East West Street Research Articles

Measuring solar radiation and spatio-temporal distribution in different street network direction through solar trajectories and street view images

Under the dual pressures of rapid urbanization and global warming, the management of solar radiation has become an urgent issue to address. In this context, the potential regulatory role of urban street networks on solar radiation has garnered widespread attention. However, existing research lacks an understanding of the impact of street direction. By utilising street view data and solar trajectory simulation technology, it becomes possible to facilitate the revelation of spatiotemporal differences in solar radiation across streets with different direction. The results show that solar radiation is generally lower on north–south streets than on east–west streets. In terms of spatial differences, the average solar radiation in the fifth ring of Beijing is 25.38% higher than that in the second ring. Temporally, the average solar radiation in August, the highest month, is 15.98% greater than in October, the lowest month. Additionally, solar radiation on east–west street direction shows more intense variations in summer. A periodic variation in solar radiation was also discovered in relation to street angles, with different frequencies and amplitudes at 30° and 180°. This study is the first to focus on the directional attributes of roads at an urban scale. By utilising 100,000 street view images, it calculates and analyses the spatiotemporal distribution of solar radiation in Beijing during summer across different direction. The findings provide new insights into the relationship between the distribution of solar radiation and the morphology of urban roads.

조선시대 정의현 읍치의 조성 과정과 공간구조

In the Joseon Dynasty, the center of Jeongui-hyeon was first established in Goseong-ri, Seongsan-eup, and then moved to the current Seongeup-ri in 1423. The construction of the citadel was carried out in five days despite the cold winter. It has a three-door structure: the west gate, the east gate, and the south gate, and has a T-shaped street network. The government office buildings were mainly located in the north, and a private houses were located in the south.,The factors that determine the location of town in Jeongui-hyeon include location factors, water factors, military factors, and geomantic factors. In addition, despite being a middle-mountainous region, the water was relatively abundant. In addition, since it is located inland, it is less invasive than the coast, and it is located in a propitious site where Hallasan Mountain's veins continue even from geomantic principles. Since Jeongui-hyeon has a relatively low status as a town, there are no various government buildings like Jejumok, and only the government buildings, for example, gaeksa, dongheon, hyangcheong, jilcheong, and military offices were built. There seems to have been little change in the location of gaeksa and donghan, and the location of other government buildings seems to have continued to fluctuate. Overall, the layout of the building was located on the north side of the east-west street network, and in the center was gaeksa symbolizing the kingship.

The Influence of Street Morphology on Thermal Environment Based on ENVI-met Simulation: A Case Study of Hangzhou Core Area, China

The urban thermal environment has become a challenging issue. Streets, as an essential public space in cities, can be laid out in such a way to effectively alleviate a problematic urban thermal environment. In this study, we calculated the layout characteristics of various types of streets in the study area based on network big data combined with field research. We used ENVI-met thermal environment numerical simulation technology to simulate the thermal environment, with a multiple linear regression model to explore the internal relationship between the street-level thermal environment of each land use type and its layout factors. The results indicate that streets in the study area are primarily oriented north–south and east–west, with distinct layout differences among various street types. Additionally, the daily variation trend of thermal comfort PMV of all street types is similar, though north–south streets show a larger daily variation than east–west streets. Lastly, the optimal thermal environment layout differs for each type of street; the relationship between street form and thermal comfort PMV also varies across different street types. This study provides scientific evidence to better understand the relationship between a street’s layout and its thermal environment, offering a theoretical basis for street layout planning aimed at mitigating the urban thermal environment.

Developing a three-dimensional urban surface model for spatiotemporal analysis of thermal comfort with respect to street direction

Understanding the urban heat problem, which is intensifying owing to urbanization and climate change, has become a great challenge. Evaluating the thermal environment of urban spaces and predicting changes based on urban planning are essential for developing optimal urban cooling plans. This study addresses the pressing challenge of urban heat by developing a three-dimensional urban surface model (3D-USM) and conducting spatiotemporal thermal comfort simulations, providing valuable insights for the development of effective urban cooling strategies in the face of urbanization and climate change. Mean radiant temperature (MRT), the key element of thermal comfort of humans by reflecting complex urban environments was simulated in east-west streets which are vulnerable to heat, and results demonstrate that a small change of street angle has a significant effect on pedestrian thermal comfort. Specifically, at 0900 LST, the southern sidewalk of the street rotated by 12.5° was more vulnerable than the northern sidewalk. This resulted in a shift in the optimal location of trees that provide effective cooling, highlighting the importance of considering street orientation in the placement of urban greenery. This suggests that spatiotemporal thermal comfort simulations considering urban form in detail are necessary to efficiently cool the city. The proposed 3D-USM, capable of accurately and efficiently simulating the thermal environment and MRT thermal comfort in complex urban environments using simple input data, holds great potential for guiding the development of efficient cooling strategies to foster sustainable cities.

