City Centre Site Research Articles

Spatial Distribution of Microplastics and Mesoplastics in Sediments across Hsinchu, Taiwan

Microplastics are becoming a major environmental concern, as they are ubiquitous, but their harm is not fully understood. Since research on microplastics in sediments in urban areas is scarce, this study aimed to uncover where microplastics may be the most abundant. City center, city border, and outer city sites were examined. One city center site was chosen (Gongshiyi Park), three city border sites were chosen (Touqian River North Bank, Touqian River South Bank, and Shixing Air Quality Purification Zone), and one outer city site was chosen (Shibajian Mountain). In each site, 25 samples were collected from an area of 10x10 cm and a depth of 2 cm, and plastic particles were filtered out using a 1mm sieve. The highest abundance of microplastics was at the city border (413.3 microplastics/m2), followed by the outer city (200 microplastics/m2), and lastly, the city center (100 microplastics/m2). Similarly, mesoplastics were collected and counted from the same samples, displaying a different trend with the highest abundance at the city border (273.3 mesoplastics/m2), followed by the city center (80 mesoplastics/m2), and lastly, the outer city (40 mesoplastics/m2). Contrary to previous research which showed a decrease in microplastic abundance from rural to urban areas, the findings of this study suggest that external anthropogenic variables, such as effective maintenance regimes, may have altered microplastic dispersal. Future studies should include a larger sample size, span over a longer period of time, and include a more complete land use analysis.

Does the High-Rise Building Typology meet the needs for City Densification? The case of Tirana, Albania

The first high-rise building ever in Tirana and Albania was built during the 70-s. This was Hotel Tirana or “15-kateshi” as it was nicknamed. At that time, Tirana was building not more than six floors high due to limitations in finances, technology, as well as seismic regulations. Hotel Tirana was an exception for ideological and symbolic reasons of the regime. After the ‘change’ of the early 90-s and the return of the market economy, several private construction companies came up by developing ‘tower’ typology buildings of 7-9 floors. In the second decade of transformations, the municipality developed several international architectural competitions, including a masterplan for the city centre (2003) and other specific construction sites, mainly for strategic high-rise building purposes. During these years, Tirana was densified by tripling its population thanks to a typology of towers of 9-11 floors. There has been a lot of criticism of the respective municipal decision-making procedures, allegedly related to the politicization and corruption of the verticalization and densification process via control of the building permissions system

Significant differences in black and brown carbon concentrations at urban and suburban sites

Light-absorbing carbonaceous particles (LAC) may cause and/or exacerbate non-communicable diseases, interfere with the Earth's radiative balance, darken urban buildings and impair vistas. In this study, we explored the temporal behaviour of LAC concentrations measured at wavelengths of 370 nm (brown carbon, BrC) and 880 nm (black carbon, BC) at two sites of a mid-sized city in Brazil. We observed sharp changes in LAC concentrations at the city centre site in response to variations in traffic volume. The highest concentrations were observed when winds originated from both the city core and from the direction of the bus terminal. The suburban site exhibited a notably uniform diurnal pattern and consistently lower LAC concentrations throughout the day. Nevertheless, substantial increases during the evening led to mean BrC and BC concentrations (2.6 and 2.2 μg m−3, respectively) comparable to daytime peaks observed in the city centre (3 μg m−3 and 2.5 μg m−3). This phenomenon was attributed to the burning of residential waste and overgrown vegetation in nearby vacant lots. Moreover, the highest concentrations coincided with periods of low wind speeds, usually linked to non-buoyant plumes from point sources. BrC concentrations surpassed BC concentrations, even at the city centre site. Not only was the Ångström absorption exponent (Å370/880) larger at the suburban site compared to the city centre (95th percentiles of 1.73 and 1.38, respectively), but it also exhibited a wider span. Overall, the combined LAC and Å370/880 data indicated that i) biomass burning is a major source of LAC at the suburban site; ii) at the city centre, bare BC particles may become internally mixed with BrC from biomass or fossil fuel emissions and enhance absorption at lower wavelengths. The occurrence of LAC peaks outside the evening rush hours suggests that other sources but on-road vehicular emissions may contribute to the deterioration of the air quality in the urban core. Tackling air quality across the urban perimeter requires targeting other potential sources but traffic emissions.

