NERC GW4+ DTP PhD project: Optimising the Distribution of Green Infrastructure in Urban Areas

This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP) for entry in October 2023. The GW4+ DTP consists of the Great Western Four alliance of the Universities of Bath, Bristol and Exeter and Cardiff University plus five prestigious Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology & Hydrology, the Natural History Museum and Plymouth Marine Laboratory. The partnership aims to provide a broad multi-disciplinary training, designed to produce tomorrow’s leaders in earth and environmental science.

Supervisory Team:

Lead Supervisor: (Tristan Kershaw, University of Bath, Architecture and Civil Engineering) 

Co-Supervisor: (Kevin Gaston, University of Exeter, Environment and Sustainability Institute) 

Project Background 

It has long been known that cities and urban areas exhibit their own climate, being typically warmer than their surroundings especially at night. This urban heat island effect which can be likened to a bubble of warm air sat over a city, traps heat and pollutants at street level. The urban heat island of cities such as London has been measured to be 7°C on average and increasing to ~10°C during heat wave events increasing the risk of heat related illness and death. With the world rapidly urbanising the number of large, dense cities with substantial heat islands is increasing. Measures to reduce the urban heat island are poorly formed and vague, with suggestions such as simply increasing the amount of green (vegetation) and blue (waterbodies) space in an urban environment to increase evapotranspiration and vertical transport of heat and air. There is no guidance about the size geometry or location of green infrastructure required to mitigate an urban heat island or how any cooling effect may change in the future due to changes in urban density or background climate. There is research linking peoples’ health and wellbeing to feeling a connection to nature, add to this the positive benefits of increased biodiversity and providing space for recreation and the benefits of green infrastructure become many fold. However, in cities space is at a premium, so simply creating more green infrastructure is not feasible. This project will consider how best to deploy green infrastructure across a city to produce the optimal amount of cooling, increases to biodiversity and ecosystem services while minimising the cost in terms of space.  

Project Aims and Methods 

As a starting point it is expected that the student will identify a case study location and examine the current level of biodiversity within the urban area, the level of walkability and the amount of environmental capital available in the city and identify the magnitude of the urban heat island either from published data or as a result of simulations. It is then envisaged that the student will undertake a parametric study of different permutations of green infrastructure deployed across the city to reduce the heat island effect, reducing urban temperatures, alleviating air pollution while providing ecosystem services to improve the health and wellbeing of city occupants whilst minimising the impact of land prices. Cities are often devoid of wildlife and a key component of this project will be balancing the typologies of green infrastructure (size, shape, location and plant species) to increase biodiversity whilst manipulating the urban surface roughness and convective heat loss. This principally theoretical project will make use of urban modelling software such as PALM 4U, ENVImet or Ladybug/Dragonfly.  

Key questions include: 

• How much green infrastructure is required to dissipate the heat island effect? 
• How should green infrastructure be deployed across a cityscape? Should green infrastructure be deployed to form green corridors for greater walkability and species migration, or are discrete large parks better in terms biodiversity, ecosystem services and ultimately human health and wellbeing.  
• How does the scenario change as a city continues to grow and the size and geometry of the surroundings buildings changes.  

Research is fluid and there are opportunities for the student to shape this project as they see fit and pursue new avenues as they arise.  

Candidate requirements 

Applicants for a studentship must have obtained, or be about to obtain, a UK Honours degree at 1^st or 2.1 level, or international equivalent. A knowledge of urban climate studies, environmental science, climate modelling or ecology would be beneficial.

Non-UK applicants must meet the programme’s English language requirement by 01 February 2023 (the only exemption is if you will be awarded a UK degree or degree conducted in English before your PhD start date).

Project partners  

This project is an exciting collaboration between the Dept. of Architecture and Civil Engineering at the University of Bath and the Environment and Sustainability Institute at the University of Exeter. Bath has been named The Times University of the Year 2023 and is currently ranked 1st for Architecture. The Environment and Sustainability Institute leads world class research into environmental change, ecosystem dynamics and biodiversity renewal.

Enquiries and Applications:

Informal enquiries are welcomed and should be directed to Dr Tristan Kershaw, [Email Address Removed]

Formal applications should be made via the University of Bath's online application form for a PhD in Civil Engineering.

When completing the form, please identify your application as being for the NERC GW4+ DTP studentship competition in Section 3 Finance (question 2) and quote the project title and lead supervisor’s name in the ‘Your research interests’ section. 

More information about applying for a PhD at Bath may be found on our website.

We welcome and encourage student applications from under-represented groups. We value a diverse research environment. If you have circumstances that you feel we should be aware of that have affected your educational attainment, then please feel free to tell us about it in your application form. The best way to do this is a short paragraph at the end of your personal statement.

Project keywords: (built environment, biodiversity, climate science)

A suitable background to this topic can be found in this open access publication Utilising green and bluespace to mitigate urban heat island intensity