Study on Strategies to Implement Adaptation Measures for Extreme High Temperatures into the Street Canyon

The purpose of this study is to evaluate the potential for using the spaces integrating the roads and sidewalks in the street canyon as human-centered spaces, and to investigate more appropriate measures to improve the thermal environment for pedestrians and visitors in these spaces. Based on the spatial distribution of SET* throughout the day, as possible human-centered street space uses, north–south streets with restricted widths and south sidewalks on east–west streets are candidates. Spatiotemporal distributions of SET* were calculated when water was sprinkled on the road surface in the street canyon and when water surface, sunshade, and trees were introduced in the street canyon. Assuming people walk or stay on the water surface, the MRT decreases, causing SET* to be below 31.5 °C at any time, so if a continuous supply of water is guaranteed and people can approach the water surface, the water surface can be expected to have a significant impact anywhere at any time. On the east–west street, shading by sunshades and trees occurs along the lanes at any time, allowing pedestrians moving through the lanes to pass through the shaded areas on a periodic cycle. On north–south street, the time required for the countermeasures is limited to around noon, so the measure is effective even if the shade does not occur in the target lanes only around noon.

The Synergistic Effect of Urban Canyon Geometries and Greenery on Outdoor Thermal Comfort in Humid Subtropical Climates

Understanding the synergistic effect of multiple parameters is helpful to urban planners trying to design sustainable cities through a holistic approach. The objective of this research was to investigate how the street aspect ratio (HW), street orientation (AO), and greenery parameters, such as leaf area density (LAD) and aspect ratio of trees (ART), could affect the microclimate and outdoor thermal comfort of street canyons in a central business district under the local climate conditions of Chongqing city. To achieve this goal, a series of single- and multi-parameter simulations which followed an orthogonal design of experiments (ODOE) were conducted. The physiological equivalent temperature (PET) was adopted to assess the results of microclimate simulations for different urban models. The main findings are as follows: 1) The aspect ratio and orientation of urban canyons and ART play significant roles in influencing microclimate variables at the pedestrian level. 2) There is an inverse relationship between the street aspect ratio and Tmrt, and likewise for ART; the highest wind velocity was obtained when the aspect ratio of canyons was 2 and 3, which consequently developed the channeling phenomenon (when the domain wind is prevailing with street direction). 3) The East–West streets and canyons with an HW = 0.5 incur the warmest thermal conditions and longest extreme discomfort durations. 4) Results for the PET and meteorological parameters exhibit less significant variation obtained from different values of LAD than those observed in the other three parameters.

거주민의 동네 영역 인지와 가로 특성 간의 관계 : 충남 아산시 온양동을 중심으로

Purpose: The size and concept of community has changed for decades of urbanization and the rapid change of technology. The concept of neighborhood has also been vague as a result, and the neighborhood territory should be redefined reflecting the time and area of the society. This study was conducted to investigate the physical and social elements that affect the concept of neighborhood. Method: A sample of the residents’ area cognition map of neighborhood territory was surveyed in Onyang, A-san in South Korea. The land use and environments of the area as well as the following physical conditions were investigated; surrounding conditions and levels of the selected three east-west streets divided into six areas were investigated. Result: Analysis revealed that streets generally play as boundaries rather than territories, however, accessibility across the street, commercial facilities along the street, and some features such as mega-stores or cultural/sports facilities blurred the boundary and residents included the street as part of territory. This study confirmed findings from previous researches on urban territory and boundary, and can be introduced as the base information for future studies on neighborhood territory and eventually propose socially sustainable environments of urban planning and architecture.

Air Temperature Reductions at the Base of Tree Canopies.

