How urban expansion affects the thermal environment? A study of the impact of natural cities on the thermal field value and footprint of thermal environment

Rapid urbanization has become a major urban sustainability concern due to environmental impacts, such as the development of urban heat island (UHI) and the reduction of urban security states. To date, most research on urban sustainability development has focused on dynamic change monitoring or UHI state characterization, while there is little literature on UHI change analysis. In addition, there has been little research on the impact of land use and land cover changes (LULCCs) on UHI, especially simulates future trends of LULCCs, UHI change, and dynamic relationship of LULCCs and UHI. The purpose of this research is to design a remote sensing-based framework that investigates and analyzes how the LULCCs in the process of urbanization affected thermal environment. In order to assess and predict the impact of LULCCs on urban heat environment, multitemporal remotely sensed data from 1986 to 2016 were selected as source data, and Geographic Information System (GIS) methods such as the CA-Markov model were employed to construct the proposed framework. The results showed that (1) there has been a substantial strength of urban expansion during the 40-year study period, (2) the farthest distance urban center of gravity moves from north-northeast (NEE) to west-southwest (WSW) direction, (3) the dominate temperature was middle level, sub-high level, and high level in the research area, (4) there was a higher changing frequency and range from east to west, and (5) there was a significant negative correlation between land surface temperature and vegetation and significant positive correlation between temperature and human settlement.

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Spatial heterogeneity of the thermal environment based on the urban expansion of natural cities using open data in Guangzhou, China

Ecological Indicators ◽

10.1016/j.ecolind.2019.05.032 ◽

2019 ◽

Vol 104 ◽

pp. 524-534 ◽

Cited By ~ 5

Author(s):

Zhiwei Yang ◽

Yingbiao Chen ◽

Zhifeng Wu ◽

Qinglan Qian ◽

Zihao Zheng ◽

...

Keyword(s):

Spatial Heterogeneity ◽

Thermal Environment ◽

Urban Expansion ◽

Open Data ◽

Natural Cities

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Assessing the impact of urban expansion to the state of thermal environment of peri-urban areas using indices

Urban Climate ◽

10.1016/j.uclim.2015.10.004 ◽

2015 ◽

Vol 14 ◽

pp. 166-175 ◽

Cited By ~ 6

Author(s):

Anastasios Polydoros ◽

Constantinos Cartalis

Keyword(s):

Urban Areas ◽

Thermal Environment ◽

Urban Expansion ◽

The State ◽

The Impact

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Impact of LULC Changes on LST in Rajshahi District of Bangladesh: A Remote Sensing Approach

Journal of Geographical Studies ◽

10.21523/gcj5.19030102 ◽

2020 ◽

Vol 3 (1) ◽

pp. 11-23 ◽

Cited By ~ 3

Author(s):

Abdulla Al Kafy ◽

Abdullah Al-Faisal ◽

Mohammad Mahmudul Hasan ◽

Md. Soumik Sikdar ◽

Mohammad Hasib Hasan Khan ◽

...

Keyword(s):

Remote Sensing ◽

Surface Temperature ◽

Land Surface ◽

Agricultural Land ◽

Global Climate ◽

Urban Expansion ◽

Water Bodies ◽

Landsat 8 ◽

Lulc Changes ◽

The Impact

Urbanization has been contributing more in global climate warming, with more than 50% of the population living in cities. Rapid population growth and change in land use / land cover (LULC) are closely linked. The transformation of LULC due to rapid urban expansion significantly affects the functions of biodiversity and ecosystems, as well as local and regional climates. Improper planning and uncontrolled management of LULC changes profoundly contribute to the rise of urban land surface temperature (LST). This study evaluates the impact of LULC changes on LST for 1997, 2007 and 2017 in the Rajshahi district (Bangladesh) using multi-temporal and multi-spectral Landsat 8 OLI and Landsat 5 TM satellite data sets. The analysis of LULC changes exposed a remarkable increase in the built-up areas and a significant decrease in the vegetation and agricultural land. The built-up area was increased almost double in last 20 years in the study area. The distribution of changes in LST shows that built-up areas recorded the highest temperature followed by bare land, vegetation and agricultural land and water bodies. The LULC-LST profiles also revealed the highest temperature in built-up areas and the lowest temperature in water bodies. In the last 20 years, LST was increased about 13ºC. The study demonstrates decrease in vegetation cover and increase in non-evaporating surfaces with significantly increases the surface temperature in the study area. Remote-sensing techniques were found one of the suitable techniques for rapid analysis of urban expansions and to identify the impact of urbanization on LST.

