scholarly journals Variação Microclimática de Sítios Urbanos com Diferentes Níveis de Cobertura Vegetal Como Subsídio à Formação de Ilha de Calor

2020 ◽  
Vol 13 (07) ◽  
pp. 3254
Author(s):  
Pedro Hugo Oliveira Moreira ◽  
Alan Cavalcanti da Cunha ◽  
João De Athaydes Silva Júnior ◽  
Antonio Carlos Lola da Costa
Keyword(s):  
Land Use ◽  
Relative Humidity ◽  
Urban Heat Island ◽  
Urban Space ◽  
Vegetation Index ◽  
Data Series ◽  
Heat Island ◽  
Urban Heat ◽  
Meteorological Elements ◽  
The City

O objetivo da investigação é analisar variações espaciais e sazonais de elementos meteorológicos que evidenciam a formação e ocorrência do fenômeno da Ilha de Calor Urbana (ICU) na cidade de Macapá. A metodologia de estudo avaliou a evolução histórica da cobertura de vegetação e da malha urbana utilizando-se técnicas de geoprocessamento e de classificação supervisionada de Máxima Verossimilhança (MAXVER). Com este objetivo foram analisadas séries de dados contínuos coletados durante dez dias consecutivos nos períodos chuvoso (Abril/2018), Seco (Novembro/2018) e Transição (Junho/2019). Os elementos meteorológicos quantificados foram a umidade relativa do ar (UR) e a temperatura média do ar (T). Cinco estações semi-automáticas foram estrategicamente distribuídas ao longo de dois eixos de máximo prolongamento da zona urbana de Macapá, nos sentidos Nordeste-Sudoeste e Oeste-Leste. Os resultados indicaram significativa variação sazonal da Temperatura e da Umidade Relativa (p<0,05). Espacialmente, os resultados também foram significativos (p<0,05), sugerindo influência espaço-sazonal dos padrões de variabilidade de T e UR sobre ICU correlacionados com as taxas de uso e ocupação do solo. Assim, ICU mostrou-se significativamente dependente tanto do índice de vegetação (R2=0,47, p<0,05) quanto do índice de urbanização (R2=0,62, p<0,05). Conclui-se que a sazonalidade diária observada sugere existência do fenômeno da ilha de calor urbana, especialmente nas zonas central e sul da cidade, cujos índices inclusive têm sido confirmados por estudos similares. Os dados de sazonalidade dos elementos meteorológicos analisados, sua relação com o uso do solo, podem trazer elementos importantes para o debate sobre a formação da ICU nas cidades amazônicas. Microclimatic Variation in Urban Sites with Different Levels of Vegetable Cover as a Subsidy to the Formation of Heat Island A B S T R A C TThe objective of the investigation is to analyze spatial and seasonal variations of meteorological elements that evidence the formation and occurrence of the phenomenon of the Urban Heat Island (UHI) in the city of Macapá. The study methodology comprised the historical evolution of vegetation cover and urban space using geoprocessing techniques and supervised classification of Maximum Likelihood (MAXVER). With this objective, continuous data series collected during ten consecutive days in the rainy (April/2018), Dry (November/2018) and Intermediate (June/2019) periods were analyzed. The meteorological elements quantified were relative humidity (RH) and average air temperature (T). Five semi-automatic gauges were strategically distributed along two axes of maximum extension of the urban area of Macapá, in the Northeast-Southwest and West-East directions. The results indicated significant seasonal variation of Temperature and Relative Humidity (p<0.05). Spatially, the results were also significant (p<0.05), suggesting influence of T and RH variability patterns on UHI correlated with land use and occupation rates on. Thus, ICU was significantly dependent on both the vegetation index (R2=0.47, p<0.05) and the urbanization index (R2=0.62, p<0.05). We concluded that the daily seasonality observed suggests the existence of the phenomenon of the urban heat island, especially in the central and southern zones of the city, whose indices have even been confirmed by similar studies. The seasonality data of the meteorological elements analyzed, their relationship with land use, can bring important elements to the debate on the formation of ICU in Amazonian cities.Keywords: Meteorological element, vegetation, urbanization, urban heat island, Macapá.

