J. Duncan Whyatt

Effectiveness of Green Infrastructure for Improvement of Air Quality in Urban Street Canyons

Street-level concentrations of nitrogen dioxide (NO(2)) and particulate matter (PM) exceed public health standards in many cities, causing increased mortality and morbidity. Concentrations can be reduced by controlling emissions, increasing dispersion, or increasing deposition rates, but little attention has been paid to the latter as a pollution control method. Both NO(2) and PM are deposited onto surfaces at rates that vary according to the nature of the surface; deposition rates to vegetation are much higher than those to hard, built surfaces. Previously, city-scale studies have suggested that deposition to vegetation can make a very modest improvement (<5%) to urban air quality. However, few studies take full account of the interplay between urban form and vegetation, specifically the enhanced residence time of air in street canyons. This study shows that increasing deposition by the planting of vegetation in street canyons can reduce street-level concentrations in those canyons by as much as 40% for NO(2) and 60% for PM. Substantial street-level air quality improvements can be gained through action at the scale of a single street canyon or across city-sized areas of canyons. Moreover, vegetation will continue to offer benefits in the reduction of pollution even if the traffic source is removed from city centers. Thus, judicious use of vegetation can create an efficient urban pollutant filter, yielding rapid and sustained improvements in street-level air quality in dense urban areas.

Understanding the School Journey: Integrating Data on Travel and Environment

Travel to and from school is a regular part of life for most children. Such movement can also have important social, economic, and environmental implications, both for individuals and for wider society. This paper uses innovative methods to examine the complexity of the school journey, and to relate it to exposure to air pollution and engagement with the environment through which children pass. Some thirty lower secondary school pupils used mobile phone and global positioning system technology to record their routes to and from school in four study periods. They were asked to take photographs and write text messages relating to their route, and these data were then linked to modelled air pollution on the routes through which pupils travelled. Results demonstrate that for most children the journey to and from school is highly variable and contingent on other factors. Pupils who travelled independently (on foot, by bicycle, or by bus) were most likely to engage with their immediate environment, and small variations in route choice had significant effects on their cumulative exposure to air pollution. It is argued that the results shed new light on the everyday experience of the school journey, and have implications for health promotion and transport planning in towns.

Talk, technologies and teenagers: understanding the school journey using a mixed-methods approach

This paper focuses on the methods used in a project which set out to capture the movements and to consider the wellbeing of 30 teenagers on their journeys to and from school. A mobile phone linked to a GPS receiver was used to automatically log travel patterns whilst the respondents added ‘blog’ images and text about how they felt on the journey. Follow up interviews further explored the data. The paper shows that by using a range of methods the young people became involved in the project in different ways providing a rich picture of contingent and complex school journeys.

‘It’s just like an extra string to your bow’: Exploring higher education students’ perceptions and experiences of extracurricular activity and employability

Students’ experience of higher education comprises not only their academic studies but also their extracurricular activities. This article reports on the findings from a mixed-methods research project, exploring in detail the nature and value of extracurricular activity engagement and the significance of institutional schemes encouraging extracurricular activity engagement, from a UK student perspective. Our findings reveal that many students are actively engaged in a variety of extracurricular activities and recognise their value for employability. However, fewer students are strategic in their patterns of involvement, which may be hindered by a lack of career planning. Furthermore, extracurricular activity engagement can be detrimental to academic study, and engagement alone does not assure employability benefits. However, structured institutional schemes encouraging extracurricular activity engagement may facilitate reflection, enabling students to make best use of their experiences for their future careers. Our research contributes to a growing body of research evidence on ‘life-wide learning’.

Developing the desert: The pace and process of urban growth in Dubai

It is generally acknowledged that Dubai is a rapidly developing urban area which has grown to support a large human population within a hyperarid environment. However, no publicly accessible information exists concerning the rate or form of the urbanization process in Dubai. Therefore, this investigation used a time series of remotely sensed data to quantify land cover change in Dubai emirate between 1972 and 2011. A hybrid classification method accurately discriminated urban and other land covers, despite the challenging desert environment, and landscape metrics were used to quantify the spatial evolution of the emirate. The results indicate a dramatic increase in urban area, with a compound annual growth rate of 10.03% over the study period, with a peak of 13.03% during 2003-2005, making Dubai one of the fastest growing cities in the world. While the population growth rate was high, this has been outpaced by the rate of increase in urban area and the declining population density is indicative of urban sprawl. The spatiotemporal dynamics of urban growth are closely associated with prevailing local and global economic conditions and the ambitious development strategies of the government. Notable aspects of this growth include the substantial increase in vegetation and water bodies, and the unprecedented rate of construction of offshore islands. Dubai has undergone oscillating phases of urban diffusion and coalescence, but with much more rapid transitions than other cities. Superimposed on these phases are spatial patterns of development which have been recognised elsewhere, but the sequence of patterns appears unique to Dubai. This study has provided new insights into the pace and process of urban growth in Dubai. It is now important to evaluate the environmental consequences of this form of rapid urban development.