City-wide, high-resolution mapping of evapotranspiration to guide climate-resilient planning

The impacts of global change, including extreme heat and water scarcity, are threatening an ever-growing urban world population. Evapotranspiration (ET) mitigates the urban heat island, reducing the effect of heat waves. It can also be used as a proxy for vegetation water use, making it a crucial tool to plan resilient green cities. To optimize the trade-off between urban greening and water security, reliable and up-to-date maps of ET for cities are urgently needed. Despite its importance, few studies have mapped urban ET accurately for an entire city in high spatial and temporal resolution. We mapped the ET of Berlin, Germany in high spatial (10-m) and temporal (hourly) resolution for the year of 2019. A novel machine learning (ML) approach combining Sentinel-2 time series, open geodata, and flux footprint modeling was applied. Two eddy flux towers with contrasting surrounding land cover provided the training and testing data. Flux footprint modeling allowed us to incorporate comprehensive land cover types in training the ML models. Open remote sensing and geodata used as model inputs included Normalized Difference Vegetation Index (NDVI) from Sentinel-2, building height, impervious surface fraction, vegetation fraction, and vegetation height. NDVI was used to indicate vegetation phenology and health, as plant transpiration contributes to the majority of terrestrial ET. Hourly reference ET (RET) was calculated and used as input to capture the temporal dynamics of the meteorological conditions. Predictions were carried out using Random Forest (RF) regression. Weighted averages extracted from hourly ET maps using flux footprints were compared to measured ET from the two flux towers. Validation showed that the approach is reliable for mapping urban ET, with a mean R2 of 0.76 and 0.56 and a mean RMSE of 0.0289 mm and 0.0171 mm at the more vegetated site and the city-center site, respectively. Lastly, the variation of ET between Local Climate Zones (LCZs) was analyzed to support urban planning. This study demonstrated the capacity to map urban ET at an unprecedented high spatial and temporal resolution with a novel methodology, which can be used to support the sustainable management of green infrastructure and water resources in an urbanizing world facing climate change.

Energy and mass exchange at an urban site in mountainous terrain – the Alpine city of Innsbruck

Abstract. This study represents the first detailed analysis of multi-year, near-surface turbulence observations for an urban area located in highly complex terrain. Using 4 years of eddy covariance measurements over the Alpine city of Innsbruck, Austria, the effects of the urban surface, orographic setting and mountain weather on energy and mass exchange are investigated. In terms of surface controls, the findings for Innsbruck are in accordance with previous studies at city centre sites. The available energy is partitioned mainly into net storage heat flux and sensible heat flux (each comprising about 40 % of the net radiation, Q*, during the daytime in summer). The latent heat flux is small by comparison (only about 10 % of Q*) due to the small amount of vegetation present but increases for short periods (6–12 h) following rainfall. Additional energy supplied by anthropogenic activities and heat released from the large thermal mass of the urban surface helps to support positive sensible heat fluxes in the city all year round. Annual observed CO2 fluxes (5.1 kg C m−2 yr−1) correspond well to modelled emissions and expectations based on findings at other sites with a similar proportion of vegetation. The net CO2 exchange is dominated by anthropogenic emissions from traffic in summer and building heating in winter. In contrast to previous urban observational studies, the effect of the orography is examined here. Innsbruck's location in a steep-sided valley results in marked diurnal and seasonal patterns in flow conditions. A typical valley wind circulation is observed (in the absence of strong synoptic forcing) with moderate up-valley winds during daytime, weaker down-valley winds at night (and in winter) and near-zero wind speeds around the times of the twice-daily wind reversal. Due to Innsbruck's location north of the main Alpine crest, southerly foehn events frequently have a marked effect on temperature, wind speed, turbulence and pollutant concentration. Warm, dry foehn air advected over the surface can lead to negative sensible heat fluxes both inside and outside the city. Increased wind speeds and intense mixing during foehn (turbulent kinetic energy often exceeds 5 m2 s−2) help to ventilate the city, illustrated here by low CO2 mixing ratios. Radiative exchange is also affected by the orography – incoming shortwave radiation is blocked by the terrain at low solar elevation. The interpretation of the dataset is complicated by distinct temporal patterns in flow conditions and the combined influences of the urban environment, terrain and atmospheric conditions. The analysis presented here reveals how Innsbruck's mountainous setting impacts the near-surface conditions in multiple ways, highlighting the similarities with previous studies in much flatter terrain and examining the differences in order to begin to understand interactions between urban and orographic processes.