scholarly journals MONITORING SPATIOTEMPORAL CHANGES OF HEAT ISLAND IN BABOL CITY DUE TO LAND USE CHANGES

2017 ◽  
Vol XLII-4/W4 ◽  
pp. 17-22 ◽  
Author(s):  
S. K. Alavi Panah ◽  
M. Kiavarz Mogaddam ◽  
M. Karimi Firozjaei
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Urban Heat Island ◽  
Land Surface ◽  
Land Use Changes ◽  
Heat Island ◽  
Time Period ◽  
Urban Heat ◽  
The City ◽  
Very High

Urban heat island is one of the most vital environmental risks in urban areas. The advent of remote sensing technology provides better visibility due to the integrated view, low-cost, fast and effective way to study and monitor environmental and humanistic changes. The aim of this study is a spatiotemporal evaluation of land use changes and the heat island in the time period of 1985-2015 for the studied area in the city of Babol. For this purpose, multi-temporal Landsat images were used in this study. For calculating the land surface temperature (LST), single-channel and maximum likelihood algorithms were used, to classify Images. Therefore, land use changes and LST were examined, and thereby the relationship between land-use changes was analyzed with the normalized LST. By using the average and standard deviation of normalized thermal images, the area was divided into five temperature categories, inter alia, very low, low, medium, high and very high and then, the heat island changes in the studied time period were investigated. The results indicate that land use changes for built-up lands increased by 92%, and a noticeable decrease was observed for agricultural lands. The Built-up land changes trend has direct relation with the trend of normalized surface temperature changes. Low and very low-temperature categories which follow a decreasing trend, are related to lands far away from the city. Also, high and very high-temperature categories whose areas increase annually, are adjacent to the city center and exit ways of the town. The results emphasize on the importance of attention of urban planners and managers to the urban heat island as an environmental risk.

scholarly journals Analysis of the urban heat island in representative points of the city of Bayeux / PB

2018 ◽  
Vol 7 (6) ◽  
pp. 345
Author(s):  
Amanda Mayara Paulino Da Silva
Keyword(s):  
Land Use ◽  
Urban Heat Island ◽  
Thermal Field ◽  
Urban Climate ◽  
Urban Heat Islands ◽  
Heat Island ◽  
Thermal Discomfort ◽  
Heat Islands ◽  
Urban Heat ◽  
The City

Abstrat Urban growth has generated several socio-environmental problems and has altered the quality of life of people living in these environments. Due to the disorderly growth of cities and the various forms of urban land use and occupation, changes in the thermal field of these areas have occurred and caused the formation of urban heat islands and thermal discomfort in urban environments. Thus, the need to understand the formation of heat islands in these areas and the study of their causes and consequences grows. Given this context, the present work intends to study the urban climate of the city of Bayeux / PB, specifically the urban thermal field, and the formation of heat islands. For the accomplishment of the research, initially a bibliographical survey of the subject in question was made. Subsequently experimental points of meteorological data collection (temperature and relative air humidity) were defined in the metropolitan area of the city of João Pessoa, specifically in the municipality of Bayeux / PB. These points were defined based on the different types of land use and cover in the study area. The following experimental points were defined: a point in the center of the city of Bayeux / PB, another point on the banks of the BR230 direction Bayeux, and a reference point in a remnant of Atlantic forest. To obtain the urban heat island the reference point was used as a parameter of the climatic conditions of a natural environment. The data of temperature and relative humidity were collected through thermometers (HOBO U-10), which were placed on steel tripods (1.5 meters high) and monitored at uninterrupted intervals of 1 and 1 hour during the dry period and rainy region. The analysis of the data points to the formation of urban heat islands in the two periods evaluated in the city of Bayeux / PB, being the center of the city, the most critical area with the most intense heat islands. The vegetative cover played a predominant role in the climatic mitigation of the experimental samples as well as the presence of precipitation. The areas with impermeable soil cover presented the largest heat islands and contributed to the thermal discomfort of the study area. Keywords: Urban Climate, Thermodynamic Field, Urban Heat Island.