How reliable are citizen‐derived scientific data? : assessing the quality of contrail observations made by the general public

Citizen science projects encourage the general public to participate in scientific research. Participants can contribute large volumes of data over broad spatial and temporal frames; however the challenge is to generate data of sufficient quality to be useable in scientific research. Most observations made by citizen‐scientists can be independently verified by ‘experts’. However, verification is more problematic when the phenomena being recorded are short‐lived. This paper uses a GIS methodology to verify the quality of contrail observations made by the general public as part of the OPAL Climate Survey. We verify observations using datasets derived from a variety of different sources (experts, models and amateur enthusiasts) with different spatial and temporal properties which reflect the complex 3D nature of the atmosphere. Our results suggest that ~70% of citizen observations are plausible based on favourable atmospheric conditions and the presence or absence of aircraft; a finding which is in keeping with other, more conventional citizen science projects. However, questions remain as to why the quality of the citizen‐based observations was so high. Given the lack of supporting data on observers, it is impossible to determine whether the dataset was generated by the activities of many participants or a small but dedicated number of individual observers.

Satellite survey of gas flares: development and application of a Landsat-based technique in the Niger Delta

Pollution from oil and gas exploitation in the Niger Delta has greatly endangered the natural ecosystem, with gas flaring identified as a key agent of environmental pollution in the region. Efforts to evaluate the impacts of flaring on the surrounding environment have been hampered by limited access to official information on flare locations and volumes; hence, an alternative method of acquiring such information is needed. This article describes the development and application of the Landsat Flare Detection Method (LFDM), based on the combination of the near-, shortwave, and thermal infrared bands of Landsat imagery. The technique was validated using a reference data set of flare locations interpreted from aerial photographs, achieving a user accuracy of 86.67%. The LFDM was applied to a time series of imagery (1984–2012 inclusive) to obtain a long-term flaring history of the region; 303 flares (251 onshore and 52 offshore) were detected over the study period. The spatiotemporal distribution of these flares corresponds to known variations in oil and gas activities in the region. There was considerable variation between states in the trajectories of gas-flaring activity and the proportion of onshore vs. offshore flaring, which indicates substantial spatiotemporal variations in the environmental impacts of this industry. The LFDM builds upon existing methods of flare detection, which were based on moderate-resolution imagery, by offering increased precision of flare location estimates, improved objectivity, accurate identification of onshore and offshore flares, and a long flaring history. The LFDM is an efficient and cost-effective method that can provide local- to regional-scale information, which is complementary to that derived from other remote methods of flare detection and ground-based surveys. It could thus be used for backwards (flare history) and/or forwards (monitoring) surveys, especially in monitoring the country’s progress towards the recently set 30% flare reduction target by 2017.

Traits of plant communities in fragmented forests: the relative influence of habitat spatial configuration and local abiotic conditions

1. The plant trait composition of forest fragments is thought to be partly determined by forest spatial properties, although the relative importance of habitat configuration and local abiotic drivers is poorly understood. 2. To address this issue, large-scale habitat extent data were combined with detailed field survey information for temperate broad-leaved deciduous forest patches to quantify the relative effects of spatial and abiotic filters on plant community mean trait values. 3. Local conditions such as shade and soil fertility had the largest effect on mean trait values, but aspects of habitat configuration also had significant partial effects on a number of traits. 4. Mean trait values within older forest patches were more strongly influenced by forest spatial configuration than in younger patches. 5. Synthesis. Results indicate that, in addition to the effects of greater light availability and competition in small patches and at forest edges, aspects of habitat configuration such as patch size and isolation are themselves important factors limiting the occurrence of forest specialist species. Large areas of core forest habitat contain a greater proportion of rare, poor dispersing species, although these effects were less visible in more recently established forest. This highlights the importance of maintaining existing large and old forest patches as a refuge for forest specialist plants. The results of this comparison of spatial and abiotic variables suggest that controlling the spatial properties of forest patches is likely to prove an effective way of managing plant species diversity, provided that sites with appropriate abiotic conditions are chosen.

A Least‐Cost Approach to Personal Exposure Reduction

Concerns over the potential negative health effects from exposure to air pollution have led to interest in assessing personal exposure and finding ways to reduce it. As journey-time exposure accounts for a disproportionately high amount of an individual’s total exposure, this article assesses the potential to apply least-cost techniques within a GIS in order to identify paths of lower journey-time exposure. The methodology adopted uses pollution surfaces for PM10 and CO generated by the dispersion model ADMS, with an analysis mask derived from OS MasterMap to create a least-cost surface. Actual routes taken by a cohort of 11–13 year old children on their journeys to school are used to compare observed journey time exposure with the exposure along alternative routes generated using the least-cost path function. While the least-cost approach proved to be successful in defining low exposure routes the ability to scale up this approach is constrained by the amount of editing required to successfully create an analysis mask from OS MasterMap data. Such alternative routes have the potential to assist in promoting safer environmental choices, however, their likelihood of adoption is dependant on a number of social and environmental influences which affect an individual’s route choice.

‘It’s everything else you do…’: Alumni views on extracurricular activities and employability

This article explores students’ extracurricular activities and, uniquely, their short- and long-term effects on employability. Drawing on the literature, six research questions are identified. A questionnaire and interviews with alumni provide the quantitative and qualitative information needed. The effects of different extracurricular activities and the skills and qualities they promote are demonstrated for early- and later-career jobs, as are the complementary effects for employability of degree schemes and extracurricular activities. Alumni who are now recruiters of staff use their double perspective to explain the role extracurricular activities have played in their lives and now as professional recruiters. This article shows how the alumni of any university could share these insights with undergraduates.