MITIGATION OF WASTE TRANSPORTATION COSTS IN TAIF PROVINCE, SAUDI ARABIA

Municipal solid waste (MSW) management is a critical issue in the Kingdom of Saudi Arabia (KSA). Management of solid waste in crowded conditions, especially in main cities such as the Al-Taif Province. This paper deals with that case study and focuses on how to solve material handling problems by applying conventional methods and computer ability. One of the costliest operations in the civil sector is transportation for material handling. City mayors considered transportation and materials handling as a subclass of the linear programming technique, thus linear programming problems take into consideration that the main objective is to handle materials from the city centre site to the identified dumping area. There are many methods and tools used to solve the transportation problem (TP) to find out the maximum or minimum in order to reduce cost or maximize profit. The methods related to manual solutions and others used many different computer applications. Manual solutions include the northwest corner method, the minimum cost method, the row minimum cost method, the column minimum cost method, and Vogel's approximation method, and computer applications such as LINGO, Lingo, and solver function using Microsoft Excel. This case study focuses on applying the Microsoft Excel function to find the minimum cost of the transportation system in waste materials to reduce the transportation cost from the city centre to the final destination (dumping area) to be used. The results achieved with the model aided in obtaining optimal solutions and finally, the optimal solutions were checked.

Multi-Temporal Change Detection Analysis of Vertical Sprawl over Limassol City Centre and Amathus Archaeological Site in Cyprus during 2015-2020 Using the Sentinel-1 Sensor and the Google Earth Engine Platform.

Urban sprawl can negatively impact the archaeological record of an area. In order to study the urbanisation process and its patterns, satellite images were used in the past to identify land-use changes and detect individual buildings and constructions. However, this approach involves the acquisition of high-resolution satellite images, the cost of which is increases according to the size of the area under study, as well as the time interval of the analysis. In this paper, we implemented a quick, automatic and low-cost exploration of large areas, for addressing this purpose, aiming to provide at a medium resolution of an overview of the landscape changes. This study focuses on using radar Sentinel-1 images to monitor and detect multi-temporal changes during the period 2015–2020 in Limassol, Cyprus. In addition, the big data cloud platform, Google Earth Engine, was used to process the data. Three different change detection methods were implemented in this platform as follow: (a) vertical transmit, vertical receive (VV) and vertical transmit, horizontal receive (VH) polarisations pseudo-colour composites; (b) the Rapid and Easy Change Detection in Radar Time-Series by Variation Coefficient (REACTIV) Google Earth Engine algorithm; and (c) a multi-temporal Wishart-based change detection algorithm. The overall findings are presented for the wider area of the Limassol city, with special focus on the archaeological site of “Amathus” and the city centre of Limassol. For validation purposes, satellite images from the multi-temporal archive from the Google Earth platform were used. The methods mentioned above were able to capture the urbanization process of the city that has been initiated during this period due to recent large construction projects.

When weight is an encumbrance; avoidance of stairs by different demographic groups.

Locomotion is an energy costly behaviour, particularly when it entails raising weight against gravity. Minimization of locomotor costs appears a universal default. Avoidance of stair climbing helps humans minimise their energetic costs. In public access settings, demographic subgroups that raise more 'dead' weight than their comparison groups when climbing are more likely to avoid stairs by choosing the escalator. Individuals who minimise stair costs at work, however, can accumulate a deficit in energy expenditure in daily life with potential implications for weight gain. This paper tests the generality of avoidance of stairs in pedestrians encumbered by additional weight in three studies. Pedestrian choices for stairs or the alternative were audited by trained observers who coded weight status, presence of large bags and sex for each pedestrian. Sex-specific silhouettes for BMIs of 25 facilitated coding of weight status. Choices between stairs and a lift to ascend and descend were coded in seven buildings (n = 26,981) and at an outdoor city centre site with the same alternatives (n = 7,433). A further study audited choices to ascend when the alternative to stairs was a sloped ramp in two locations (n = 16,297). Analyses employed bootstrapped logistic regression (1000 samples). At work and the city centre site, the overweight, those carrying a large bag and females avoided both stair climbing and descent more frequently than their comparison groups. The final study revealed greater avoidance of stairs in these demographic subgroups when the alternative means of ascent was a sloped ramp. Minimization of the physiological costs of transport-related walking biases behaviour towards avoidance of stair usage when an alternative is available. Weight carried is an encumbrance that can deter stair usage during daily life. This minimization of physical activity costs runs counter to public health initiatives to increase activity to improve population health.

