Urban form strongly mediates the allometric scaling of airshed pollution concentrations
We present allometric-scaling relationships between non-point-source emissions of air pollutants and settlement population, using 3030 urban settlements in Great Britain (home to ca. 80% of the population of that region). Sub-linear scalings (slope < 1.0; standard error on slope ∼0.01; r ^2 >...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2019-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ab50e3 |
| _version_ | 1797747926717431808 |
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| author | A R MacKenzie J D Whyatt M J Barnes G Davies C N Hewitt |
| author_facet | A R MacKenzie J D Whyatt M J Barnes G Davies C N Hewitt |
| author_sort | A R MacKenzie |
| collection | DOAJ |
| description | We present allometric-scaling relationships between non-point-source emissions of air pollutants and settlement population, using 3030 urban settlements in Great Britain (home to ca. 80% of the population of that region). Sub-linear scalings (slope < 1.0; standard error on slope ∼0.01; r ^2 > 0.6) were found for the oxides of nitrogen (NO _x ) and microscopic airborne particles (PM _10 and PM _2.5 ). That is, emissions of these pollutants from larger cities are lower per capita than would be expected when compared to the same population dispersed in smaller settlements. The scalings of traffic-related emissions are disaggregated into a component due to under-use of roads in small settlements and a fraction due to congestion in large settlements. We use these scalings of emissions, along with a scaling related to urban form, to explain quantitatively how and why urban airshed-average air pollutant concentrations also scale with population. Our predicted concentration scaling with population is strongly sub-linear, with a slope about half that of the emissions scaling, consistent with satellite measurements of NO _2 columns over large cities across Europe. We demonstrate that the urban form of a particular settlement can result in the airshed-average air pollution of that settlement being much larger or smaller than expected. We extend our analysis to predict that the likelihood of occurrence of local air pollution hotspots will scale super-linearly with population, a testable hypothesis that awaits suitable data. Our analysis suggests that coordinated management of emissions and urban form would strongly reduce the likelihood of local pollutant hotspots occurring whilst also ameliorating the urban heat island effect under climate change. |
| first_indexed | 2024-03-12T15:57:39Z |
| format | Article |
| id | doaj.art-5f18147b31f648f2862ec6744d055bd0 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:57:39Z |
| publishDate | 2019-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-5f18147b31f648f2862ec6744d055bd02023-08-09T14:46:54ZengIOP PublishingEnvironmental Research Letters1748-93262019-01-01141212407810.1088/1748-9326/ab50e3Urban form strongly mediates the allometric scaling of airshed pollution concentrationsA R MacKenzie0https://orcid.org/0000-0002-8227-742XJ D Whyatt1https://orcid.org/0000-0001-9329-4367M J Barnes2G Davies3C N Hewitt4https://orcid.org/0000-0001-7973-2666School of Geography, Earth and Environmental Sciences, University of Birmingham , Birmingham B15 2TT, United Kingdom; Birmingham Institute of Forest Research, University of Birmingham , Birmingham, B15 2TT, United KingdomLancaster Environment Centre, Lancaster University , Lancaster LA1 4YQ, United KingdomLancaster Environment Centre, Lancaster University , Lancaster LA1 4YQ, United KingdomLancaster Environment Centre, Lancaster University , Lancaster LA1 4YQ, United KingdomLancaster Environment Centre, Lancaster University , Lancaster LA1 4YQ, United KingdomWe present allometric-scaling relationships between non-point-source emissions of air pollutants and settlement population, using 3030 urban settlements in Great Britain (home to ca. 80% of the population of that region). Sub-linear scalings (slope < 1.0; standard error on slope ∼0.01; r ^2 > 0.6) were found for the oxides of nitrogen (NO _x ) and microscopic airborne particles (PM _10 and PM _2.5 ). That is, emissions of these pollutants from larger cities are lower per capita than would be expected when compared to the same population dispersed in smaller settlements. The scalings of traffic-related emissions are disaggregated into a component due to under-use of roads in small settlements and a fraction due to congestion in large settlements. We use these scalings of emissions, along with a scaling related to urban form, to explain quantitatively how and why urban airshed-average air pollutant concentrations also scale with population. Our predicted concentration scaling with population is strongly sub-linear, with a slope about half that of the emissions scaling, consistent with satellite measurements of NO _2 columns over large cities across Europe. We demonstrate that the urban form of a particular settlement can result in the airshed-average air pollution of that settlement being much larger or smaller than expected. We extend our analysis to predict that the likelihood of occurrence of local air pollution hotspots will scale super-linearly with population, a testable hypothesis that awaits suitable data. Our analysis suggests that coordinated management of emissions and urban form would strongly reduce the likelihood of local pollutant hotspots occurring whilst also ameliorating the urban heat island effect under climate change.https://doi.org/10.1088/1748-9326/ab50e3urban air qualitynitrogen dioxideair pollutant emissionsair pollution managementurban planning |
| spellingShingle | A R MacKenzie J D Whyatt M J Barnes G Davies C N Hewitt Urban form strongly mediates the allometric scaling of airshed pollution concentrations Environmental Research Letters urban air quality nitrogen dioxide air pollutant emissions air pollution management urban planning |
| title | Urban form strongly mediates the allometric scaling of airshed pollution concentrations |
| title_full | Urban form strongly mediates the allometric scaling of airshed pollution concentrations |
| title_fullStr | Urban form strongly mediates the allometric scaling of airshed pollution concentrations |
| title_full_unstemmed | Urban form strongly mediates the allometric scaling of airshed pollution concentrations |
| title_short | Urban form strongly mediates the allometric scaling of airshed pollution concentrations |
| title_sort | urban form strongly mediates the allometric scaling of airshed pollution concentrations |
| topic | urban air quality nitrogen dioxide air pollutant emissions air pollution management urban planning |
| url | https://doi.org/10.1088/1748-9326/ab50e3 |
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