Trees in urban settings have a significant role in regulating urban hydrologic cycles. Urban trees, either as standalone plantings or as part of a tree pit, are an increasingly popular stormwater management tool. Beyond their aesthetic contribution to urban environments, trees are widely accepted as reducing the ambient air temperature. However, there is limited long-term quantitative information regarding the temperature mitigation performed by urban trees through the use of temperature sensors over a large urban area. This study monitored air temperature at locations throughout the city of Camden, New Jersey. Sensors were installed under canopies of trees of different sizes throughout the city using a statistical experimental design. The tree size (small or large) and canopy (intersecting or nonintersecting), along with the street orientation (predominantly north-south or east-west) and time of day (daylight, nighttime, or full-day), were experimental design factors. Sensors attached to poles along the streets or in parking lots served as controls. This study recorded temperatures at 10-min intervals from early August through late November 2017 using logging thermistors mounted in radiation shields about 4 m above the ground surface. Using the maximum daily air temperature at control sites, all temperature data were categorized into three groups of hot, average, and cool days. The groups were analyzed separately using the analysis of variance to test the significance of the categorical variables. During hot days (a maximum temperature larger than 30°C), there was a meaningful statistical difference between recorded mean air temperatures under trees with intersecting canopies and the control sites. A categorical analysis of street orientation for hot and average days showed that during the daytime, east-west streets were hotter than north-south streets, while this trend reversed at night when north-south streets were hotter than east-west streets. For cool days, there were no differences for the studied categorical factors.

Experimental study on the thermal characteristics of urban mockups with different paved streets.

Pavements in urban area absorb more sunlight due to the canyon-like geomorphology of the urban geometry and store more heat due to the great thermal bulk properties of concrete. Heat released from pavements warms up the urban air, contributing to the urban heat island. Recently, the uses of cool pavements to reduce the pavement temperature as an urban heat island mitigation have gained momentum. Understanding the temperature and solar insolation of a pavement in an urban area is important to adopt the right cool pavement option for the right place. This study measured the temperature of paved streets in an urban mockup for 4 days in summer. It is found that east-west (EW) streets are the hottest place in an urban area, followed by the intersection, and finally the south-north (SN) street and that increasing the pavement's albedo reduces the pavement temperature effectively. The dark gray pavement in an open space is hotter than that in an urban canyon. The heat storage in the building blocks keeps the pavement warmer more than 2 °C at nighttime. The EW street is exposed to solar insolation for long hours, so it is suitable for preferentially developing reflective cool pavements.

Temperature of Paved Streets in Urban Mockups and Its Implication of Reflective Cool Pavements

In summer, urban heat islands increase building cooling demands, aggravate air pollution, and cause heat-related illnesses. As a mitigation strategy, reflective cool pavements have been deemed an effective measure to decrease the temperature in urban areas. However, the reflection of paved streets in an urban area will be different from that in an open area. It remains unknown which fraction of paved streets needs to be cooled upmost, and if increasing the albedo of paved streets can effectively reduce their temperature. This study measured the skin temperature of two urban mockups, of which one contained white streets and the other, gray streets. The streets were orientated at different strikes. It was found that in summer the East-West street was hotter than both the cross street and the South-North street. At nighttime, the heat released from building blocks kept the paved street about 0.2 °C hotter than paved areas in open spaces. It was also found that street orientation controlled the skin temperature of an urban street while the sky view factor (or building height and street width) acted in a secondary role only. Increasing the albedo of the paved street in an urban canyon effectively reduced the skin temperature of the street. Reflective pavements should be built preferentially on East-West streets and the cross streets.

High-Resolution Modelling of Thermal Exposure during a Hot Spell: A Case Study Using PALM-4U in Prague, Czech Republic

The modelling of thermal exposure in outdoor urban environments is a highly topical challenge in modern climate research. This paper presents the results derived from a new micrometeorological model that employs an integrated biometeorology module to model Universal Thermal Climate Index (UTCI). This is PALM-4U, which includes an integrated human body-shape parameterization, deployed herein for a pilot domain in Prague, Czech Republic. The results highlight the key role of radiation in the spatiotemporal variability of thermal exposure in moderate-climate urban areas during summer days in terms of the way in which this directly affects thermal comfort through radiant temperature and indirectly through the complexity of turbulence in street canyons. The model simulations suggest that the highest thermal exposure may be expected within street canyons near the irradiated north sides of east–west streets and near streets oriented north–south. Heat exposure in streets increases in proximity to buildings with reflective paints. The lowest heat exposure during the day may be anticipated in tree-shaded courtyards. The cooling effect of trees may range from 4 °C to 9 °C in UTCI, and the cooling effect of grass in comparison with artificial paved surfaces in open public places may be from 2 °C to 5 °C UTCI. In general terms, this study illustrates that the PALM modelling system provides a new perspective on the spatiotemporal differentiation of thermal exposure at the pedestrian level; it may therefore contribute to more climate-sensitive urban planning.

