scholarly journals Developing Vulnerability Index to Quantify Urban Heat Islands Effects Coupled with Air Pollution: A Case Study of Camden, NJ

2020 ◽  
Vol 9 (6) ◽  
pp. 349 ◽  
Author(s):  
Samain Sabrin ◽  
Maryam Karimi ◽  
Rouzbeh Nazari

Extreme heat events at urban centers in combination with air pollution pose a serious risk to human health. Among these are financially distressed cities and neighborhoods that are facing enormous challenges without the scientific and technical capacity for planning and mitigation. The city of Camden is one of those economically distressed areas with a predominantly minority population, a high unemployment rate, high poverty rates, and poor air quality (PM2.5 and ozone), and it remains vulnerable to heat events. This paper focuses on studying a coupled effect of Urban Heat Islands (UHIs) and Ozone-PM2.5 pollution at the neighborhood-scale in the city of Camden, using fine scale remotely sensed land-surface temperature and air quality data from the Community Multiscale Air Quality (CMAQ) Modelling System in the Geographic Information Systems (GIS) platform. To assess the impact of urban microclimate on the city of Camden, NJ, residents’ health, we identified several environmental and social parameters as the root causes of vulnerability imposed by extreme-heat and poor air quality. Vulnerability in terms of environment and social wellbeing was spatially quantified as two conceptual vulnerability-index models (i.e., environmental vulnerability index (EVI) and a social vulnerability index (SVI)) using multiple linear regression algorithm. Factors such as remotely sensed earth surface properties, built-environment components, air quality, and socio-economic data were incorporated in a holistic geographic approach to quantify the combined effect. Surface temperature gradient and Proportional Vegetation (Pv) generated from 30 m resolution Landsat 8 were sampled along with other variables in the city of Camden, NJ. Models incorporating Pv suggest better fit than models with normalized difference vegetation index (NDVI). Water fraction (33.5%, 32.4%), percentage imperviousness (32.5%, 32%), Pv (20.5%, 19.6%), and digital elevation model (DEM) (9%, 8%) have the highest contributions in both models. Two output maps identified the vulnerable neighborhoods in the city through comprehensive GIS analysis: Lanning Square, Bergen Square, Central Waterfront, Gateway, Liberty Park, and Parkside. This can provide useful information for planners and health officials in targeting areas for future interventions and mitigations.

2019 ◽  
Vol 11 (12) ◽  
pp. 1449 ◽  
Author(s):  
Carlos Granero-Belinchon ◽  
Aurelie Michel ◽  
Jean-Pierre Lagouarde ◽  
Jose A. Sobrino ◽  
Xavier Briottet

Urban Heat Islands (UHIs) at the surface and canopy levels are major issues in urban planification and development. For this reason, the comprehension and quantification of the influence that the different land-uses/land-covers have on UHIs is of particular importance. In order to perform a detailed thermal characterisation of the city, measures covering the whole scenario (city and surroundings) and with a recurrent revisit are needed. In addition, a resolution of tens of meters is needed to characterise the urban heterogeneities. Spaceborne remote sensing meets the first and the second requirements but the Land Surface Temperature (LST) resolutions remain too rough compared to the urban object scale. Thermal unmixing techniques have been developed in recent years, allowing LST images during day at the desired scales. However, while LST gives information of surface urban heat islands (SUHIs), canopy UHIs and SUHIs are more correlated during the night, hence the development of thermal unmixing methods for night LSTs is necessary. This article proposes to adapt four empirical unmixing methods of the literature, Disaggregation of radiometric surface Temperature (DisTrad), High-resolution Urban Thermal Sharpener (HUTS), Area-To-Point Regression Kriging (ATPRK), and Adaptive Area-To-Point Regression Kriging (AATPRK), to unmix night LSTs. These methods are based on given relationships between LST and reflective indices, and on invariance hypotheses of these relationships across resolutions. Then, a comparative study of the performances of the different techniques is carried out on TRISHNA synthesized images of Madrid. Since TRISHNA is a mission in preparation, the synthesis of the images has been done according to the planned specification of the satellite and from initial Aircraft Hyperspectral Scanner (AHS) data of the city obtained during the DESIREX 2008 capaign. Thus, the coarse initial resolution is 60 m and the finer post-unmixing one is 20 m. In this article, we show that: (1) AATPRK is the most performant unmixing technique when applied on night LST, with the other three techniques being undesirable for night applications at TRISHNA resolutions. This can be explained by the local application of AATPRK. (2) ATPRK and DisTrad do not improve significantly the LST image resolution. (3) HUTS, which depends on albedo measures, misestimates the LST, leading to the worst temperature unmixing. (4) The two main factors explaining the obtained performances are the local/global application of the method and the reflective indices used in the LST-index relationship.


