scholarly journals Calculating the water dissipation of buildings in urban areas based on global nighttime light data

2021 ◽  
Author(s):  
Han Gao ◽  
Jiahong Liu ◽  
Chao Mei ◽  
Wang Hao ◽  
Weiwei Shao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Developing Economies ◽  
Calculation Model ◽  
Urban Water ◽  
Heat Island ◽  
Floor Area ◽  
Island Effect ◽  
Nighttime Light Data ◽  
Basic Understanding ◽  
Nighttime Light

Abstract Urban water dissipation is increasing gradually as urbanization progresses. Urban water dissipation mainly includes the dissipation of water in buildings and natural water evapotranspiration. Previous studies have mainly focused on calculating natural evapotranspiration in urban areas and have overlooked the dissipation of water in buildings under the influence of strong human-related water use activities. In this paper, the concept of building water dissipation (BWD) was proposed to describe the phenomenon that water dissipation occurs inside buildings. Moreover, a BWD calculation model was established and applied to calculate global building water dissipation. To reveal the specific water dissipation inside buildings, it is necessary to obtain the urban building floor area first. This paper proposed a new method to calculate the urban building floor area based on global nighttime light data obtained from NPP-VIIRS. Taking the floor area results into the BWD calculation model, the global building water dissipation in urban areas was found to be 127 billion m3 in 2015. The vast building water dissipation that occurs in urban areas mostly results from rapidly developing economies and intense human activities. The results provide a basic understanding of the nexus between water resources and the energy-heat island effect in urban areas.

scholarly journals Research on spatial characteristics of metropolis development using nighttime light data: NTL based spatial characteristics of Beijing

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242663
Author(s):  
Yuli Yang ◽  
Mingguo Ma ◽  
Xiaobo Zhu ◽  
Wei Ge
Keyword(s):  
Urban Areas ◽  
Urban Land Use ◽  
Rapid Urbanization ◽  
Spatial Characteristics ◽  
Spatial And Temporal Scales ◽  
Island Effect ◽  
Nighttime Light Data ◽  
Nighttime Light ◽  
Urban Heat ◽  
Research Period

As the capital and one of the metropolises in China, Beijing has met with a number of serious so-called "urban diseases" in the process of rapid urbanization such as blind expansion of urban areas, explosion of population and the increase of urban heat island effect. To treat these “urban diseases” and make the metropolis develop healthful and sustainable in Beijing in the future, the spatial characteristics of metropolis developments in Beijing are explored in this paper. The urban built-up areas in Beijing are extracted using the DMSP-OLS nighttime light data from 1992 to 2013. The characteristics of the urban developments of Beijing are studied, including spatial and temporal scales of urban developments, urban barycenter of Beijing and its transfer trajectory, variations of urban spatial forms and the differences of urban internal developments. The results have shown that the built-up areas had been increasing and circling extending from the central urban areas to the outer spaces in the last 21 years. The built-up area had expanded by 878km2 in 1992–2013, and the built-up area in 2013 had expanded to three times comparing to that of 1992. The expanding area of the built-up area in the northeast is the largest. The expansion of the urban had mainly occurred in 1996–2007, and the expanded area had accounted for 92% of the total research period. During the whole research period, the urban barycenter of Beijing had moved 5000.71 meters towards Northeast 28° of its original place from Dongcheng District to Chaoyang District. The development level of each municipal district had been increasing year by year, and the development differences among the municipal districts had been gradually reduced; the spatial forms of Beijing had been alternately changed between extensive and intensive expansion. The results of this study can help to plan urban land use and people migration of Beijing.

scholarly journals Delineating the Urban Areas of a Cross-Boundary City with Open-Access Data: Guangzhou–Foshan, South China

2021 ◽  
Vol 13 (5) ◽  
pp. 2930
Author(s):  
Pengfei Ban ◽  
Wei Zhan ◽  
Qifeng Yuan ◽  
Xiaojian Li
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
City Size ◽  
Border City ◽  
Point Of Interest ◽  
Nighttime Light Data ◽  
Profile Line ◽  
Point Analysis ◽  
Nighttime Light ◽  
Single Data

Cities defined mainly from the administrative aspect can create impact and problems especially in the case of China. However, only a few researchers from China have attempted to identify urban areas from the morphology dimension. In addition, previous studies have been mostly based on the national and regional scales or a single prefecture city and have completely ignored cross-boundary cities. Defining urban areas on the basis of a single data type also has limitations. To address these problems, this study integrates point of interest and nighttime light data, applies the breaking point analysis method to determine the physical geographic scope of the Guangzhou–Foshan cross-border city, and then compares this city with Beijing and Shanghai. Results show that Guangzhou–Foshan comprises one core urban area and six suburban counties, among which the core urban area extends across the administrative boundaries of Guangzhou and Foshan. The urban area and average urban radius of Guangzhou–Foshan are larger than those of Beijing and Shanghai, and this finding contradicts the city size measurements based on the administrative division system of China and those published on traditional official statistical yearbooks. In terms of urban density value, Shanghai has the steepest profile followed by Guangzhou–Foshan and Beijing, and the profile line of Guangzhou–Foshan has a bimodal shape.