Effects of land use and vegetation on nighttime air temperature in heat vulnerable neighborhoods in New York City

Background: Climate change is projected to increase the frequency and duration of extreme heat days in New York City (NYC), increasing heat risks among vulnerable populations. A Heat Vulnerability Index (HVI) previously developed in NYC based on epidemiological analysis, facilitated the City’s heat mitigation initiatives (i.e. planting street trees in high heat-vulnerable neighborhoods). The initiative also allowed an assessment of the role of land-use and vegetation on air temperature variations within these neighborhoods. Methods:Nearly 500 temperature sensors were installed on street trees and light poles in 16 medium to high HVI neighborhoods, with approximately 35 sensors within each neighborhood of size up to 1 km2, during the summer of 2018. The average nighttime air temperatures (3 to 5 am) at these locations were modeled as a function of buffer-based (along street blocks) tree canopy, grass/shrubs, impervious surfaces, and buildings, allowing for non-linear relationships in a land-use regression model, adjusting for inter-neighborhood variations as a smooth function of XY coordinatesResults:With all predictors, the model R-squared was 71%. Street block level grass/shrub density was negatively associated with nighttime air temperature, with a ~0.8 degrees °C reduction within its range (0-25% cover). Street block level tree-canopy was also negatively associated with nighttime temperature, though it was strongly modified by street orientation: a ~0.4 degrees °C reduction for east-west streets over its range 0-60% cover, but null for north-south streets, likely influenced by both sunlight duration and wind patterns. Street block level impervious surface was positively associated with nighttime temperature, with ~0.2 degrees °C increase over its range of 5 to 50% coverage. Conclusions: In this high density, hyper-local temperature data measured in heat vulnerable neighborhoods, vegetative covers were associated with reductions in nighttime air temperatures. Parameters obtained from this study will be incorporated into modeling and projections for future heat mitigation planning.

East West Street: Then and Now

It is a great happiness to be with you today, and I am deeply honoured to be delivering the Lionel Cohen Lecture. That we should come together at the Hebrew University in Jerusalem, which I have had the great pleasure to visit on several occasions, stretching back many years, adds to the sense of personal significance.

Philippe Sands. “East West street. On the origins of Genocide and Crimes against Humanity

Philippe Sands. “East West street. On the origins of Genocide and Crimes against Humanity

Influence of ground surface boundary conditions on horizontal ground source heat pump systems

In this paper, the effects of ground surface boundary conditions, especially diurnal shading, on performance of horizontal ground source heat pump (GSHP) systems were studied. Firstly, a GSHP system model, which consists of the heat transfer of horizontal ground heat exchangers (GHEs) and the integration of the heat pump, and the ground surface boundary model are introduced. The diurnal shading model for canyon streets is also introduced. Then, effects of ground surface boundary conditions and shading on horizontal GSHP systems are studied. Results show that different assumptions on ground surface boundary conditions have significant impact on outcomes and should carefully be considered during analysing. The outlet fluid temperature and fluctuation in North-South (N-S) streets are higher than those of East-West (E-W) streets. The increase in street aspect ratios and latitudes could decrease sunshine exposure time of the streets. Daily variations of solar radiation and shading influence the outlet temperatures of horizontal GHEs up to buried depth of 2.5 m. Therefore, the effects of solar radiation and shading should be considered when studying shallow horizontal GHEs.

A field research on the impact of underlying surface configuration on street thermal environment in Lhasa

Commercial street is an important place for outdoor activities of urban residents. The quality of its thermal environment directly affects the comfort of pedestrians and the energy consumption of surrounding buildings. Block-scale microclimate studies have already been conducted in the context of different climates, while limited attention has been paid to the microclimate within high-altitude cold climate. Tibet, as the main body of the Qinghai-Tibet Plateau, presents typical plateau climate characteristics, and its unique natural climate conditions will certainly give birth to special urban environmental problems. Therefore, taking Lhasa as an example, this paper focuses on the impact of street thermal environment under different underlying surface configurations under unique plateau climate conditions. Based on the field measurement of the thermal environment of three streets in Lhasa City, namely, Yutuo Road, Duosen Road and Hongqi Road, the influence of different underlying surface design elements, namely, greening and water area, on the near ground microclimate and pedestrian comfort of the streets were analyzed. The analysis results of the measured datas show that: there are obvious temperature differences in the streets of different directions. Trees have a more significant cooling effect on East-West streets. The leaf area index (LAI) of trees will affect the improvement of thermal environment. Fountain has cooling effect in summer, but it is lower than that of trees. The research contents of this paper provides data basis for further research on the thermal environment and the optimization design of the underlying surface of the streets in the high altitude cold climate area.