Air quality trends of the Kathmandu Valley: A satellite, observation and modeling perspective

Kathmandu is the capital city of Nepal and a ‘hotspot’ of urban air pollution in South Asia. Its bowl-shaped structure (altitude 1300 m above sea level (masl); floor area 340 km2) surrounded by tall mountains provides a unique case study for analyzing pollution trapped by topography and local meteorology. In the absence of long-term in-situ observations, for the first time the columnar aerosol loading trend of the Kathmandu Valley was analyzed using satellite-derived aerosol optical depths (AOD). AOD from MODIS (Moderate Resolution Imaging Spectroradiometer) onboard Aqua and Terra (3 × 3 km, Level 2) was used during the dry season (November–June) in 2000–2015. Trend analysis of Kathmandu AOD (KAOD) (the Kathmandu Valley AOD (KValAOD) + background AOD (BAOD)) suggested an increase of ∼35% during the study period. To derive the KValAOD trend, BAOD was subtracted from KAOD. The KValAOD trend indicated an increase of ∼50–60% during the study period, based on MODIS Aqua and Terra data. Thereafter, the background contribution only at the valley layer (1300–1400 masl) was determined using Cloud-Aerosol LiDAR and Infrared Pathfinder Satellite Observation (CALIPSO) profiles, in-situ observation and modeling techniques. The CALIPSO-based analysis indicated that background pollution contributed an additional 20–25% to local pollution. This finding was further supported by short-term in-situ measurements from Dhulikhel (the site where Kathmandu background measurements were taken) and Ratnapark (a Kathmandu city center site). Case studies were conducted using chemical transport models (WRF-STEM and WRF-Chem) to quantify the contribution of background air pollution to the Kathmandu valley pollution. These model results contradicted the satellite and in-situ observation by highly underestimating the Kathmandu Valley pollution levels. Comparison of visibility in Kathmandu with AOD suggests a profound role of BAOD on decreasing long-distance visibility in particular months.

Eddy covariance measurements of the net turbulent methane flux in the city centre – results of 2-year campaign in Łódź, Poland

Abstract. To investigate temporal variability of methane (CH4) fluxes in an urban environment, air–surface exchange fluxes of CH4 were continuously measured using eddy covariance techniques at a city-centre site in Łódź, Poland, from July 2013 to August 2015. In the immediate vicinity of the measurement site, potential methane sources include vehicle traffic, dense sewerage infrastructure and natural gas networks. Sensible and latent heat fluxes have also been measured since 2000 and carbon dioxide fluxes since 2007 at this site. Upward CH4 fluxes dominated during the measurement period, indicating that the city centre is a net source of CH4 to the troposphere. The highest monthly fluxes were observed in winter (2.0 to 2.7 g m−2 month−1) and the lowest in summer (0.8 to 1.0 g m−2 month−1). Fluxes on working days were around 6 % higher than on weekends. The cumulative flux indicates that the city centre emitted a net quantity of nearly 18 g m−2 of CH4 in 2014. Stable values of the FCO2∕ FCH4 ratio in months (minimum 2.41 × 10−3, maximum 5.3 × 10−3) and the lack of a clear annual course suggest comparable magnitude of both fluxes.

