scholarly journals The basic characteristics of the Belgrade’s heat island

2003 ◽  
Vol 83 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Goran Andjelkovic
Keyword(s):  
Air Temperature ◽  
Space Structure ◽  
Absolute Temperature ◽  
Heat Island ◽  
Temperature Minimum ◽  
City Center ◽  
Climatic Period ◽  
Average Annual Temperature ◽  
The Absolute ◽  
The City

The urban heat island, as a phenomenon due to the higher air temperature in the cities as compared to their immediate surroundings, represents the most important consequence of the urbanization influence on the topoclimate. As compared to the smaller cities in its surroundings, Belgrade's average annual temperature is from 0,4 to 1,0 ?C higher (period 1961-1990). A very liable index of the Belgrade's heat island is the air temperature measured at the airport in Surcin. In the period from 1971-1990. average annual air temperature at the airport was 11,2 ?C, and in the city center it was 0,7 ?C higher. Belgrade has a higher absolute minimal temperature than its surroundings during every month. In the last climatic period the absolute temperature minimum in Belgrade was even 5,4 ?C higher than the highest value measured within this parameter in its wider surroundings (Veliko Gradiste -26,4 ?C). In the above mentioned twenty years period the absolute air temperature minimum in Surcin was -26,0 ?C, and in the city center only -18,2 ?C. The number of the frosty days at the airport was 77,8, and in Belgrade 58,2. Although the heat island of Belgrade was formed together with formation of the city, it was more evident at the beginning of the 20th century (0,4 ?C). During the next five to six decades a faster intensity growth was recorded (up to 0,9 ?C). This coincides with the period of the population growth as well as with development of the city activities, industry above all. During one year the intensity of the Belgrade's heat island reached its maximum in winter. In January the city, as compared to Surcin, was warmer for about 1,0 ?C, and in September for only 0,1 ?C. The daily variations of the heat island are such that it reaches its highest intensity during the evening hours (at 9 p.m. 0,9 ?C). If the average values of the extreme daily temperatures are being examined, one can see a distinct difference: average city minimums are 1,5 ?C higher than the airport minimums, while the maximums are only 0,2 ?C higher. During winter, in concrete anticyclonic conditions, it can be 10 ?C warmer in the city than in the immediate surroundings. Together with the perennial growth of heat island intensity, its "space range" also expands. The space structure of the heat island is very distinct. Exceptions in the temperature values between certain points of measurements in the winter morning hours can go up to 6-8 ?C.

scholarly journals Analysis of climate change in Dnipropetrovsk Region

2017 ◽  
pp. 43-51
Author(s):  
V. V. Hrynchak
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Climate Changes ◽  
Absolute Temperature ◽  
Climatic Conditions ◽  
Annual Precipitation ◽  
Temperature And Precipitation ◽  
Weather Observations ◽  
Average Annual Temperature

The decision about writing this article was made after familiarization with the "Brief Climatic Essay of Dnepropetrovsk City (prepared based on observations of 1886 – 1937)" written by the Head of the Dnipropetrovsk Weather Department of the Hydrometeorological Service A. N. Mikhailov. The guide has a very interesting fate: in 1943 it was taken by the Nazis from Dnipropetrovsk and in 1948 it returned from Berlin back to the Ukrainian Hydrometeorological and Environmental Directorate of the USSR, as evidenced by a respective entry on the Essay's second page. Having these invaluable materials and data of long-term weather observations in Dnipro city we decided to analyze climate changes in Dnipropetrovsk region. The article presents two 50-year periods, 1886-1937 and 1961-2015, as examples. Series of observations have a uniform and representative character because they were conducted using the same methodology and results processing. We compared two main characteristics of climate: air temperature and precipitation. The article describes changes of average annual temperature values and absolute temperature values. It specifies the shift of seasons' dates and change of seasons' duration. We studied the changes of annual precipitation and peculiarities of their seasonable distribution. Apart from that peculiarities of monthly rainfall fluctuations and their heterogeneity were specified. Since Dnipro city is located in the center of the region the identified tendencies mainly reflect changes of climatic conditions within the entire Dnipropetrovsk region.