DEVELOPMENT OF A METHOD OF ESTIMATION OF TOTAL FLOOR AREA USING DEEP LEARNING BASED ON NIGHTTIME-LIGHT DATA

2020 ◽  
Vol 76 (6) ◽  
pp. II_1-II_7
Author(s):  
Ryusei SAITO ◽  
Chizuko HIRAI ◽  
Chihiro HAGA ◽  
Takanori MATSUI ◽  
Hiroaki SHIRAKAWA ◽  
...  
Keyword(s):  
Deep Learning ◽  
Floor Area ◽  
Nighttime Light Data ◽  
Nighttime Light

scholarly journals Sustainable Site System

2021 ◽  
Author(s):  
Jorden J. S. Lefler
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Architectural Design ◽  
Heat Island ◽  
Rating Systems ◽  
Island Effect ◽  
Key Points ◽  
Site Design ◽  
The Impact ◽  
The City

This thesis discusses a method of analysing the input of interventions in a building's site design, all of which affect the heat island effect, bio-diversity and hydrology of urban areas. Existing standards from Toronto, Vancouver and Berlin have been researched and analysed. This paper presents an evolution of a method called biotope area factor used in Berlin, Germany. A synthesis of the approach of all three systems was considered and distilled into the key points which were then incorporated into the proposed method. In addition to the impact of an individual building, it also includes the impact from the adjacent street area. The final components of this thesis are the application of the method developed to an urban area in the city of Toronto and results showing the impacts on architectural design from site rating systems.

scholarly journals Response Patterns of Vegetation Phenology along Urban-Rural Gradients in Urban Areas of Different Sizes

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xue Luo ◽  
Yuqing Zhang ◽  
Dongqi Sun
Keyword(s):  
Urban Areas ◽  
Growing Season ◽  
Liaoning Province ◽  
Vegetation Phenology ◽  
Coastal Cities ◽  
Nighttime Light Data ◽  
Urban Rural ◽  
Nighttime Light ◽  
Urban Size ◽  
The Difference

On the basis of MODIS Enhanced Vegetation Index time series data and multisource data, such as nighttime light data and China City Statistical Yearbook data, we investigated the differences in vegetation phenology along urban-rural gradients in urban areas of different sizes between coastal and inland cities in Liaoning Province, China. The results showed that the following: (1) the iterative extraction of urban built-up areas using the threshold method based on nighttime light data combined with the definition of urban built-up areas had high accuracy. (2) Additionally, we found that the start of the growing season (SOS) in Liaoning Province occurred between day 100 and day 180, while the end of the growing season (EOS) occurred between days 260 and 330. The difference in the SOS between coastal cities (i.e., Dalian, Yingkou, Panjin, Jinzhou, Huludao, and Dandong) and inland cities (i.e., Chaoyang, Fuxin, Tieling, Shenyang, Fushun, Liaoyang, Benxi, and Anshan) was 1.70 days. However, the difference in the EOS was more significant, i.e., the EOS in coastal cities occurred 4.47 days later than that in the inland cities. (3) In urban areas of different sizes, the ∆SOS and ∆EOS of inland cities had negative correlations with urban size. Specifically, when the urban size increased 10-fold, the ∆SOS and ∆EOS advanced by 10.03 and 5.71 days, respectively. In contrast, the ∆SOS and ∆EOS of coastal cities had positive and negative correlations with the urban size, respectively. Specifically, when urban size increased 10-fold, ∆SOS was delayed by 11.29 days while EOS was advanced by 8.83 days.

Mapping Global Urban Areas From 2000 to 2012 Using Time-Series Nighttime Light Data and MODIS Products

2019 ◽  
Vol 12 (4) ◽  
pp. 1143-1153 ◽  
Author(s):  
Zuoqi Chen ◽  
Bailang Yu ◽  
Yuyu Zhou ◽  
Hongxing Liu ◽  
Chengshu Yang ◽  
...  
Keyword(s):  
Time Series ◽  
Urban Areas ◽  
Nighttime Light Data ◽  
Nighttime Light

The Analysis of Urban Ecological Wetland

2012 ◽  
Vol 178-181 ◽  
pp. 300-303
Author(s):  
Zhong Zhong Zeng ◽  
Hai Shan Xia
Keyword(s):  
Urban Landscape ◽  
Landscape Planning ◽  
Wetland Ecology ◽  
Urban Water ◽  
Water Crisis ◽  
Heat Island ◽  
Urban Foundation ◽  
Island Effect ◽  
Green Areas ◽  
Flood Damages

Problems caused by urbanization such as inadequate water content in urban foundation, ecological unbalance in the soil and heat island effect, have become issues that people pay great attention to. Two projects, cited as being successful in integrating urban landscape planning and wetland ecology, are the Water Garden in Portland, USA, and the Living Water Garden in Chengdu, China. Artificial wetland is effective to establish urban ecology. It may not only solve the problem of urban water crisis, but also bring a series of good eco- environmental effects, such as to conserve groundwater, regulate climate, extend green areas, purify air, beautify city and even effectively control flood damages, and etc.