Characteristics of atmospheric PM2.5 in stands and non-forest cover sites across urban-rural areas in Beijing, China

Monitoring air pollution at a city scale is essential for controlling urban air pollution in cities, especially megacities, in China. In this paper, data for 1 city center site and 5 paired (stands and non-forested) PM2.5 monitoring sites across urban-rural areas in Beijing were collected, and air PM2.5 and influential factors were analyzed. The results showed that the mean value of PM2.5 (February to December 2013) was lower in the stands (67.00 μ gm �3 ) than in the non-forested sites (78.02 μ gm �3 ). The diurnal variation was a bimodal double-dip type, and the average daily PM2.5 was lower in the vegetation areas than in the non-vegetation areas in both Changping Dingling (vegetation) and Changping town (non-vegetation) and showed day > night. In the typical pollution process, accompanied by an increase or decrease in PM2.5 and air quality index values, the higher the PM2.5, the lower the wind speed. PM2.5 in the vegetation areas lagged behind PM2.5 in the non-vegetation areas on typical sunny days but not on typical rainy and windy days. On typical sunny days, the variation of PM2.5 in the vegetation areas was less than that in the non-vegetation areas. PM2.5 did not change significantly under rainy conditions and before a rain, but the variation was smaller after a

The Air Quality, Characterization of Polycyclic Aromatic Hydrocarbon, Organic Carbon, and Diurnal Variation of Particulate Matter over Riyadh City

Concentrations of airborne particulate matter (PM10 & PM2.5) were measured over a period extended from January 2012 to October 2013 at two sites: a suburban area, Riyadh airport (AP) and an urban area, King Fahd road district (KF) (densely trafficked site) in Riyadh city, Saudi Arabia. The quality of ambient air using the U.S. Environmental Protection Agency (USEPA) Air Quality Index (AQI) was evaluated during this period. The average AQI values exceeded 100 on 6 months out of 11 in AP district. At KF district the condition was worse, and AQI values exceeded 100 on all months. This emphasizes the fact that PM concentrations over Riyadh can be regarded as a real environmental problem that could be a severe risk to quality of life and threaten human health. A higher-volume air sampler at the two sites was used to collect particulate matter (PM10 and PM2.5) for chemical analysis of the PM for PAHs and total organic carbon. At KF station the mean concentrations’ values of total PAHs in PM2.5 and PM10 were 4.89 ng/m3 and 12.96 ng/m3 respectively. At the AP station the corresponding values of total PAHs in PM2.5 and PM10 were 8.07 ng/m3 and 11.91 ng/m3 respectively. The PAHs did not exceed the air criteria of World Health Organization indicating the air pollution of PAHs in Riyadh District was not serious. As for the total organic carbon the results demonstrated that the concentration ranged from 0.211 to 0.506 g/kg at KF station and from 0.054 to 0.342 g/kg at AP station. On an annual basis, OC concentrations were two times higher for the city center site (KF) compared to the rural AP site. This can most likely be explained by increased emissions from higher traffic at KF site. The diurnal variability of PM was mainly associated with the severity of pollution.

A new composite flooring solution for the Leadenhall Building, UK

The construction of the Leadenhall Building in London, UK has presented many challenges to the project team due to its distinct geometry and constrained city centre site. Conventional construction techniques would have resulted in a slow build programme, and caused major disruption to the local environment. Hence contractor Laing O’Rourke developed a new composite flooring solution for the project in collaboration with Arup and BRE, consisting of lightweight precast concrete elements that were dowelled and grouted together integrally with the supporting steelwork. This paper presents the new patented solution that was developed and the research and development that was undertaken to demonstrate its technical viability. Small-scale shear and bond tests, and large-scale load and dynamic testing were undertaken to demonstrate the system’s performance against the technical requirements defined for the project by the clients, British Land and Oxford Properties. Lessons learnt from manufacturing, installation and on-site dynamics testing are discussed.

