The effect of spatial settlement patterns on urban climatology

Abdulrasheed, Mukhtar (2021). The effect of spatial settlement patterns on urban climatology. University of Birmingham. Ph.D.

Preview

Abdulrasheed2021PhD.pdf
Text - Accepted Version
Available under License All rights reserved.
Download (10MB) | Preview

Abstract

Increasing urbanization, in addition to driving climate change and pollution, can have a profound effect on the ecosystem properties within and even far from urban areas. As such, it is important to understand the energy balance of cities including the extent of its modification by urban form. This PhD thesis examines the effect of spatial settlement pattern on urban climatology. The initial study focussed on UK overpasses of the Moderate Resolution Imaging Spectro-radiometer (MODIS) satellite instrument, covering the period between 2000 and 2017, were sampled to examine the seasonal (winter and summer) night-time clear-sky upwelling long-wave energy for 35 UK cities. Total (area-summed) emitted energy was calculated per city. Well-defined (R2≥0.79) and robust ‘allometric’ scaling against city population was found for all samples. Total night-time emitted energy is found to scale sub-linearly with population on both summer and winter nights, with slope of 0.85±0.03. The scaling of night-time emitted energy with urban areas is close to linear (1.0±0.05). This indicates that UK Cities, although often appearing superficially very different, are similar in their gross thermal properties, i.e., in terms of the components of urban form, which dictate thermal properties. A case study of Nigeria’s cities on allometric scaling of emitted energy with population is also investigated, and it turned out to be very different from the UK study with slope of 0.41±0.05. Nigerian cities show much more sub-linear allometric scaling of total emitted energy with population, indicating slightly economy of scale in terms of nocturnal heat production. Local climate zones are further used to interpret results from the study. The study went further to investigate how the sum measure of the spatial distribution of emitted energy inside the city’s boundary is affected by the urban morphology, using the previous UK study. A fitted distribution of both extremes’ percentiles of emitted energy and land use maps within city were used as basis for comparison across cities in order to delineate the hottest and coldest spots in the distribution of long-wave energy for a sample night.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):