Assessing effects of urban vegetation height on land surface temperature in the City of Tampa, Florida, USA

Author(s):  
Qiuyan Yu ◽  
Michael Acheampong ◽  
Ruiliang Pu ◽  
Shawn M. Landry ◽  
Wenjie Ji ◽  
...  
Author(s):  
Georgiana Grigoraș ◽  
Bogdan Urițescu

Abstract The aim of the study is to find the relationship between the land surface temperature and air temperature and to determine the hot spots in the urban area of Bucharest, the capital of Romania. The analysis was based on images from both moderate-resolution imaging spectroradiometer (MODIS), located on both Terra and Aqua platforms, as well as on data recorded by the four automatic weather stations existing in the endowment of The National Air Quality Monitoring Network, from the summer of 2017. Correlation coefficients between land surface temperature and air temperature were higher at night (0.8-0.87) and slightly lower during the day (0.71-0.77). After the validation of satellite data with in-situ temperature measurements, the hot spots in the metropolitan area of Bucharest were identified using Getis-Ord spatial statistics analysis. It has been achieved that the “very hot” areas are grouped in the center of the city and along the main traffic streets and dense residential areas. During the day the "very hot spots” represent 33.2% of the city's surface, and during the night 31.6%. The area where the mentioned spots persist, falls into the "very hot spot" category both day and night, it represents 27.1% of the city’s surface and it is mainly represented by the city center.


2021 ◽  
Vol 13 (2) ◽  
pp. 323
Author(s):  
Liang Chen ◽  
Xuelei Wang ◽  
Xiaobin Cai ◽  
Chao Yang ◽  
Xiaorong Lu

Rapid urbanization greatly alters land surface vegetation cover and heat distribution, leading to the development of the urban heat island (UHI) effect and seriously affecting the healthy development of cities and the comfort of living. As an indicator of urban health and livability, monitoring the distribution of land surface temperature (LST) and discovering its main impacting factors are receiving increasing attention in the effort to develop cities more sustainably. In this study, we analyzed the spatial distribution patterns of LST of the city of Wuhan, China, from 2013 to 2019. We detected hot and cold poles in four seasons through clustering and outlier analysis (based on Anselin local Moran’s I) of LST. Furthermore, we introduced the geographical detector model to quantify the impact of six physical and socio-economic factors, including the digital elevation model (DEM), index-based built-up index (IBI), modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), population, and Gross Domestic Product (GDP) on the LST distribution of Wuhan. Finally, to identify the influence of land cover on temperature, the LST of croplands, woodlands, grasslands, and built-up areas was analyzed. The results showed that low temperatures are mainly distributed over water and woodland areas, followed by grasslands; high temperatures are mainly concentrated over built-up areas. The maximum temperature difference between land covers occurs in spring and summer, while this difference can be ignored in winter. MNDWI, IBI, and NDVI are the key driving factors of the thermal values change in Wuhan, especially of their interaction. We found that the temperature of water area and urban green space (woodlands and grasslands) tends to be 5.4 °C and 2.6 °C lower than that of built-up areas. Our research results can contribute to the urban planning and urban greening of Wuhan and promote the healthy and sustainable development of the city.


Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 123 ◽  
Author(s):  
Guglielmina Mutani ◽  
Valeria Todeschi

There is growing attention to the use of greenery in urban areas, in various forms and functions, as an instrument to reduce the impact of human activities on the urban environment. The aim of this study has been to investigate the use of green roofs as a strategy to reduce the urban heat island effect and to improve the thermal comfort of indoor and outdoor environments. The effects of the built-up environment, the presence of vegetation and green roofs, and the urban morphology of the city of Turin (Italy) have been assessed considering the land surface temperature distribution. This analysis has considered all the information recorded by the local weather stations and satellite images, and compares it with the geometrical and typological characteristics of the city in order to find correlations that confirm that greenery and vegetation improve the livability of an urban context. The results demonstrate that the land-surface temperature, and therefore the air temperature, tend to decrease as the green areas increase. This trend depends on the type of urban context. Based on the results of a green-roofs investigation of Turin, the existing and potential green roofs are respectively almost 300 (257,380 m2) and 15,450 (6,787,929 m2). Based on potential assessment, a strategy of priority was established according to the characteristics of building, to the presence of empty spaces, and to the identification of critical areas, in which the thermal comfort conditions are poor with low vegetation. This approach can be useful to help stakeholders, urban planners, and policy makers to effectively mitigate the urban heat island (UHI), improve the livability of the city, reduce greenhouse gas (GHG) emissions and gain thermal comfort conditions, and to identify policies and incentives to promote green roofs.