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 Assessment of Changes in Land Use/Land Cover and Land Surface Temperatures and Their Impact on Surface Urban Heat Island Phenomena in the Kathmandu Valley (1988–2018)

2020 ◽  
Vol 9 (12) ◽  
pp. 726
Author(s):  
Md. Omar Sarif ◽  
Bhagawat Rimal ◽  
Nigel E. Stork
Keyword(s):  
Urban Heat Island ◽  
Land Surface ◽  
Agricultural Land ◽  
Kathmandu Valley ◽  
Heat Island ◽  
City Center ◽  
Urban Heat ◽  
Surface Urban Heat Island ◽  
The City ◽  
Normal Difference

More than half of the world’s populations now live in rapidly expanding urban and its surrounding areas. The consequences for Land Use/Land Cover (LULC) dynamics and Surface Urban Heat Island (SUHI) phenomena are poorly understood for many new cities. We explore this issue and their inter-relationship in the Kathmandu Valley, an area of roughly 694 km2, at decadal intervals using April (summer) Landsat images of 1988, 1998, 2008, and 2018. LULC assessment was made using the Support Vector Machine algorithm. In the Kathmandu Valley, most land is either natural vegetation or agricultural land but in the study period there was a rapid expansion of impervious surfaces in urban areas. Impervious surfaces (IL) grew by 113.44 km2 (16.34% of total area), natural vegetation (VL) by 6.07 km2 (0.87% of total area), resulting in the loss of 118.29 km2 area from agricultural land (17.03% of total area) during 1988–2018. At the same time, the average land surface temperature (LST) increased by nearly 5–7 °C in the city and nearly 3–5 °C at the city boundary. For different LULC classes, the highest mean LST increase during 1988–2018 was 7.11 °C for IL with the lowest being 3.18 °C for VL although there were some fluctuations during this time period. While open land only occupies a small proportion of the landscape, it usually had higher mean LST than all other LULC classes. There was a negative relationship both between LST and Normal Difference Vegetation Index (NDVI) and LST and Normal Difference Moisture Index (NDMI), respectively, and a positive relationship between LST and Normal Difference Built-up Index (NDBI). The result of an urban–rural gradient analysis showed there was sharp decrease of mean LST from the city center outwards to about 15 kms because the NDVI also sharply increased, especially in 2008 and 2018, which clearly shows a surface urban heat island effect. Further from the city center, around 20–25 kms, mean LST increased due to increased agriculture activity. The population of Kathmandu Valley was 2.88 million in 2016 and if the growth trend continues then it is predicted to reach 3.85 million by 2035. Consequently, to avoid the critical effects of increasing SUHI in Kathmandu it is essential to improve urban planning including the implementation of green city technologies.

scholarly journals Changes in the Water Temperature of Rivers Impacted by the Urban Heat Island: Case Study of Suceava City

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1343 ◽  
Author(s):  
Andrei-Emil Briciu ◽  
Dumitru Mihăilă ◽  
Adrian Graur ◽  
Dinu Iulian Oprea ◽  
Alin Prisăcariu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Urban Heat Island ◽  
River Water ◽  
Air Temperature ◽  
Stream Water ◽  
Heat Island ◽  
Urban Heat ◽  
The City ◽  
River Water Temperature

Cities alter the thermal regime of urban rivers in very variable ways which are not yet deciphered for the territory of Romania. The urban heat island of Suceava city was measured in 2019 and its impact on Suceava River was assessed using hourly and daily values from a network of 12 water and air monitoring stations. In 2019, Suceava River water temperature was 11.54 °C upstream of Suceava city (Mihoveni) and 11.97 °C downstream (Tişăuţi)—a 3.7% increase in the water temperature downstream. After the stream water passes through the city, the diurnal thermal profile of Suceava River water temperature shows steeper slopes and earlier moments of the maximum and minimum temperatures than upstream because of the urban heat island. In an average day, an increase of water temperature with a maximum of 0.99 °C occurred downstream, partly explained by the 2.46 °C corresponding difference between the urban floodplain and the surrounding area. The stream water diurnal cycle has been shifted towards a variation specific to that of the local air temperature. The heat exchange between Suceava River and Suceava city is bidirectional. The stream water diurnal thermal cycle is statistically more significant downstream due to the heat transfer from the city into the river. This transfer occurs partly through urban tributaries which are 1.94 °C warmer than Suceava River upstream of Suceava city. The wavelet coherence analyses and ANCOVA (analysis of covariance) prove that there are significant (0.95 confidence level) causal relationships between the changes in Suceava River water temperature downstream and the fluctuations of the urban air temperature. The complex bidirectional heat transfer and the changes in the diurnal thermal profiles are important to be analysed in other urban systems in order to decipher in more detail the observed causal relationships.

