Library Dissertation Showcase

How is the microclimate of Lincoln affected by the urban heat island effect?

  • Year of Publication:
  • 2022

Over recent decades, global temperatures and urbanisation have both been rising exponentially. This change in climate has been apparent through the increase in extreme weather events, which are amplified by urban areas. This cycle is creating a cause for concern for those living in urban areas, with potential harm being put on human wellbeing, the environment, the economy, and the energy sector. Previous work on the urban heat island (UHI) shows that urban areas amplify heat, mainly through the construction materials used in urban areas, as well as changing land use from natural vegetation to impervious surfaces, and through urban canopies preventing radiation from being reflected. Previous research therefore focuses on the larger, more densely populated cities, with expectations that these cities will show the largest UHI differences. Studies regarding the favourable conditions of the UHI, the night-time and summertime conditions, have also become increasingly common over the past 30 years. For this reason, there is a gap in research within the UK. This research focuses on Lincoln, a smaller-scale urban area, addressing the gap in current research regarding cities with much lower populations than those currently researched. The research also focuses on how the microclimate of this city is affected by different large scale weather conditions, different seasons, and different times of the day, other factors which currently do not have a large amount of data supporting them. In this study, air temperature, relative humidity and wind speed are all measured over a time span of 6 months, collected at 08:00 and 18:00. At the same time, using different equipment, air temperature is recorded every 5 minutes within this half a year data collection period. The study sites are divided between the urban and nonurban areas of Lincoln, with 3 in each area, covering as many possible different land uses and population densities. This research showed that the urban heat island is prominent in Lincoln, with it being present during every weather type, month, hour of the day, air pressure, and wind speed. The largest recorded UHI value is 4.09°C, while the average is 1.2°C, showing the effect the UHI has in Lincoln. Daily, the highest UHI value occurs at 21:00, due to the magnitude of cooling between the urban and nonurban areas. As is the case in other research, Lincoln does not see an urban cooling effect during the daytime, rejecting the proposal that smaller-scale urban areas have less prominent UHIs. Seasonally, summer sees the highest UHI, which is statistically significant from winter. Regarding weather types, anticyclonic conditions are favoured in the UHI in Lincoln, being highest on average in all locations, and during 4 of the 6 months analysed. This work shows that the UHI effect in smaller scale conditions can be just as prominent as in larger cities, and thus more studies need to be conducted in order to understand what can be done to mitigate against the warming of urban climates, as well as to lower the current UHIs that are already occuring. It also analyses the differences winter months and daytime conditions can show, increasing knowledge for times that while the UHI is at a lower intensity, it can still be fatal. This work can provide a basis for other, small-scale urban areas in the UK or with similar climates.

PLEASE NOTE: You must be a member of the University of Lincoln to be able to view this dissertation. Please log in here.