scholarly journals Urban Canyon in the CBD of Rio de Janeiro (Brazil): Thermal Profile of Avenida Rio Branco during Summer

Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Lidiane de Oliveira Lemos ◽  
Antonio Carlos Oscar Júnior ◽  
Francisco Mendonça

This study aims to evaluate the thermal field of the central business district (CBD) of Rio de Janeiro during summer from land surface temperature (LST) and the thermal characteristics of the urban canopy layer (UCL) of the urban canyon in Avenida Rio Branco. In order to conduct this evaluation, two methods were employed: (1) TIRS Landsat-8 sensor for data selection and processing (latest generation, 2011–2020); (2) a field survey using nine sampling points—seven along two mobile transects, one fixed point, and one vertical measurement point, which required the use of an RPA (remotely piloted aircraft). Three categories of analysis were established for the field survey based on the prevailing synoptic situations: stability, instability, and post-instability. The CBD is characterized by extensive areas with surface heat islands, in which temperatures were higher than 38.9 °C; the areas with milder LSTs were Campo do Santana, Avenida Rio Branco, and one of the mixed-use zones (Praça Mauá). With respect to Rio Branco Avenue, the LST niches of lowest elevation were derived through building shadowing; however, due to the nature of the data, the orbital data diverged from the observation data of the 10 field-study days. In situ data revealed that the characteristics urban morphology of Avenida Rio Branco, by contrast with the LST result, is susceptible to the formation of atmospheric heat islands, presenting heat islands of very strong magnitude (over 6.1 °C) in atmospheric stability, strong magnitude (4.1–6.0 °C) in atmospheric instability, and moderate magnitude (2.1–4.0 °C) in post-atmospheric instability. Despite the synoptic situation, thermal cores were concentrated at 1 p.m. The intersection between Avenida Rio Branco, Rua do Ouvidor, and Praça Mauá stored most of the solar energy received during the day due to the greater sky obstruction caused by the verticalization. Finally, vertical analysis demonstrated the formation of a thermal inversion on the night of the highest mean air temperature (29.5 °C), probably due to the roughness and number of buildings in the urban canyon.

Author(s):  
Lidiane de Oliveira Lemos ◽  
Antonio Carlos Oscar-Júnior ◽  
Francisco Mendonça

This study aims to evaluate the land surface temperature (LST) and the thermal characteristics of the Urban Canopy Layer (UCL) of the urban canyon in Avenida Rio Branco in the Central Business District (CBD) of Rio de Janeiro during summer. In order to conduct this evaluation, two methods were employed: 1) TIRS Landsat-8 sensor for data selection and processing (latest generation, 2011-2020); ; 2) field survey using nine sampling points — seven along two mobile transects, one fixed point, and one vertical measurement point, which required the use of a RPA (Remotely Piloted Aircraft). Three categories of analysis were established for the field survey based on the prevailing synoptic situations: stability, instability, and post-instability. The CBD is characterized by extensive areas with surface heat islands, in which temperatures were higher than 38.9°C; the areas with milder LSTs were Campo do Santana, Avenida Rio Branco, and one of the Mixed-Use Zones (Praça Mauá). With respect to Rio Branco Avenue, the LST niches of lowest elevation were derived through building shadowing; however, the orbital data diverged from the observation data of the ten field-study days. In situ data revealed that the characteristics urban morphology of Avenida Rio Branco is susceptible to the formation of heat islands, presenting heat islands of very strong magnitude (over 6.1°C) in atmospheric stability, strong magnitude (4.1-6.0°C) in atmospheric instability, and moderate magnitude (2.1°C-4.0°C) in post-atmospheric instability. Despite the synoptic situation, thermal cores were concentrated at 1 pm. The intersection between Avenida Rio Branco, Rua do Ouvidor, and Praça Mauá stored most of the solar energy received during the day due to the greater sky obstruction caused by the verticalization. Finally, vertical analysis demonstrated the formation of a thermal inversion on the night of the highest mean air temperature (29.5°C), probably, due to the roughness and number of buildings in the urban canyon.


Author(s):  
Lidiane de Oliveira Lemos ◽  
Antonio Carlos Oscar Júnior ◽  
Francisco Mendonça

