selva software that incorporates Markov chains, multi-criteria evaluation, and cellular automata to identify future areas of urban expansion. The model forecasts urban growth from 2,420 ha in 2021 to 5,278 ha in 2047. The spatial distribution of the new urban areas implies collection routes that are ever farther away from the main urban centers. There is thus a vital need for new regional planning practices (such as inter-municipal cooperation).
Wallmapu-Araucanía in flames! An historical political ecology of fire in the domination of southern Chile
(2024) Escalona Ulloa, Miguel; Barton, Jonathan R.; CEDEUS (Chile)
The conflict over Wallmapu-Araucanía in southern Chile, between the Spanish conquistadores, the Chilean state and the Mapuche peoples, dates from the 16th century, with a key moment being the forced integration of Mapuche land into the Chilean state in the late nineteenth century. This paper discusses this long period of conflict in three moments: conquest, occupation and liberation, and it focuses on the use of fire as a politico-symbolic and techno-productive tool. A ‘landscapes of power framework’ is used for this historical political ecology analysis, based on texts from the nineteenth century to the present. The conclusions point to the historical importance of the use of fire as a tool not only for physical changes in the landscape, but principally as a tool of political symbolism that relates to a history of conflict of terror and displacement, used by the forces of occupation and resistance.
Women’s mobilities and perceived safety: urban form matters. Evidence from three peripheral districts in the city of Bogotá
(Routledge, 2023) Pucci, Paola; Vecchio, Giovanni; Gallego Vega, Erika Andrea; CEDEUS (Chile)
The paper aims at investigating the interplay of urban form and women’s mobilities in three peripheral districts in the city of Bogotá. Integrating a morpho-functional analysis of the built environment with an ethnographic analysis focused on the walking practices of a sample of women, the paper highlights the main gendered spatial experiences and how the perceived safety acts as a mediator between built environment attributes and walking behaviours. The conclusion introduces two challenges: first, the need for new interpretative lenses, different from those of a man-centred perspective and able to interpret the women’s territoriality–considered as the spaces produced through their mobility practices; second, the possibility to use women’s mobilities experiences and their tactics of adaptation as a tool for more effective urban and mobility policies.

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