Urbanisation-induced climate warming in Great Britain

<p>In Great Britain (GB) 5.8% of the total land area is considered urban, yet the wider impact of Urban Heat Islands (UHIs) beyond city scales has not been fully explored. Through scaling data from a high-resolution urban monitoring network we estimate the current (2014) spatial daily-mean urban warming across GB to be 0.04&#176;C [0.02 &#176;C &#8211; 0.06&#176;C]. Despite this GB-wide contribution appearing small (94% of the land cover is still rural), half of GB's population currently live in areas with average daily-mean UHIs of 0.4&#176;C. GB is also experiencing rapid urbanisation, with urban land cover expanding from 4.3 to 5.8% between 1975 and 2014. Purely due to urbanisation in this period, we estimate GB as a whole is warming at a rate that is both equivalent and in addition to ~3% of the background surface-level climate change (i.e. natural and greenhouse gas induced). In areas with the greatest urban expansion, we find UHI-induced warming rates are up to three times this average. Although our study only applies to GB, the simplicity of our method means that it can be equally applied to other countries. Urbanisation is undeniably a global phenomenon with urban expansion in many countries far exceeding that found in GB.</p>

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A Quantitative Assessment of Surface Urban Heat Islands Using Satellite Multitemporal Data over Abeokuta, Nigeria

International Journal of Atmospheric Sciences ◽

10.1155/2016/3170789 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

K. A. Ishola ◽

E. C. Okogbue ◽

O. E. Adeyeri

Keyword(s):

Land Cover ◽

Urban Expansion ◽

Regional Scale ◽

Thermal Response ◽

Urban Heat Islands ◽

Rapid Urbanization ◽

Land Cover Types ◽

Remarkable Effect ◽

Heat Islands ◽

Urban Heat

The fast urban expansion has led to the transformation of the natural landscape into anthropogenic surfaces. The city of Abeokuta, for instance, is located in a region experiencing rapid urbanization, which has produced a remarkable effect on the surface thermal response. This effect significantly influences urban internal microclimatology on a regional scale. In this study, the surface temperatures and land cover types retrieved from Landsat TM and ETM+ images of Abeokuta city for 1984, 2003, and 2014 were analyzed. A quantitative approach was used to assess surface urban heat islands through the relationships among surface temperature and land cover types. Results showed that impervious surface areas were found to be correlated positively with high temperatures. Conversely, vegetated areas and bare surfaces correlated positively with mid temperature zones. This study found that areas with increasing impervious surfaces will accelerate LST rise and consequently lead to increasing effect of surface urban heat islands. These findings pose a major challenge to urban planners. However, the study would help to quantify the impacts of different scenarios (e.g., vegetation loss to accommodate urban growth) on LST and consequently to devise appropriate policy measures.

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Spatiotemporal Influence of Land Use/Land Cover Change Dynamics on Surface Urban Heat Island: A Case Study of Abuja Metropolis, Nigeria

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10050272 ◽

2021 ◽

Vol 10 (5) ◽

pp. 272

Author(s):

Auwalu Faisal Koko ◽

Wu Yue ◽

Ghali Abdullahi Abubakar ◽

Akram Ahmed Noman Alabsi ◽

Roknisadeh Hamed

Keyword(s):

Land Use ◽

Land Cover ◽

Land Surface ◽

Urban Expansion ◽

Urban Heat Islands ◽

Sustainable Land Use ◽

Land Use Land Cover ◽

Urban Centers ◽

Rapid Urbanization ◽

Urban Heat

Rapid urbanization in cities and urban centers has recently contributed to notable land use/land cover (LULC) changes, affecting both the climate and environment. Therefore, this study seeks to analyze changes in LULC and its spatiotemporal influence on the surface urban heat islands (UHI) in Abuja metropolis, Nigeria. To achieve this, we employed Multi-temporal Landsat data to monitor the study area’s LULC pattern and land surface temperature (LST) over the last 29 years. The study then analyzed the relationship between LULC, LST, and other vital spectral indices comprising NDVI and NDBI using correlation analysis. The results revealed a significant urban expansion with the transformation of 358.3 sq. km of natural surface into built-up areas. It further showed a considerable increase in the mean LST of Abuja metropolis from 30.65 °C in 1990 to 32.69 °C in 2019, with a notable increase of 2.53 °C between 2009 and 2019. The results also indicated an inverse relationship between LST and NDVI and a positive connection between LST and NDBI. This implies that urban expansion and vegetation decrease influences the development of surface UHI through increased LST. Therefore, the study’s findings will significantly help urban-planners and decision-makers implement sustainable land-use strategies and management for the city.

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Analysis of land use/land cover change, population shift, and their effects on spatiotemporal patterns of urban heat islands in metropolitan Shanghai, China

Applied Geography ◽

10.1016/j.apgeog.2013.07.021 ◽

2013 ◽

Vol 44 ◽

pp. 121-133 ◽

Cited By ~ 165

Author(s):

Hao Zhang ◽

Zhi-fang Qi ◽

Xin-yue Ye ◽

Yuan-bin Cai ◽

Wei-chun Ma ◽

...

Keyword(s):

Land Use ◽

Land Cover ◽

Land Cover Change ◽

Spatiotemporal Patterns ◽

Urban Heat Islands ◽

Land Use Land Cover ◽

Heat Islands ◽

Urban Heat ◽

Population Shift

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Effect of Land Cover Fractions on Changes in Surface Urban Heat Islands Using Landsat Time-Series Images

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16060971 ◽

2019 ◽

Vol 16 (6) ◽

pp. 971 ◽

Cited By ~ 4

Author(s):

Tao Chen ◽

Anchang Sun ◽

Ruiqing Niu

Keyword(s):

Land Cover ◽

Urban Heat Island ◽

Land Surface ◽

Urban Heat Islands ◽

Urban Heat Island Intensity ◽

Heat Island ◽

Impervious Surfaces ◽

Heat Islands ◽

Urban Heat ◽

Surface Urban Heat Island

Man-made materials now cover a dominant proportion of urban areas, and such conditions not only change the absorption of solar radiation, but also the allocation of the solar radiation and cause the surface urban heat island effect, which is considered a serious problem associated with the deterioration of urban environments. Although numerous studies have been performed on surface urban heat islands, only a few have focused on the effect of land cover changes on surface urban heat islands over a long time period. Using six Landsat image scenes of the Metropolitan Development Area of Wuhan, our experiment (1) applied a mapping method for normalized land surface temperatures with three land cover fractions, which were impervious surfaces, non-chlorophyllous vegetation and soil and vegetation fractions, and (2) performed a fitting analysis of fierce change areas in the surface urban heat island intensity based on a time trajectory. Thematic thermal maps were drawn to analyze the distribution of and variations in the surface urban heat island in the study area. A Multiple Endmember Spectral Mixture Analysis was used to extract the land cover fraction information. Then, six ternary triangle contour graphics were drawn based on the land surface temperature and land cover fraction information. A time trajectory was created to summarize the changing characteristics of the surface urban heat island intensity. A fitting analysis was conducted for areas showing fierce changes in the urban heat intensity. Our results revealed that impervious surfaces had the largest impacts on surface urban heat island intensity, followed by the non-chlorophyllous vegetation and soil fraction. Moreover, the results indicated that the vegetation fraction can alleviate the occurrence of surface urban heat islands. These results reveal the impact of the land cover fractions on surface urban heat islands. Urban expansion generates impervious artificial objects that replace pervious natural objects, which causes an increase in land surface temperature and results in a surface urban heat island.

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