scholarly journals The urban heat island and the features of the flora in the Lublin City area, SE Poland

2018 ◽  
Vol 71 (2) ◽  
Author(s):  
Anna Rysiak ◽  
Bożenna Czarnecka
Keyword(s):  
Species Richness ◽  
Urban Heat Island ◽  
Thermal Conditions ◽  
Life Forms ◽  
Ecological Indicator ◽  
Heat Island ◽  
City Center ◽  
Suburban Areas ◽  
Urban Heat ◽  
The City

Various forms of human activity in large cities contribute to the creation of a specific climate and new environmental conditions for plants. One of the most important results is the so-called atmospheric urban heat island (UHI). The aim of this study was to compare the thermal conditions in the Lublin City center with those of suburban areas, and so confirm the existence of the UHI and then analyze the influence of thermal conditions on features of the flora. The analysis of the air temperatures was based on data from 2000 to 2014 provided by meteorological stations in the Lublin City center and its nearest surroundings. Floristic data were collected during field studies between 2012–2014 and included species richness and frequency, life forms, and synecological groups of the flora and its elements. The thermal requirements of species were defined on the basis of ecological indicator values (EIVs). Our research confirmed the presence of the UHI in the Lublin City center. Over the study period, the mean temperature in the city center was by 0.87°C higher than that in the suburban areas. The largest differences in mean annual air temperature between the city center and the suburbs were recorded in 2007 and 2011–2013. In total, 552 species were recorded, including six life-form and synecological groups, 246 thermophilous and 436 heliophilous species. The species richness, proportion of therophytes, alien, thermo- and heliophilous species decreased with distance from the city center. The thermal conditions expressed by the EIV L and T ranged from L = 4.5, T = 3.8 in the city center, to L = 3.1, T = 3.4 in the suburbs. An ordination analysis facilitated determination of the relationships between characteristics of the flora, the EIV values, and land use classes. An increasing level of anthropopressure was found to be positively correlated with thermal conditions and the flora traits.

scholarly journals Single concentrations of particulate matter PM2,5 and PM10 in the lower layers of the atmosphereof Tobolsk

2021 ◽  
Vol 54 (2) ◽  
pp. 119-126
Author(s):  
Roman Yu. Pozhitkov
Keyword(s):  
Particulate Matter ◽  
Air Temperature ◽  
Suspended Particles ◽  
City Center ◽  
Quantitative Distribution ◽  
Temperature And Humidity ◽  
Functional Zones ◽  
Air Layers ◽  
The City ◽  
And Storage

Abstract. The aim of the work is to determine the single concentrations of particulate matter in the lower layers of the atmosphere of Tobolsk. To achieve this goal, the following tasks were set: to determine the amount of PM2,5 and PM10 in various functional zones of the city; to create schemes for the quantitative distribution of suspended particles throughout the city; to localize areas with high levels of pollution for further monitoring; to analyze the influence of certain meteorological indicators (temperature and humidity air) on the content of suspended particles. The measurements were performed according to the repeatedly tested method using the AIR TESTER CW-HAT 200 device. It is established that in the lowers air layers of Tobolsk the content of PM2,5 and PM10 is low, the average geometric values are 5 and 7 ug/m3, respectively, which is significantly lower than the established maximum single concentrations for this indicator. The lowest values were found in the industrial and utility and storage zones, the highest values were found near the highway zone and in the city center, which suggests that the main source of PM2. 5 and PM10 is vehicles. Two sites with an increased level of pollution by suspended particles were localized. There were no significant correlations between PM2,5 and PM10 concentrations and air temperature and humidity.