2020 ◽  
Author(s):  
Mikias Biazen Molla

Abstract This investigation was conducted for the estimation of the temporal land surface temperature value using thermal remote sensing of Landsat-8 (OLI) Data in Hawassa City Administration, Ethiopia. Satellite datasets of Landsat-7 (ETM+) for 22nd March 2002 and Landsat-8 (OLI) of 22nd March 2019 were taken for this study. Different algorisms were used to estimate the Normalized Difference Vegetation Index threshold from the Red and Near-Infrared band and the ground earth's surface emissivity esteem is legitimately recovered from the thermal infrared by coordinating with the outcome got from MODIS information. The land use land cover map of the city was prepared with better accuracy using the on-screen classification technique. The spatial distribution of surface temperature of the city range from 6.62°C to 22.54°C with a mean of 14.58°C and a standard deviation of 11.25 in the year of march 22nd 2002. The LST result derived from Landsat 8 for March 22nd, 2019, ranges from 11.97°C to 35.5°C with a mean of 23.735 °C and a standard deviation of 16.64. In both years the higher LST values correspond to built-up/settlement and bare/open lands of the city; whereas, lower LST values were observed in vegetation (trees/woodlot, shrubs, and grass forested) area. Urban expansion (built-up area roads, and another impervious surface), decline in vegetation levels due to deforestation and increasing population density. Increasing an evergreen tree and green space coverage, design and develop city parks and rehabilitate the existing degraded natural environments are among the recommended strategy to reduce the rate of LST.


GEOgraphia ◽  
2021 ◽  
Vol 23 (50) ◽  
Author(s):  
Diego de Sousa Ribeiro Fonseca ◽  
Ricardo Alexandrino Garcia

O objetivo deste estudo foi determinar as áreas que têm tido maior propensão para ocorrência de infectados pela dengue na cidade Montes Claros-MG. A metodologia consistiu na aquisição de dados relativos ao número de infectados pela dengue, por bairros, nos anos 2015, 2016 e 2017; obtenção dos Índices Breteaures sobre infestação larvária pelo Aedes aegypti nos respectivos anos; uso de imagens de satélite para estimação da temperatura de superfície (TSE); aquisição de dados sobre elevação do terreno e renda familiar. Posteriormente, foi realizada a organização do banco de dados; emprego da análise descritiva; aplicação da regressão linear múltipla e da interpolação. O uso do modelo regressivo múltiplo, StepWise progressivo, para seleção das variáveis preditoras, com maior poder para explicação dos surtos de dengue ocorridos no período, mostrou-se eficiente, permitindo que fosse operacionalizada a co-krigagem, a qual trouxe as regiões sob maior probabilidade da ocorrência de infectados pela dengue. Genericamente, a infestação larvária pelo Aedes aegypti tem acontecido na porção oeste, enquanto a infecção pela dengue tem maior propensão na porção leste da cidade.Palavras-chave: infectados; infestação larvária; temperatura de superfície; altitude; renda domiciliar. ZONNING AREAS WITH THE BIGGEST PROPENTION TO SICK PEOPLE BY DENGUE IN THE MONTES CLAROS CITY (MG) USING SOCIO ENVIRONMENTAL VARIABLES AND GEOSTATISTICS Abstract: The objective of this work was to delimitation the determinats areas with the most propention to occurrence of sick peoples by dengue in the Montes Claros city, Minas Gerais. The methodology was consists in the acquisition of databases relateded at infects numbers by dengue, by neighborhoods, betwen the years 2015, 2016 and 2017; obtaining of Breteau Index about larval infestation by Aedes aegypti in the related years; use of satelities imagery to estimation of land surface temperature (LST); acquisition of databases about land elevation and familiar income. In the next time, was realize the organization of databases; employing the descriptive analysis; application of multiple linear regretion and interpolation of files. The use of regressive model, progressing StepWise, to selection of predictive variables, with more po explication power to disease outbreaks in the period, showed efficient, and this was permited the operationabilization of the co-kriging, which brought the regions with the more probability to dengue infectation. Overall, the larval infestation by the Aedes aegypti had happened on the west side, while the infectation by dengue have been more propention on the east side of the city, two portions in different economic situations, where the western part concentrates the population with the highest income. This factor denotes the fragility of the low-income population in terms of public health and their greater lack of strategic attention.Keywords: infected; larval infestation; land surface temperature; elevation; familiar income. ZONIFICACIÓN DE UBICACIONES CON MAYOR PROPENSIÓN PARA DENGUE DENTRO DE LA CIUDAD DE MONTES CLAROS (MG) A PARTIR DE VARIABLES SOCIOAMBIENTALES Y GEOSTATISTICAS Resumen: El objetivo de este estudio fue determinar las áreas que han sido más propensas a la ocurrencia de infectados por la dengue en la ciudad Montes Claros-MG. La metodología consistió en adquirir datos sobre el número de personas infectadas por dengue, en los barrios, en los años 2015, 2016 y 2017; obtención de los Índices de Breteaures sobre infestación larvaria por Aedes aegypti en los años respectivos; uso de imágenes de satélite para estimar la temperatura de la superficie (TS); adquisición de datos sobre elevación del terreno e ingresos familiares. Posteriormente, se organizó la base de datos; se hizo uso de análisis descriptivo; aplicación de interpolación y regresión lineal múltiple. El uso del modelo regresivo múltiple, progresivo StepWise, para seleccionar las variables predictoras, con mayor poder para explicar lo fenómeno de la dengue ocurridos en el período, resultó ser eficiente, permitiendo la operacionalización de la co-kriging, lo que llevó a las regiones bajo mayor probabilidad de personas infectadas con dengue. Generalmente, la infestación de larvas por el Aedes aegypti ha ocurrido en la parte occidental, mientras que la infección por la dengue es más probable en la parte oriental de la ciudad, dos partes en situaciones económicas diferentes, donde la parte occidental concentra la población de mayores ingresos. Este factor denota la fragilidad de la población de bajos ingresos en materia de salud pública y su mayor falta de atención estratégica.Palabras Clave: infectado; infestación de larvas; temperatura de la superficie; altitud; ingresos del hogar.