Measurement and Statistical Modeling of the Urban Heat Island of the City of Utrecht (the Netherlands)

2012 ◽  
Vol 51 (6) ◽  
pp. 1046-1060 ◽  
Author(s):  
Theo Brandsma ◽  
Dirk Wolters
Keyword(s):  
Land Use ◽  
Wind Speed ◽  
The Netherlands ◽  
Urban Heat Island ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Urban Heat ◽  
The Mean ◽  
View Factors ◽  
The City

AbstractMobile temperature and humidity measurements have been performed along a 14-km transect through the city of Utrecht, in the Netherlands (311 000 inhabitants), during the period March 2006–January 2009. The measurements took place on a bicycle during commuter traffic and resulted in 106 nighttime profiles (before sunrise) and 77 daytime (afternoon) profiles. It is shown how the intensity of the urban heat island depends on wind direction, cloudiness, and wind speed. Statistical models are constructed that relate the mean and maximum nighttime urban heat island intensity profiles to area-averaged sky-view factors and land use combined at both the micro- and local scales. Sky-view factors are estimated from a 0.5 m × 0.5 m surface elevation database, and land use is obtained from a 25 m × 25 m land-use database. The models are calibrated using the mobile measurements and provide estimates of the spatial distribution of the mean and maximum nighttime urban heat island intensity in Utrecht. Both models explain more than 75% of the variance. A separate nonlinear model is introduced that relates the temperature differences between the warmest part and coolest part of the transects to wind speed and cloudiness.

scholarly journals Urban "Heat-Island Effect" and its Connection with Architectural and Climatic Features on the Example of Poltava

2018 ◽  
Vol 7 (3.2) ◽  
pp. 597
Author(s):  
Yuri Golik ◽  
Oksana Illiash ◽  
Nataliia Maksiuta
Keyword(s):  
Urban Heat Island ◽  
Traditional Method ◽  
Urban Heat Island Effect ◽  
Heat Island ◽  
Island Effect ◽  
Temperature Regimes ◽  
Architectural Features ◽  
Urban Heat ◽  
The Given ◽  
The City

The concept of "heat-island effect", its structure and features of formation over the city are given. The climatic and other features of the city that influence the formation of this phenomenon are mentioned.  The data on functioning in the city of the municipal production enterprise of the heat economy is indicated. The traditional method for determining the formation of the urban "heat-island effect" is described. The data and comparative graphs on the temperature regimes of the city and region are presented. The possibility of influencing architectural features of the city on the formation of the "heat-island-effect" is determined. According to the obtained results, further integrated researches are proposed for obtaining reliable results of the given question. 

scholarly journals RELATIONSHIPS BETWEEN LAND USE/LAND COVER AND LAND SURFACE TEMPERATURE IN TABRIZ FROM 2000 TO 2017

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 1041-1044
Author(s):  
A. Tahooni ◽  
A. A. Kakroodi
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Urban Heat Island ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Impervious Surface ◽  
Bare Soil ◽  
Heat Island ◽  
Land Use Land Cover ◽  
Urban Heat

Abstract. Urban Heat Island (UHI) refers to the development of higher urban temperatures of an urban area compared to the temperatures of surrounding suburban and rural areas. Highly reflective urban materials to solar radiation present a significantly lower surface temperature and contribute to reducing the sensible heat released in the atmosphere and mitigating the urban heat island. Many studies of the UHI effect have been based on Land Surface Temperature (LST) measurements from remote sensors. The remotely sensed UHI has been termed the surface urban heat island (SUHI) effect. This study examines Tabriz city land use/land cover (LULC) and LST changes using Landsat satellite images between 2000 and 2017. Maximum likelihood classification and single channel methods were used for LULC classification and LST retrieval respectively. Results show that impervious surface has increased 13.79% and bare soil area has decreased 16.2%. The results also revealed bare soil class LST after a constant trend become increasing. It also revealed the impervious surface LST has a decreasing trend between 2000 and 2011 and has a little change. Using materials that have low absorption and high reflectance decrease the effect of heat island considerably.