This study aims to evaluate the land surface temperature (LST) and the thermal characteristics of the Urban Canopy Layer (UCL) of the urban canyon in Avenida Rio Branco in the Central Business District (CBD) of Rio de Janeiro during summer. In order to conduct this evaluation, two methods were employed: 1) summer LST estimation from the last decade (2011-2020); 2) field survey using nine sampling points — seven along two mobile transects, one fixed point, and one vertical measurement point, which required the use of a RPA (Remotely Piloted Aircraft). Three categories of analysis were established based on the prevailing synoptic situations: stability, instability, and post-instability. The CBD showed extensive areas with surface heat islands, in which temperatures were higher than 38.9°C; the areas with milder LSTs were Campo do Santana, Avenida Rio Branco, and one of the Mixed-Use Zones (Praça Mauá). The shadows of the buildings gave rise to niches of lower LSTs on Avenida Rio Branco; however, the satellite data and the data collected during the ten days of field experiments diverged. In situ data revealed that the urban morphology of Avenida Rio Branco is susceptible to the formation of heat islands, presenting heat islands of very strong magnitude (over 6.1°C) in atmospheric stability, strong magnitude (4.1-6.0°C) in atmospheric instability, and moderate magnitude (2.1°C-4.0°C) in post-atmospheric instability. Despite the synoptic situation, thermal cores were concentrated at 1 pm. The intersection between Avenida Rio Branco, Rua do Ouvidor, and Praça Mauá stored most of the solar energy received during the day. Finally, vertical analysis demonstrated the formation of a thermal inversion on the night of the highest mean air temperature (29.5°C), probably, due to the roughness and number of buildings in the urban canyon.


2020 ◽  
Vol 23 ◽  
Author(s):  
Emmanuela Lopes de Oliveira ◽  
Mara Telles Salles

Abstract Most cities have grown in a disorderly manner without planning or concern for the environment while urban infrastructure networks were emerging and being implemented. Furthermore, it is known that impacts on the environment such as increasing the soil-sealing rate favor increases in temperature and the formation of heat islands leading to climate change. Therefore, the study objective was to analyze the impacts of disorderly occupation of the urban subsoil by underground infrastructure networks on permeable areas and their relationship with climate change. The methodology was based on bibliographic research and a field survey. It was found that the greater the disorderly occupation of the urban subsoil, the smaller the areas destined as green and permeable areas and the greater the vulnerability to climate change.


2018 ◽  
Vol 10 (10) ◽  
pp. 1521 ◽  
Author(s):  
Yugang Tian ◽  
Hui Chen ◽  
Qingju Song ◽  
Kun Zheng

The distribution and dynamic changes in impervious surface areas (ISAs) are crucial to understanding urbanization and its impact on urban heat islands, earth surface energy balance, hydrological cycles, and biodiversity. Remotely sensed data play an essential role in ISA mapping, and numerous methods have been developed and successfully applied for ISA extraction. However, the heterogeneity of ISA spectra and the high similarity of the spectra between ISA and soil have not been effectively addressed. In this study, we selected data from the US Geological Survey (USGS) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) spectral libraries as samples and used blue and near-infrared bands as characteristic bands based on spectral analysis to propose a novel index, the perpendicular impervious surface index (PISI). Landsat 8 operational land imager data in four provincial capital cities of China (Wuhan, Shenyang, Guangzhou, and Xining) were selected as test data to examine the performance of the proposed PISI in four different environments. Threshold analysis results show that there is a significant positive correlation between PISI and the proportion of ISA, and threshold can be adjusted according to different needs with different accuracy. Furthermore, comparative analyses, which involved separability analysis and extraction precision analysis, were conducted among PISI, biophysical composition index (BCI), and normalized difference built-up index (NDBI). Results indicate that PISI is more accurate and has better separability for ISA and soil as well as ISA and vegetation in the ISA extraction than the BCI and NDBI under different conditions. The accuracy of PISI in the four cities is 94.13%, 96.50%, 89.51%, and 93.46% respectively, while BCI and NDBI showed accuracy of 77.53%, 93.49%, 78.02%, and 84.03% and 58.25%, 57.53%, 77.77%, and 64.83%, respectively. In general, the proposed PISI is a convenient index to extract ISA with higher accuracy and better separability for ISA and soil as well as ISA and vegetation. Meanwhile, as PISI only uses blue and near-infrared bands, it can be used in a wider variety of remote sensing images.


Author(s):  
Дмитрий Владимирович Сарычев ◽  
Ирина Владимировна Попова ◽  
Семен Александрович Куролап

Рассмотрены вопросы мониторинга теплового загрязнения окружающей среды в городах. Представлена методика отбора спектрозональных спутниковых снимков, их обработки и интерпретации полученных результатов. Для оценки городского острова тепла были использованы снимки с космического аппарата Landsat 8 TIRS. На их основе построены карты пространственной структуры острова тепла города Воронежа за летний и зимний периоды. Определены тепловые аномалии и выявлено 11 основных техногенных источников теплового загрязнения в г. Воронеже, установлена их принадлежность к промышленным зонам предприятий, а также к очистным гидротехническим сооружениям. Поверхностные температуры данных источников в среднем были выше фоновых температур приблизительно на 6° зимой и на 15,5° С летом. Синхронно со спутниковой съемкой были проведены наземные контрольные тепловизионные измерения температур основных подстилающих поверхностей в г. Воронеже. Полученные данные показали высокую сходимость космических и наземных измерений, на основании чего сделан вывод о надежности используемых данных дистанционного зондирования Земли в мониторинговых наблюдениях теплового загрязнения городской среды. Результаты работ могут найти применение в городском планировании и медицинской экологии. The study deals with the remote sensing and monitoring of urban heat islands. We present a methodology of multispectral satellite imagery selection and processing. The study bases on the freely available Landsat 8 TIRS data. We used multitemporal thermal band combinations to make maps of the urban heat island of Voronezh (Russia) during summer and winter periods. That let us identify 11 artificial sources of heat in Voronezh. All of them turned out to be allocated within industrial zones of plants and water treatment facilities. Land surface temperatures (LST) of these sources were approximately 6° and 15.5° C above the background temperatures in winter and summer, respectively. To prove the remotely sensed temperatures we conducted ground control measurements of LST of different surface types at the satellite revisit moments. Our results showed a significant correlation between the satellite and ground-based measurements, so the maps we produced in this study should be robust. They are of use in urban planning and medical ecology studies.