scholarly journals How the urban environment affects the microclimate and the building energy demand for the City of Rome

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1035-1042 ◽  
Author(s):  
Andrea Vallati ◽  
Luca Mauri ◽  
Chiara Colucci
Keyword(s):  
Urban Heat Island ◽  
Urban Environment ◽  
Urban Area ◽  
Air Temperature ◽  
Energy Demand ◽  
The Other ◽  
Weather Data ◽  
Heat Island ◽  
Urban Heat ◽  
The City

Urban heat island has significant impacts on buildings? energy consumption. The phenomenon is associated with increased urban air temperatures compared to the air temperature of the surrounding rural or suburban areas. The ambient air temperature growth due to climate changes and the urban heat island phenomenon are dramatically increasing the cooling demand in buildings. This is worsened by irradiation conditions, construction technologies, and subjective comfort expectations. This paper examines the impact of the urban environment on the energy demand of buildings, considering the case of two districts of the city of Rome, Italy: one is representative of a central zone, the other of a rural zone. Weather data were then used to calculate the thermal demand of a typical Italian building, ideally located in the monitored areas of the city. Standalone building with modified weather file was modeled in TRNSYS. Results show that urban heat island intensity causes an increase in cooling demand up to +33% for the urban area (+20% for the rural area) compared to the demand calculated using weather data from airportual areas. On the other hand, urban heat island intensity has a positive effect on heating demand which turns out to decrease up to -32% for the urban area (-14% for the rural area).

scholarly journals Variações Termo-Higrométricas e Estudo de Ilha de Calor Urbana na Cidade de Bragança-PA e Circunvizinhança (Thermo-Hygrometric Variations and Study of Urban Heat Island in the City of Bragança-PA and Surrounding Region)

2016 ◽  
Vol 9 (2) ◽  
pp. 571
Author(s):  
Abnoã Da Costa Costa ◽  
Hernani Rodrigues ◽  
Jefferson Costa ◽  
Paulo Souza ◽  
Joao Silva Junior ◽  
...  
Keyword(s):  
Air Temperature ◽  
Meteorological Parameters ◽  
Heat Island ◽  
Urban Centers ◽  
Heat Islands ◽  
Urban Heat ◽  
Relationship Of ◽  
The Relationship ◽  
The City

Estudou-se algumas variáveis e parâmetros meteorológicos no período de 17 a 21 de novembro de 2014, na cidade de Bragança-PA e circunvizinhança, com a finalidade de entender como elas interferem no microclima da cidade e com isso fazer um estudo com a finalidade de obter uma breve característica do microclima na região. Os resultados mostraram que houveram diferenças de temperaturas entre os pontos, ou seja, algumas características de cada local influenciaram no aumento ou diminuição da temperatura do ar. A relação dos dados com as características de uso e ocupação do solo demonstrou uma influência significativa onde havia vegetação, devido a diminuição da temperatura do ar noturna e, consequentemente, minimização das ilhas de calor. Foi verificado também que as áreas com maior ocupação com construções e com maior pavimentação perderam menos calor, levando à formação de pequenas ilhas de calor noturnas mais intensas. Assim percebeu-se que na cidade, bem como aquelas que passaram por processos de urbanização, segundo literatura, possuem ilha de calor, que consiste em temperaturas mais elevadas durante a noite, causando assim o desconforto humano. Com isso, as alterações microclimáticas na cidade de Bragança-PA, assim como em outros centros urbanos, em geral são causadas pela ação antrópica e que interferem na qualidade de vida da população. Este trabalho é importante para a publicação nesta revista devida a sua contribuição cientifica para a sociedade.     A B S T R A C T We studied some variables and meteorological parameters in the period from 17 to 21 November 2014 in the city of Bragança-PA and surrounding region, in order to understand how they impact on the city's microclimate and thus make a study for the purpose of get a brief characteristic of the microclimate in the region. The results showed that there were differences in temperature between the points, that is, some features of each local influence on the increase or decrease of air temperature. The relationship of the data with the characteristics of use and land cover showed a significant influence where there was vegetation, because influenced the decrease in the night air temperature and thus minimize heat islands. It was also found that the areas with higher occupancy with buildings and more paving lost less heat, leading to the formation of smaller more intense nocturnal heat islands. So it was noticed that in the city, as well as those who have gone through processes of urbanization, according to literature, have heat island, consisting of higher temperatures during the night, thus causing certain human discomfort. With that, the microclimate changes in the city of Bragança-PA, as well as other urban centers in general are caused by human activities that interfere with people's quality of life. This work is important for publication in the magazine due to their scientific contribution to society Keywords: Bragança-PA, heat island, air temperature.   