Emergence of opposite trends in daytime and night-time urban heat island intensities in England

2020 ◽  
Author(s):  
Eunice Lo ◽  
Dann Mitchell ◽  
Sylvia Bohnenstengel ◽  
Mat Collins ◽  
Ed Hawkins ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Areas ◽  
Urban Land Use ◽  
Urban Heat Islands ◽  
Urban Heat Island Effect ◽  
Heat Island ◽  
Night Time ◽  
Heat Islands ◽  
Island Effect ◽  
Urban Heat

<p>Urban environments are known to be warmer than their sub-urban or rural surroundings, particularly at night. In summer, urban heat islands exacerbate the occurrence of extreme heat events, posing health risks to urban residents. In the UK where 90% of the population is projected to live in urban areas by 2050, projecting changes in urban heat islands in a warming climate is essential to adaptation and urban planning.</p><p>With the use of the new UK Climate Projections (UKCP18) in which urban land use is constant, I will show that both summer urban and sub-urban temperatures are projected to increase in the 10 most populous built-up areas in England between 1980 and 2080. However, differential warming rates in urban and sub-urban areas, and during day and at night suggest a trend towards a reduced daytime urban heat island effect but an enhanced night-time urban heat island effect. These changes in urban heat islands have implications on thermal comfort and local atmospheric circulations that impact the dispersion of air pollutants. I will further demonstrate that the opposite trends in daytime and night-time urban heat island effects are projected to emerge from current variability in more than half of the studied cities below a global mean warming of 3°C above pre-industrial levels.</p>

Heat Island Effect Aggravates Mortality

2011 ◽  
Author(s):  
Kaufui V. Wong ◽  
Andrew Paddon ◽  
Alfredo Jimenez
Keyword(s):  
Urban Areas ◽  
Air Conditioning ◽  
Heat Waves ◽  
Extreme Heat ◽  
The Body ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Island Effect ◽  
Heat Events ◽  
The U.S

Cases of death during heat waves are most commonly due to respiratory and cardiovascular diseases, with the main contribution from the negative effect of heat on the cardiovascular system. In an attempt to control the body temperature, the body’s natural instinct is to circulate large quantities of blood to the skin. However while trying to protect itself from overheating, the body actually harms itself by inducing extra strain on the heart. This excess strain has the potential to trigger a cardiac event in those with chronic health problems, such as the elderly. Those in the U.S.A. between the ages of 65 and 74 are at a higher risk of mortality during heat waves when they are single, have a history of chronic pulmonary disease, or suffer from a psychiatric disorder. In the older group, 75+, single people are again more vulnerable as well as women. The relationship of mortality and temperature creates a J-shaped function, showing a steeper slope at higher temperatures. Records show that more casualties have resulted from heat waves than hurricanes, floods, and tornadoes together. The significance of this is that the U.S. suffers the highest damage total from natural catastrophes annually. Studies held from 1989–2000 in 50 U.S. cities recorded 1.6% more deaths during cold temperature events, as opposed to a staggering 5.7% increase during heat waves. People are at risk when living in large metropolitan areas, especially those mentioned above, due to the heat island effect. Urban areas suffer heat increases from the combination of global warming effects as well as localized heat island properties. It is flawed to claim that the contribution of anthropogenic heat generation to the heat island effect is small. Analyzing the trend of extreme heat events (EHEs) between 1956 and 2005 showed an increase on average of 0.20 days/year, on a 95% confidence interval with uncertainty of ±0.6. This trend follows the recorded data for 2005 with 10 more heat events per city than in 1956. Compact cities experience an average of 5.6 days of extreme heat conditions annually, compared to that of 14.8 for sprawling cities. The regional climate, city populace, or pace of population growth however does not affect this effect. Statistics from the U.S. Census state that the U.S. population without air conditioning saw a drop of 32% from 1978 to 2005, resting at 15%. Despite the increase in air conditioning use, the positive affects of it may have run their course as a critical point may have been reached. A study done by Kalkstein through 2007 proved that the shielding effects of air conditioning reached their terminal effect in the mid-1990s. Heat-related illnesses and mortality rates have slightly decreased since 1980, regardless of the increase in temperatures. This may be in part to the increase in availability of air conditioning, and other protective measures, to the public. Protective factors have mitigated the danger of heat on those vulnerable to it, however projecting forward the heat increment related to sprawl may exceed physiologic adaptation thresholds.

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