Author(s):  
Massimo Tadi ◽  
◽  
S. Vahabzadeh Manesh ◽  
Mohammad Hadi Mohammad Zadeh ◽  
Frederico Zaniol ◽  
...  

Author(s):  
T. Moss ◽  
B. Kar

Abstract. Urban expansion compounded by climate change appears to exacerbate the temperature difference between urban and rural areas. This temperature difference, known as the urban heat island (UHI) effect, results from lack of vegetation, increased impervious surfaces, excess heat released from human activities, and changing radiation and wind dynamics due to urban morphology. UHI has been found to increase heat-related illnesses, and in some instances, mortalities among vulnerable populations. Heat exposure is particularly pertinent in 2020, as stay-at-home orders and higher unemployment rates due to the COVID-19 pandemic have further exposed urban residents to local temperatures. Certain socio-economic groups that are more affected by COVID-19 are disproportionately exposed to high urban temperatures. We investigated the relationships between urban heat island intensity (UHII), normalized difference vegetation index (NDVI), and selected socio-economic factors for Dallas, TX and Phoenix, AZ for June 2020. We used an equal-weighting approach to combine socio-economic factors obtained from 2018 US Census Bureau data to determine socio-economic vulnerability, and used Landsat 8 imagery to derive NDVI and land surface temperature. Pearson’s correlation, hot spot analysis, and Moran’s I tests revealed that socio-economic vulnerability was higher in areas with high urban temperatures and decreased vegetation.


Author(s):  
A. Krtalić ◽  
A. Kuveždić Divjak ◽  
K. Čmrlec

Abstract. This study aims to assess surface urban heat islands (SUHIs) pattern over the city of Zagreb, Croatia, based on satellite (optical and thermal) remote sensing data. The spatio-temporal identification of SUHIs is analysed using the 12 sets of Landsat 8 imagery acquired during 2017 (in each month of the year). Vegetation cover within the city boundaries is extracted by using Principal Component Analysis (PCA) data fusion method on calculated three vegetation indices (VI): Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Ratio Vegetation Index (RVI) for each set of bands. The first principal component was used to compute the land surface temperature (LST) and deductive Environmental Criticality Index (ECI). As expected, the relationship between LST and all VI scores shows a negative correlation and is most negative with RVI. The environmentally critical areas and the patterns of seasonal variations of the SUHIs in the city of Zagreb were identified based on the LST, ECI and vegetation cover. The city centre, an industrial area in the eastern part and an area with shopping centers and commercial buildings in the western part of the city were identified as the most critical areas.


Author(s):  
C. A. Alcantara ◽  
J. D. Escoto ◽  
A. C. Blanco ◽  
A. B. Baloloy ◽  
J. A. Santos ◽  
...  

Abstract. Urbanization has played an important part in the development of the society, yet it is accompanied by environmental concerns including the increase of local temperature compared to its immediate surroundings. The latter is known as Urban Heat Islands (UHI). This research aims to model UHI in Quezon City based on Land Surface Temperature (LST) estimated from Landsat 8 data. Geospatial processing and analyses were performed using Google Earth Engine, ArcGIS, GeoDa, and SAGA GIS. Based on Urban Thermal Field Variance Index (UTFVI) and the normalized mean per barangay (village), areas with strong UHI intensities were mapped and characterized. high intensity UHIs are observed mostly in areas with high Normalized Difference Built-up Index (NDBI) like the residential regions while the weak intensity UHIs are noticed in areas with high Normalized Difference Vegetation Index (NDVI) near the La Mesa Reservoir. In the OLS regression model, around 69% of LST variability is explained by Surface Albedo (SA), Sky View Factor (SVF), Surface Area to Volume Ratio (SVR), Solar Radiation (SR), NDBI and NDVI. OLS yield relatively high residuals (RMSE = 1.67) and the residuals are not normally distributed. Since LST is non-stationary, Geographically Weighted Regression (GWR) regression was conducted, proving normally and randomly distributed residuals (average RMSE = 0.26).


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