scholarly journals Estimating the Urban Heat Island Contribution to Urban and Rural Air Temperature Differences over Complex Terrain: Application to an Arid City

2010 ◽  
Vol 49 (10) ◽  
pp. 2159-2166 ◽  
Author(s):  
Hadas Saaroni ◽  
Baruch Ziv
Keyword(s):  
Urban Heat Island ◽  
Air Temperature ◽  
Complex Terrain ◽  
Order Approximation ◽  
Temperature Record ◽  
Heat Island ◽  
Regional Warming ◽  
Study Region ◽  
Urban Heat ◽  
The City

Abstract This study proposes a method for estimating the canopy-layer net urban heat island (UHI) in regions with complex terrain that lack preurban observations. The approach is based on a linear relationship between the urban–rural temperature difference (ΔTu−r), measured via screen-level air temperature, and the population of the city, which was found to have the highest correlation with observations. The linear relation is extrapolated to zero population to yield the desired preurban value. The difference between the zero population ΔTu−r and the current one is proposed to represent the net UHI. Given the uncertainties of the population method, the relatively short time period of the temperature record, and possible inhomogeneity in the data, the results should be regarded as a first-order approximation of the net UHI contribution. The UHI was evaluated for an arid city, Beer Sheba, Israel, for the minimum and maximum air temperatures for the summer and the winter. The study region resembles the combined effect of complex terrain (i.e., the concave topography of the city in contrast with the plateau landscape surrounding it), the UHI, and the regional warming trend. The study assumes that the regional warming does not affect the ΔTu−r. The concave topography of the city dominates over the UHI contribution during nighttime, resulting in an average lower minimum temperature in the city relative to the rural area. This difference has decreased considerably during the study period and has even reversed for the summer nights toward the end of the period. The estimated net UHI contribution in Beer Sheba varies between +0.8° and +3.1°C, with the highest values during the night hours. The high positive UHI during the night is in line with previous studies. The positive UHI in the summer implies further aggravation of heat stress beyond that occurring, and that predicted to increase, over the region.

scholarly journals Relating urban development and densification to temporary changes in the air temperature in Warsaw (Poland)

2020 ◽  
Vol 142 (1-2) ◽  
pp. 513-523
Author(s):  
Tomasz Rozbicki ◽  
Małgorzata Kleniewska ◽  
Katarzyna Rozbicka ◽  
Grzegorz Majewski ◽  
Dariusz Gołaszewski
Keyword(s):  
Air Temperature ◽  
Surface Energy Balance ◽  
Thermal Conditions ◽  
Active Surface ◽  
City Centre ◽  
Heat Island ◽  
Temperature Trends ◽  
Urban Heat ◽  
The City

Abstract The assessment of the influence of urbanisation effects on air temperature trends has been widely discussed in the literature. Urbanisation affects the urban active surface energy balance, resulting in the formation of urban heat island, also observed in the Warsaw conurbation. This article presents the diversity of long-term changes in air temperature at three Warsaw meteorological stations situated in the districts of Ursynów, Okęcie and Bielany, and demonstrates changes in thermal conditions during a long-term urbanisation process. Ursynów is the station where the changes of the surrounding area were most significant among the three analysed ones and the rise in the air temperature for this station was the greatest and it was observed from 7.5 °C in the years 1961–1970 to 8.5 °C in the years 2001–2010. The diversity of air temperature between the stations depends on their location. All of them are situated within the conurbation, at some distance from the city centre but the nature of their surroundings is different. The diversity applies to all annual characteristics of air temperature: its mean, mean maximum and mean minimum values.

Sign in / Sign up

Export Citation Format

Share Document