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Sources of and Control Measures for PTE Pollution in Soil at the Urban Fringe in Weinan, China

Land ◽

10.3390/land10070762 ◽

2021 ◽

Vol 10 (7) ◽

pp. 762

Author(s):

Lei Han ◽

Rui Chen ◽

Zhao Liu ◽

Shanshan Chang ◽

Yonghua Zhao ◽

...

Keyword(s):

Land Use ◽

Urban Expansion ◽

Pollution Sources ◽

Urban Fringe ◽

Control Measures ◽

Atomic Fluorescence Spectrometry ◽

Human Beings ◽

Rapid Urbanization ◽

Kriging Interpolation Method ◽

The Impact

The environment of the urban fringe is complex and frangible. With the acceleration of industrialization and urbanization, the urban fringe has become the primary space for urban expansion, and the intense human activities create a high risk of potentially toxic element (PTE) pollution in the soil. In this study, 138 surface soil samples were collected from a region undergoing rapid urbanization and construction—Weinan, China. Concentrations of As, Pb, Cr, Cu, and Ni (Inductively Coupled Plasma Mass Spectrometry, ICP-MS) and Hg (Atomic Fluorescence Spectrometry, AFS) were measured. The Kriging interpolation method was used to create a visualization of the spatial distribution characteristics and to analyze the pollution sources of PTEs in the soil. The pollution status of PTEs in the soil was evaluated using the national environmental quality standards for soils in different types of land use. The results show that the content range of As fluctuated a small amount and the coefficient of variation is small and mainly comes from natural soil formation. The content of Cr, Cu, and Ni around the automobile repair factory, the prefabrication factory, and the building material factory increased due to the deposition of wear particles in the soil. A total of 13.99% of the land in the study area had Hg pollution, which was mainly distributed on category 1 development land and farmland. Chemical plants were the main pollution sources. The study area should strictly control the industrial pollution emissions, regulate the agricultural production, adjust the land use planning, and reduce the impact of pollution on human beings. Furthermore, we make targeted remediation suggestions for each specific land use type. These results are of theoretical significance, will be of practical value for the control of PTEs in soil, and will provide ecological environmental protection in the urban fringe throughout the urbanization process.

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Mapping 20 Years of Urban Expansion in 45 Urban Areas of Sub-Saharan Africa

Remote Sensing ◽

10.3390/rs13030525 ◽

2021 ◽

Vol 13 (3) ◽

pp. 525

Author(s):

Yann Forget ◽

Michal Shimoni ◽

Marius Gilbert ◽

Catherine Linard

Keyword(s):

Case Studies ◽

Urban Areas ◽

Urban Expansion ◽

Local Population ◽

Sub Saharan Africa ◽

Annual Growth Rate ◽

Urban Dynamics ◽

Mapping Approach ◽

Sub Saharan ◽

The Impact

By 2050, half of the net increase in the world’s population is expected to reside in sub-Saharan Africa (SSA), driving high urbanization rates and drastic land cover changes. However, the data-scarce environment of SSA limits our understanding of the urban dynamics in the region. In this context, Earth Observation (EO) is an opportunity to gather accurate and up-to-date spatial information on urban extents. During the last decade, the adoption of open-access policies by major EO programs (CBERS, Landsat, Sentinel) has allowed the production of several global high resolution (10–30 m) maps of human settlements. However, mapping accuracies in SSA are usually lower, limited by the lack of reference datasets to support the training and the validation of the classification models. Here we propose a mapping approach based on multi-sensor satellite imagery (Landsat, Sentinel-1, Envisat, ERS) and volunteered geographic information (OpenStreetMap) to solve the challenges of urban remote sensing in SSA. The proposed mapping approach is assessed in 17 case studies for an average F1-score of 0.93, and applied in 45 urban areas of SSA to produce a dataset of urban expansion from 1995 to 2015. Across the case studies, built-up areas averaged a compound annual growth rate of 5.5% between 1995 and 2015. The comparison with local population dynamics reveals the heterogeneity of urban dynamics in SSA. Overall, population densities in built-up areas are decreasing. However, the impact of population growth on urban expansion differs depending on the size of the urban area and its income class.