Author(s):  
P. Nwaerema ◽  
Ojeh N. Vincent ◽  
C. Amadou ◽  
Atuma, I. Morrison

The study examined Land Surface Temperature (LST) and Land Surface Emissivity (LSE) in a tropical coastal city of Port Harcourt and its environs. Satellite remote sensing of multiple-wavelength origin was employed to derive data from the Landsat Enhance Thematic Mapper (ETM+). Statistical mean and range were used to show pattern of LST and LSE. The study established the relationship and characteristics of land use land cover, built-up area and influence of population on land surfaces. With population of over 3,095,342 persons occupying surface area of approximately 458,28 Km2, rapid vegetal and water body lost have put the city area under pressure of 4.7°C heat bias at the interval of 15 years. From rural fringes to the city center, LST varies with 9.3°C in wet season and 4.8°C in the dry season. During the dry season, LSE is severe in the southern part of the city contributed by water bodies, more vegetal cover and urban pavement materials. Emissivity in the wet season varied with 0.0136 and 0.0006 during the dry season but differs with 0.0165 between the two seasons. One critical finding is that LSE decreases from the rural fringes to the city center and LST increases from the rural fringes to the city center. It is recommended that urban greening at the city center should be practiced and the rural fringes should be explored by decongesting activities at the city center to the outskirts in order to ameliorate the effects of urban heat bias without further delay.


2019 ◽  
Vol 11 (2) ◽  
pp. 182 ◽  
Author(s):  
Yongjiu Feng ◽  
Chen Gao ◽  
Xiaohua Tong ◽  
Shurui Chen ◽  
Zhenkun Lei ◽  
...  

Land surface temperature (LST) is a fundamental Earth parameter, on both regional and global scales. We used seven Landsat images to derive LST at Suzhou City, in spring and summer 1996, 2004, and 2016, and examined the spatial factors that influence the LST patterns. Candidate spatial factors include (1) land coverage indices, such as the normalized difference built-up index (NDBI), the normalized difference vegetation index (NDVI), and the normalized difference water index (NDWI), (2) proximity factors such as the distances to the city center, town centers, and major roads, and (3) the LST location. Our results showed that the intensity of the surface urban heat island (SUHI) has continuously increased, over time, and the spatial distribution of SUHI was different between the two seasons. The SUHIs in Suzhou were mainly distributed in the city center, in 1996, but expanded to near suburban, in 2004 and 2016, with a substantial expansion at the highest level of SUHIs. Our buffer-zone-based gradient analysis showed that the LST decays logarithmically, or decreases linearly, with the distance to the Suzhou city center. As inferred by the generalized additive models (GAMs), strong relationships exist between the LST and the candidate factors, where the dominant factor was NDBI, followed by NDWI and NDVI. While the land coverage indices were the LST dominant factors, the spatial proximity and location also substantially influenced the LST and the SUHIs. This work improved our understanding of the SUHIs and their impacts in Suzhou, and should be helpful for policymakers to formulate counter-measures for mitigating SUHI effects.


Sign in / Sign up

Export Citation Format

Share Document