Phagocytosis of fossil fuel particulates by macrophages in children with asthma

BackgroundAirway macrophages clear inhaled soot (black carbon) from traffic fumes. Macrophages from children with asthma have impaired phagocytosis of bacteria, and prostaglandin E2 (PGE2) is associated with impaired phagocytosis by macrophages. We sought to assess whether macrophage phagocytosis of soot was impaired, and to measure prostanoid metabolites, in children with asthma. MethodsIn this cross-sectional study, airway macrophages were obtained from 72 children aged 7–14 years by sputum induction with nebulised 4·5% saline. Children were classified as: healthy controls (n=39); mild asthma, defined as British Thoracic Society (BTS) step 1–2 (n=13); or moderate-to-severe asthma (BTS step 3–5) (n=20), and recruited from a UK paediatric outpatient clinic. Healthy controls were recruited as part of the London Low Emission Zone study. Macrophage black carbon was assessed with image analysis by an assessor masked to asthma severity. Exposure to air pollution was calculated by means of the London Air Quality Toolkit. Urinary PGE2 metabolites were measured with high performance liquid chromatography-tandem mass spectrometry. The effect of PGE2 on phagocytosis of black carbon by rat airway macrophages was assessed with an in-vitro phagocytosis assay using urban particulate matter collected from air filters placed at city centre sites in Leicester, UK. Written informed consent was obtained from children and parents (Research Ethics Committee reference 11-LO-1732 and 08/H0704/139). FindingsChildren with moderate-to-severe asthma had lower airway macrophage black carbon than did controls (median 0·19 mm2 [IQR 0·11–0·26] vs 0·35 [0·16–0·49], p<0·0366, Mann-Whitney U test). Airway macrophage black carbon in children with mild asthma was much the same as in controls. Air pollution exposure at the home address did not differ between groups. Moderate to severe asthma was associated with an increase in the urinary PGE2 metabolite, 13,14-dihydro-15-keto-tetranor-PGE2 (median 668 pg/mg creatinine [IQR 293–937] vs 471 [315–623], p<0·05, Mann-Whitney U test). In the 33 children with asthma, this urinary PGE2 metabolite was inversely associated with macrophage carbon (Spearman r =−0·47, p<0·0062). PGE2 suppressed phagocytosis by rat airway macrophages of urban particulate matter to 57% (IQR 41–95) of controls (p<0·0215, Wilcoxon signed rank test). InterpretationMacrophage phagocytosis of black carbon derived from fossil fuel is impaired in moderate-to-severe childhood asthma. This process is associated with raised urinary concentrations of 13,14-dihydro-15-keto-tetranor-PGE2. PGE2 also impairs phagocytosis of black carbon and urban particulate matter by rat airway macrophages in vitro, and is therefore a plausible mediator underlying the impaired phagocytosis seen in macrophages from children with asthma. We now aim to replicate these findings in differentiated human macrophages and to establish airway concentrations of PGE2 from exhaled breath condensate samples taken from these children. Our results suggest a possible mechanism underlying the observation that traffic-derived air pollution adversely affects children with asthma, because they may be less able to clear inhaled particles effectively. FundingBarts and The London Charity.

Risk assessment and spatial chemical variability of PM collected at selected bus stations

The chemical characterization of particulate matter inside and outside of confined bus shelters has been discerned for the first time. Transit patrons are at risk due to the close vicinity of densely trafficked areas resulting in elevated pollution footprints. Incomplete combustion processes, as well as exhaust and wear and tear emissions from public and personal transportation vehicles, are key contributors to degraded urban air quality and are often implicated as causal to various diseases in humans. Urban planning, therefore, includes efficient public transport systems to mitigate the effect. The bus rapid transit system was inaugurated in Curitiba to ensure dedicated traffic lanes, major bus interchanges and semi-confined bus stops called “tube stations”. To assess the chemical risk that the passengers are exposed to, an investigation of the aerosol inside and outside five of these tube stations was launched. Electron probe X-ray micro-analysis and X-ray fluorescence were used to determine the elemental composition of individual and of bulk particle samples. An aethalometer quantified the black carbon. Elemental concentrations inside the shelters were in general higher than outside, especially for traffic-related elements. The lead concentration exceeded the NAAS standard at times, although the average was below the guideline. The biogenic, organic and soot clusters showed the highest abundance for the city centre sites. The overall carcinogenic risk could be classed as moderate, and the risk was significant at two sites during one of the sampling campaigns. The non-carcinogenic risk is well below the significant value.