scholarly journals A High-Resolution Monitoring Approach of Canopy Urban Heat Island using Random Forest Model and Multi-platform Observations

2021 ◽  
Author(s):  
Shihan Chen ◽  
Yuanjian Yang ◽  
Fei Deng ◽  
Yanhao Zhang ◽  
Duanyang Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Random Forest ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Model Framework ◽  
Rapid Urbanization ◽  
Urban Heat ◽  
The City

Abstract. Due to rapid urbanization and intense human activities, the urban heat island (UHI) effect has become a more concerning climatic and environmental issue. A high spatial resolution canopy UHI monitoring method would help better understand the urban thermal environment. Taking the city of Nanjing in China as an example, we propose a method for evaluating canopy UHI intensity (CUHII) at high resolution by using remote sensing data and machine learning with a Random Forest (RF) model. Firstly, the observed environmental parameters [e.g., surface albedo, land use/land cover, impervious surface, and anthropogenic heat flux (AHF)] around densely distributed meteorological stations were extracted from satellite images. These parameters were used as independent variables to construct an RF model for predicting air temperature. The correlation coefficient between the predicted and observed air temperature in the test set was 0.73, and the average root-mean-square error was 0.72 °C. Then, the spatial distribution of CUHII was evaluated at 30-m resolution based on the output of the RF model. We found that wind speed was negatively correlated with CUHII, and wind direction was strongly correlated with the CUHII offset direction. The CUHII reduced with the distance to the city center, due to the de-creasing proportion of built-up areas and reduced AHF in the same direction. The RF model framework developed for real-time monitoring and assessment of high-resolution CUHII provides scientific support for studying the changes and causes of CUHII, as well as the spatial pattern of urban thermal environments.

scholarly journals Solar Irradiance Reduction Using Optimized Green Infrastructure in Arid Hot Regions: A Case Study in El-Nozha District, Cairo, Egypt

2021 ◽  
Vol 13 (17) ◽  
pp. 9617 ◽  
Author(s):  
Wesam M. Elbardisy ◽  
Mohamed A. Salheen ◽  
Mohammed Fahmy
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Green Infrastructure ◽  
Solar Irradiance ◽  
Urban Trees ◽  
Heat Island ◽  
Physiological Equivalent Temperature ◽  
Urban Climatology ◽  
Urban Heat ◽  
The City

In the Middle East and North Africa (MENA) region, studies focused on the relationship between urban planning practice and climatology are still lacking, despite the fact that the latter has nearly three decades of literature in the region and the former has much more. However, such an unfounded relationship that would consider urban sustainability measures is a serious challenge, especially considering the effects of climate change. The Greater Cairo Region (GCR) has recently witnessed numerous serious urban vehicular network re-development, leaving the city less green and in need of strategically re-thinking the plan regarding, and the role of, green infrastructure. Therefore, this study focuses on approaches to the optimization of the urban green infrastructure, in order to reduce solar irradiance in the city and, thus, its effects on the urban climatology. This is carried out by studying one of the East Cairo neighborhoods, named El-Nozha district, as a representative case of the most impacted neighborhoods. In an attempt to quantify these effects, using parametric simulation, the Air Temperature (Ta), Mean Radiant Temperature (Tmrt), Relative Humidity (RH), and Physiological Equivalent Temperature (PET) parameters were calculated before and after introducing urban trees, acting as green infrastructure types that mitigate climate change and the Urban Heat Island (UHI) effect. Our results indicate that an optimized percentage, spacing, location, and arrangement of urban tree canopies can reduce the irradiance flux at the ground surface, having positive implications in terms of mitigating the urban heat island effect.

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