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A cooled city? Comparing human activity changes on the impact of urban thermal environment before and after city-wide lockdown

Building and Environment ◽

10.1016/j.buildenv.2021.107729 ◽

2021 ◽

Vol 195 ◽

pp. 107729

Author(s):

Zhi Cai ◽

Yan Tang ◽

Qingming Zhan

Keyword(s):

Human Activity ◽

Thermal Environment ◽

Before And After ◽

Urban Thermal Environment ◽

The Impact

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Assessing the Impact of Urban Expansion on Surrounding Forested Landscape Connectivity across Space and Time

Land ◽

10.3390/land10040359 ◽

2021 ◽

Vol 10 (4) ◽

pp. 359

Author(s):

Zhouqiao Ren ◽

Jianhua He ◽

Qiaobing Yue

Keyword(s):

Landscape Connectivity ◽

Urban Expansion ◽

Landscape Fragmentation ◽

Sustainable Urban Development ◽

Delayed Response ◽

Conservation Practices ◽

Rapid Urbanization ◽

Dynamic Landscapes ◽

The Impact ◽

Over Time

Landscape connectivity is important for all organisms as it directly affects population dynamics. Yet, rapid urbanization has caused serious landscape fragmentation, which is the primary contributor of species extinctions worldwide. Previous studies have mostly used spatial snap-shots to evaluate the impact of urban expansion on landscape connectivity. However, the interactions among habitats over time in dynamic landscapes have been largely ignored. Here, we demonstrated that overlooking temporal connectivity can lead to the overestimation of the impact of urban expansion. How much greater the overestimation is depends on the amount of net habitat loss. Moreover, we showed that landscape connectivity may have a delayed response to urban expansion. Our analysis shifts the way to understand the ecological consequences of urban expansion. Our framework can guide sustainable urban development and can be inspiring to conservation practices under other contexts (e.g., climate change).

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Spatio-temporal variation of water supply in Guizhou Province, China

Water Policy ◽

10.2166/wp.2016.036 ◽

2016 ◽

Vol 19 (1) ◽

pp. 181-195 ◽

Cited By ~ 3

Author(s):

Huiqing Han ◽

Yuxiang Dong

Keyword(s):

Land Use ◽

Water Supply ◽

Urban Expansion ◽

Guizhou Province ◽

Water Yield ◽

Freshwater Ecosystem ◽

Yield Model ◽

Invest Model ◽

Spatio Temporal ◽

The Impact

Water supply is an important freshwater ecosystem service provided by ecosystems. Water shortages resulting from spatio-temporal heterogeneity of climate condition or human activities present serious problems in the Guizhou Province of southwest China. This study aimed to analyze the spatio-temporal changes of water supply service using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, explore how climate and land-use changes impact water supply provision, and discuss the impact of parameters associated with climate and land-use in the InVEST model on water supply in the region. We used data and the model to forecast trends for the year 2030 and found that water supply has been declining in the region at the watershed scale since 1990. Climate and land-use change played important roles in affecting the water supply. Water supply was overwhelmingly driven by the reference evapotranspiration and annual average precipitation, while the plant evapotranspiration coefficients for each land-use type had a relatively small effect. The method for sensitivity analysis developed in this study allowed exploration of the relative importance of parameters in the InVEST water yield model. The Grain-for-Green project, afforestation, and urban expansion control should be accelerated in this region to protect the water supply.

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Free vibration analysis and post-critical free vibrations of nanocomposite rotating beams reinforced with graphene platelet

Journal of Vibration and Control ◽

10.1177/10775463211051187 ◽

2021 ◽

pp. 107754632110511

Author(s):

Arameh Eyvazian ◽

Chunwei Zhang ◽

Farayi Musharavati ◽

Afrasyab Khan ◽

Mohammad Alkhedher

Keyword(s):

Natural Frequency ◽

Thermal Environment ◽

Rotational Velocity ◽

Equations Of Motion ◽

Free Vibration Analysis ◽

Beam Theory ◽

Weight Fraction ◽

Free Vibrations ◽

Graphene Platelet ◽

The Impact

Treatment of the first natural frequency of a rotating nanocomposite beam reinforced with graphene platelet is discussed here. In regard of the Timoshenko beam theory hypothesis, the motion equations are acquired. The effective elasticity modulus of the rotating nanocomposite beam is specified resorting to the Halpin–Tsai micro mechanical model. The Ritz technique is utilized for the sake of discretization of the nonlinear equations of motion. The first natural frequency of the rotating nanocomposite beam prior to the buckling instability and the associated post-critical natural frequency is computed by means of a powerful iteration scheme in reliance on the Newton–Raphson method alongside the iteration strategy. The impact of adding the graphene platelet to a rotating isotropic beam in thermal ambient is discussed in detail. The impression of support conditions, and the weight fraction and the dispersion type of the graphene platelet on the acquired outcomes are studied. It is elucidated that when a beam has not undergone a temperature increment, by reinforcing the beam with graphene platelet, the natural frequency is enhanced. However, when the beam is in a thermal environment, at low-to-medium range of rotational velocity, adding the graphene platelet diminishes the first natural frequency of a rotating O-GPL nanocomposite beam. Depending on the temperature, the post-critical natural frequency of a rotating X-GPL nanocomposite beam may be enhanced or reduced by the growth of the graphene platelet weight fraction.

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