An hourly PM10 diagnosis model for the Bilbao metropolitan area using a linear regression methodology

There is extensive evidence of the negative impacts on health linked to the rise of the regional background of particulate matter (PM) 10 levels. These levels are often increased over urban areas becoming one of the main air pollution concerns. This is the case on the Bilbao metropolitan area, Spain. This study describes a data-driven model to diagnose PM10 levels in Bilbao at hourly intervals. The model is built with a training period of 7-year historical data covering different urban environments (inland, city centre and coastal sites). The explanatory variables are quantitative-log [NO2], temperature, short-wave incoming radiation, wind speed and direction, specific humidity, hour and vehicle intensity-and qualitative-working days/weekends, season (winter/summer), the hour (from 00 to 23 UTC) and precipitation/no precipitation. Three different linear regression models are compared: simple linear regression; linear regression with interaction terms (INT); and linear regression with interaction terms following the Sawa's Bayesian Information Criteria (INT-BIC). Each type of model is calculated selecting two different periods: the training (it consists of 6 years) and the testing dataset (it consists of 1 year). The results of each type of model show that the INT-BIC-based model (R(2) = 0.42) is the best. Results were R of 0.65, 0.63 and 0.60 for the city centre, inland and coastal sites, respectively, a level of confidence similar to the state-of-the art methodology. The related error calculated for longer time intervals (monthly or seasonal means) diminished significantly (R of 0.75-0.80 for monthly means and R of 0.80 to 0.98 at seasonally means) with respect to shorter periods.

Seismic behaviour of pile in three-layered soil (case study: Babol City Center Project)

The significance of liquefaction-related damage to pile foundations has been clearly demonstrated by the major earthquakes occurring during past years. The current project investigates the seismic behaviour of a single pile in the three-layered soil of the Babol City centre site (located in Babol City, Mazandaran Province, Iran). The site soil consists of sandy and clayey soils modelled based on the data collected from drilled boreholes. Numerical analysis was performed using Flac2D finite difference program. Three different natural ground motion records are considered, and the influence of each earthquake on the bending moment and lateral displacement of the simulated pile is investigated. In addition, the effect of vertical surcharge on the settlement of the pile during the earthquakes is investigated. Results illustrate that the maximum bending moment has occurred on the interface of liquefiable and non-liquefiable soil layers.

A low-order canyon model to estimate the influence of canyon shape on the maximum urban heat island effect

A simple mathematical model of an urban canyon is developed. The canyon model consists of horizontal and vertical slabs providing thermal storage for heat and absorption of and shielding from solar radiation and long wave radiation to the sky. The model is compared to a horizontal slab in a rural location to examine the effect of the canyon shape. The results show the same trend as measurements by others, with increasing urban heat island (UHI) effect with increasing canyon aspect ratio. The model is then used to determine the maximum UHI effect by producing a simple algebraic equation. This compares well with measurements in Greater Manchester of canyon and rural temperatures although some empirical adjustments are required. The strong influence of cloud cover is shown by the model and measurements as are the canyon shape and the ground temperature. Practical applications: The model is simple and developed in terms applicable to building services engineers, using ventilation rates through the canyon. It also does not require more than the standard weather data available in a CIBSE Test Reference Year or a Design Summer Year. From this model, the UHI effect can be developed to adjust the data from a rural site to that of an urban and city centre site. This is useful for building designers to take account of the UHI effect which they cannot do at present. This would also be useful for UKCP09 data which have been released.

Strata SE1, London – propelling sustainable regeneration

Strata SE1 is a new 43-storey, 148 m tall reinforced concrete residential tower leading the sustainable regeneration of the Elephant and Castle area in London, UK. With a curved triangular footprint and three 9 m diameter wind turbines, the tower has been designed economically and built quickly on a confined city centre site. This paper describes the design and construction of the project, which used a system of ‘walking columns’ to achieve its tapered shape, with slabs acting as struts and ties. Headed reinforcement bars were used within the ties – one of the first applications in a UK building.

Ashmolean Museum, Oxford

AbstractIn November 2009, the Ashmolean Museum opened a new extension that doubled its gallery space on its existing city centre site. Howard Watson looks at how the redevelopment of the museum has been to its benefit curatorially, optimising the display space available for its extensive collections, but also enabling new connections to be made between artefacts in a way that fully tells the stories of civilisations across the globe. Copyright © 2010 John Wiley &amp; Sons, Ltd.