Oona A. Hathaway and Scott J. Shapiro, The Internationalists. How a Radical Plan to Outlaw War Remade the World, New York, Simon & Shuster, 2017, pp. 581; Philippe Sands, East West Street. On the Origins of “Genocide” and “Crimes against Humanity”, London, Orion, 2016, pp. 496.

Oona A. Hathaway and Scott J. Shapiro, The Internationalists. How a Radical Plan to Outlaw War Remade the World, New York, Simon & Shuster, 2017, pp. 581; Philippe Sands, East West Street. On the Origins of “Genocide” and “Crimes against Humanity”, London, Orion, 2016, pp. 496.

Genocide at 70

On the anniversary of the Genocide Convention, it is useful that we look back at the history of the crime of genocide, its relationship with crimes against humanity and that we reflect on its relevance today.1 Over the last nine years, I have spent a significant amount of time grappling with these questions, whilst writing East West Street.2 The book is about the lives of individuals seeking to understand how their particular circumstances contributed to the roads they took and how the roads thus travelled changed the system of international law. Underneath this lurks a bigger question, a central question of identity: who are we? Are we individuals or members of a group? And how do we wish the law to protect us, as individuals or as members of a group?

Of Refugees and Resignation

Building on topics explored in East West Street: on the Origins of Genocide and Crimes against Humanity , this article traces the development and publication of James McDonald’s Letter of Resignation of League of Nations High Commissioner for Refugees. Expanding on events outlined in his book, Sands describes how the letter was published in 1935 as a political statement in the wake of emerging news about Nazi atrocities against the Jews and other minority groups. Drawing analogies between these events and the contemporary refugee crisis, he raises questions about the current legal, political and moral frameworks associated with refugees, calling for an end of the ‘closing of the doors’ mentality. For full text, please click here

MODERN SCHOLARS' VIEWS ABOUT THE CONTRIBUTION OF THE PROFESSOR H. LAUTERPACHT TO THE CREATION OF THE INTERNATIONAL BILL OF HUMAN RIGHTS AND ITS LEGAL ENFORCEMENT

This article examines Sir G. Lauterpacht’s respective contributions to contemporary international human rights law by concentrating on their European experience from their youth in Central Europe. Fiercely committed to the rule of law and holding the powerful to account, Lauterpacht was instrumental in bringing Nazi war criminals to justice, and his work forged the foundations of our modern human rights laws. Key to his contribution to the Human Rights Law was the belief that human rights could only be protected if powerful institutions were created to monitor and enforce them. Lauterpacht advocated a quasi-judicial body, similar to what became the European Commission on Human Rights. The articulation and recognition of human rights in international law was integral to his systematic defining and refining of the discipline through his academic and professional writings, which actively engaged contemporary legal theory and international relations debates. His corpus covered the breadth of international law through his authorship of major monographs and hundreds of articles and reviews. International scientific events that took place in the Lviv region are analyzed in this article (the international scientific conference «Legal concepts of H. Lauterpacht in the theory and practice of the International Law», series of scientific and memorial measures that took place in Lviv on November 9–12, 2017, organized by the non-governmental research center «Center for Urban History of East Central Europe» (director – Sofia Dyak). Program «Rights, Justice, and Memories of Lviv» (November 9–11, 2017) launched with lecture «Moving Beyond East West Street – Challenges for the Future and the Rule of Law» by Philippe Sands (the UCU Rule of Law Lecture Series) and continued on November 11 with unveiling of memorial plaques and art performance «East West Street: A Song of Good and Evil» at Lviv Philharmonic. This event brought together scholars from the fields of history, law, international law, and intellectual history. Among participants were: Markiyan Bem (European Court of Human Rights), Kateryna Busol (Global Rights Compliance), Norman Davies (University College London), (Franziska Exeler (Cambridge University / Free University in Berlin), Douglas Irvin-Erickson (GMU), Pieter Lagrou and Ornella Rovetta (Université Libre de Bruxelles), Louisa McClintock (Columbia University), Reut Paz (Giessen University), William Pomeranz (Kennan Institute), Philippe Sands (University College London), Mira Siegelberg (Queen Mary, University of London), Iryna Sklokina (Center for Urban History), Stefan Troebst (Leipzig University), and Natasha Wheatley (University of Sydney), Lori Damrosch (Columbia University), Sean Murphy (George Washington University), Gerry Simpson (London School of Economics and Political Science).