Author(s):  
E. N. Sutyrina ◽  

The investigation is aimed to determine the boundaries and intensity of urban heat islands in the Irkutsk region and assess the change in these parameters over a long-term period. The formation of an urban heat island is an example of anthropogenic influence on the urban climate. Land surface temperature and its spatial and temporal variations can be used to study urban heat islands, since the difference between the land surface temperature within the city and its surroundings is the result of the transformation of the underlying surface, heat capacity and three-dimensional structure of urban buildings in the process of urbanization. In order to study the phenomenon of urban heat islands of cities of the Irkutsk region, the land surface temperature data reconstructed from AVHRR-based thermal infrared imagery for 1998-2019 was used. As a result of the study, multi-temporal maps showing the urban heat islands of the agglomeration of Irkutsk-Angarsk-Shelekhov and the city of Bratsk were obtained. The investigated heat islands are characterized by a significant diurnal dynamic, so the difference in temperature values between the city and the suburbs in summer daytime reached 8-10 °C, in the evening and at night in summer this parameter decreases to 3-5 °C. The dimensions of the urban heat islands of the cities under investigation in the daytime exceed the dimensions of these heat anomalies in the evening and at night. Interannual variability in the intensity of urban heat islands did not show statistically significant trends from 1998 to 2019, the areas of urban heat islands increased significantly over the study period. The observed increase in area was probably associated with the development of the cities under study, with the transformation of landscapes and a decrease in the density of vegetation in the suburbs. In order to assess the contribution of the lack of vegetation to the formation of the urban heat islands in summer daytime, the values of the land surface temperature were compared with the values of the vegetation index NDVI. An analysis of the relationships between these parameters found that daytime land surface temperature was in close inverse relationship with the NDVI value, while this relationship was less pronounced at night and in the evening.


Author(s):  
Simil Amir Siddiqui

Urban heat islands (UHI) are areas with elevated temperatures occurring in cities compared to surrounding rural areas. This study realizes the lack of research regarding the trends of UHIs in desert countries and focuses on Doha. The research includes twelve months of two-time periods; 2000-2019. ArcGIS software was used to compute the land surface temperature (LST) of the city using Landsat images. Land use/land cover (LULC) maps were computed to show how the city has evolved in 19 years. 30 field samples were used to verify the accuracy of the LULC. Results showed UHI in Doha did not display similar pattern to that of cities in subtropical and temperate regions. Higher temperatures were prevalent in out-skirts comprising of barren and built-up areas with high population and no vegetation. Comparatively, the main downtown with artificially planted vegetation and shade from skyscrapers created cooler microclimates. The overall LST of greater Doha has increased by 0.7°C from 2000 to 2019. Furthermore %LULC of built up, vegetation, barren land, marsh land and water body were 29%, 4.5%, 58.6%, 2.8% and 5% in 2000 and 56.5 %, 8.2%, 33.2 %, 0% and 2.1% in 2019 respectively. Overall, there was an increase in built-up and vegetation decrease in water and barren areas and complete loss of marshland. Highest temperatures were recorded for marshland area in year 2000 and barren and built in year 2019. Transect profiles showed positive correlation between NDBI and LST and a negative correlation between NDVI and LST.


Author(s):  
Boubaker Khallef ◽  
Yamina Biskri ◽  
Nabil Mouchara ◽  
Khaled Brahamia

This study aims to analyze the urban heat islands of the city of Guelma using Landsat 8 data and the geographic information system. The application of the single Chanel algorithm has been applied to extract surface temperature (LST) from Landsat 8 data. The result obtained shows that the surface temperature of August 11, 2019 in the city of Guelma varied from 36 to 47 degrees. However, the correlation between the LST, the NDVI and the NDBI allowed characterizing the effects of the green zones and the water resources thus the grounds built on the urban heat islands. The ecological assessment was performed using an urban thermal field variance index (UTFVI). The result obtained from this ecological assessment shows that 4 km2 of the surface of the city of Guelma represents a much worse ecological quality. It is therefore urgent for this city to strengthen and expand the strategies for reducing the effects of urban heat islands for preserve the quality of urban life of the inhabitants.


2021 ◽  
Vol 70 ◽  
pp. 1-14
Author(s):  
Mohamed Anis Fekih ◽  
Walid Bechkit ◽  
Herve Rivano ◽  
Manoel Dahan ◽  
Florent Renard ◽  
...  

2020 ◽  
Vol 12 (23) ◽  
pp. 10089
Author(s):  
Andre M. Eanes ◽  
Todd R. Lookingbill ◽  
Jeremy S. Hoffman ◽  
Kelly C. Saverino ◽  
Stephen S. Fong

Air pollution and the urban heat island effect are consistently linked to numerous respiratory and heat-related illnesses. Additionally, these stressors disproportionately impact low-income and historically marginalized communities due to their proximity to emissions sources, lack of access to green space, and exposure to other adverse environmental conditions. Here, we use relatively low-cost stationary sensors to analyze PM2.5 and temperature data throughout the city of Richmond, Virginia, on the ten hottest days of 2019. For both hourly means within the ten hottest days of 2019 and daily means for the entire record for the year, the temperature was found to exhibit a positive correlation with PM2.5. Analysis of hourly means on the ten hottest days yielded a diurnal pattern in which PM2.5 levels peaked in the early morning and reached their minima in the mid-afternoon. Spatially, sites exhibiting higher temperatures consistently had higher PM2.5 readings, with vulnerable communities in the east end and more intensely developed parts of the city experiencing significantly higher temperatures and PM2.5 concentrations than the suburban neighborhoods in the west end. These findings suggest an uneven distribution of air pollution in Richmond during extreme heat events that are similar in pattern but less pronounced than the temperature differences during these events, although further investigation is required to verify the extent of this relationship. As other studies have found both of these environmental stressors to correlate with the distribution of green space and other land-use factors in cities, innovative and sustainable planning decisions are crucial to the mitigation of these issues of inequity going forward.


Author(s):  
Pieter Snyman ◽  
A. Stephen Steyn

Urban heat islands (UHIs) are characterised by warmer urban air temperatures compared to rural air temperatures, and the intensity is equal to the difference between the two. Air temperatures are measured at various sites across the city of Bloemfontein and then analysed to determine the UHI characteristics. The UHI is found to have a horseshoe shape and reaches a maximum intensity of 8.2 °C at 22:00. The UHI is largely affected by the local topography.


1978 ◽  
Vol 9 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Lawrence C. Nkemdirim ◽  
Keith Leggat

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