scholarly journals Understanding Urban Growth in Beijing-Tianjin-Hebei Region over the Past 100 Years Using Old Maps and Landsat Data

2021 ◽  
Vol 13 (16) ◽  
pp. 3264 ◽  
Author(s):  
Shuang Li ◽  
Zhongqiu Sun ◽  
Yafei Wang ◽  
Yuxia Wang

Studying urban expansion from a longer-term perspective is of great significance to obtain an in-depth understanding of the process of urbanization. Remote sensing data are mostly selected to investigate the long-term expansion of cities. In this study, we selected the world-class urban agglomeration of Beijing-Tianjin-Hebei (BTH) as the study area, and then discussed how to make full use of multi-source, multi-category, and multi-temporal spatial data (old maps and remote sensing images) to study long-term urbanization. Through this study, we addressed three questions: (1) How much has the urban area in BTH expanded in the past 100 years? (2) How did the urban area expand in the past century? (3) What factors or important historical events have changed the development of cities with different functions? By comprehensively using urban spatial data, such as old maps and remote sensing images, geo-referencing them, and extracting built-up area information, a long-term series of urban built-up areas in the BTH region can be obtained. Results show the following: (1) There was clear evidence of dramatic urban expansion in this area, and the total built-up area had increased by 55.585 times, from 126.181 km2 to 7013.832 km2. (2) Continuous outward expansion has always been the main trend, while the compactness of the built-up land within the city is constantly decreasing and the complexity of the city boundary is increasing. (3) Cities in BTH were mostly formed through the construction of city walls during the Ming and Qing dynasties, and the expansion process was mostly highly related to important political events, traffic development, and other factors. In summary, the BTH area, similarly to China and most regions of the world, has experienced rapid urbanization and the history of such ancient cities should be further preserved with the combined use of old maps.

2021 ◽  
Vol 87 (2) ◽  
pp. 125-132
Author(s):  
Mengjun Kang ◽  
Yunlong Ma ◽  
Qingyun Du ◽  
Min Weng

With the development of urbanization in the world, dealing with the problems caused by urban expansion is becoming more and more important. The data that need to be processed in urbanization studies have increased with the improvement of the spatial and temporal resolution of remote sensing satellites, exerting considerable pressure on traditional software used for landscape index computation. In this article, an improved landscape index-computing algorithm is proposed. Based on CUDA, a pixel-group parallelization strategy is adopted to optimize the algorithm. The results show that the proposed algorithm increases the efficiency by more than a factor of three as the amount of data to be processed increases to 50 million pixels, thus providing a new way to calculate large-scale landscape index values on personal computers to study urbanization.


2020 ◽  
Vol 13 (1) ◽  
pp. 46
Author(s):  
Xinhao Pan ◽  
Yihang Wang ◽  
Zhifeng Liu ◽  
Chunyang He ◽  
Haimeng Liu ◽  
...  

The Tibetan Plateau (TP) is an important area that affects global sustainable development. Quantifying spatiotemporal patterns of urbanization is crucial for maintaining the sustainability on the TP. This study took Xining City, the largest city on the TP, as an example to understand the urban expansion in this region in the past 50 years. We combined the high-resolution spy satellite data and China’s long-term urban land dataset (CULD) to quantify the urban expansion of Xining City. The object-oriented random forest classification was performed to extract urban land from spy satellite data in 1969, and the inter-annual correction was used to combine urban land information from 1969 to 2017. We found that the proposed approach can accurately quantify the urban expansion of Xining City over the past half century with an overall accuracy of 91% and a kappa coefficient of 0.86. Such high accuracy benefits from the fine resolution of spy satellite data and the consistency of CULD. We also found that Xining City experienced accelerated and fragmented urban sprawl to higher altitude areas, as a result of socioeconomic development and topographical limitations. The acceleration of urban expansion was more obvious, and the urban landscape fragmentation was more serious at high altitude areas. Such urban expansion encroached on cropland and grassland, and caused increased risks of landslides and other geological disasters. Therefore, Xining City urgently needs to promote the development of compact cities to control urban sprawl at higher altitude areas and provide a reference for improving urban sustainability across the TP. In this study, we analyzed the urban expansion of Xining city from 1969 to 2017, and provided a reliable way to understand the long-term spatiotemporal urbanization based on remote sensing, which has the potential for wide applications. In addition, the extracted urban information can help to improve the urban sustainability of Xining City and the entire TP.


Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 569
Author(s):  
Jean-Nicolas Tournier ◽  
Joseph Kononchik

The eradication of infectious diseases has been achieved only once in history, in 1980, with smallpox. Since 1988, significant effort has been made to eliminate poliomyelitis viruses, but eradication is still just out of reach. As the goal of viral disease eradication approaches, the ability to recreate historically eradicated viruses using synthetic biology has the potential to jeopardize the long-term sustainability of eradication. However, the emergence of the severe acute respiratory syndrome-coronavirus (SARS-CoV)-2 pandemic has highlighted our ability to swiftly and resolutely respond to a potential outbreak. This virus has been synthetized faster than any other in the past and is resulting in vaccines before most attenuated candidates reach clinical trials. Here, synthetic biology has the opportunity to demonstrate its truest potential to the public and solidify a footing in the world of vaccines.


2021 ◽  
Vol 263 (6) ◽  
pp. 206-214
Author(s):  
David Montes-González ◽  
Juan Miguel Barrigón-Morillas ◽  
Ana Cristina Bejarano-Quintas ◽  
Manuel Parejo-Pizarro ◽  
Guillermo Rey-Gozalo ◽  
...  

The pandemic of coronavirus disease (COVID-19) led to the need for drastic control measures around the world to reduce the impact on the health of the population. The confinement of people in their homes resulted in a significant reduction in human activity at every level (economic, social, industrial, etc.), which was reflected in a decrease in environmental pollution levels. Studying the evolution of parameters, such as the level of environmental noise caused by vehicle traffic in urban environments, makes it possible to assess the impact of this type of measure. This paper presents a case study of the acoustic situation in Cáceres (Spain) during the restriction period by means of long-term acoustic measurements at various points of the city.


Author(s):  
Hario Megatsari ◽  
Ilham Akhsanu Ridlo ◽  
Dian Kusuma

BACKGROUND Indonesian tobacco control initiatives are minimal despite having the second-highest adult male smoking prevalence in the world, with less than 10% of districts/cities banning outdoor tobacco advertisements. This research aimed to provide evidence on the presence of outdoor tobacco advertisements near health facilities in Surabaya where there is no outdoor advertising ban. METHODS Data collection was carried out in Surabaya from October to November 2018. Data of government (public) and private health facilities were obtained from the city health office. Two spatial data analyses were carried out: a buffer analysis near the healthcare facilities and an advertisement hotspot analysis using ArcMap 10.6. RESULTS From 308 tobacco advertisements that were identified, there were billboards (63%), banners (31%), and videoboards (7%). Of 142 public and 1,242 private health facilities in Surabaya, 26% and 31% had advertisements within 300 m and 63% and 70% were within advertisement hotspots, respectively. Furthermore, 5% of advertisements were within 300 m from public health facilities and 21% of them were within 300 m from private health facilities. CONCLUSIONS Outdoor tobacco advertisements were widespread throughout the city, prominently around public and private health facilities.


2020 ◽  
Vol 1 ◽  
pp. 1-15
Author(s):  
Rodrique Kafando ◽  
Rémy Decoupes ◽  
Lucile Sautot ◽  
Maguelonne Teisseire

Abstract. In this paper, we propose a methodology for designing data lake dedicated to Spatial Data and an implementation of this specific framework. Inspired from previous proposals on general data lake Design and based on the Geographic information – Metadata normalization (ISO 19115), the contribution presented in this paper integrates, with the same philosophy, the spatial and thematic dimensions of heterogeneous data (remote sensing images, textual documents and sensor data, etc). To support our proposal, the process has been implemented in a real data project in collaboration with Montpellier Métropole Méditerranée (3M), a metropolis in the South of France. This framework offers a uniform management of the spatial and thematic information embedded in the elements of the data lake.


2021 ◽  
Author(s):  
Mingyuan Zhu ◽  
Zhibao Wang ◽  
Lu Bai ◽  
Jie Zhang ◽  
Jinhua Tao ◽  
...  

2021 ◽  
Author(s):  
Ian McCallum ◽  
Stefan Velev ◽  
Finn Laurien ◽  
Reinhard Mechler ◽  
Adriana Keating ◽  
...  

<p>Communities around the world in flood-prone regions are increasingly aware of the benefits of using spatial data to better understand their predicament. With the advent of web mapping, free and open satellite data and the proliferation of mobile technologies, the possibilities for both understanding and improving community resilience are on the rise.</p><p>Here we present the “Flood Resilience Dashboard”, which is designed to put geo-spatial flood resilience data into the hands of practitioners. The objective is to provide a platform for practitioners in the Zurich Flood Resilience Alliance which gives access to both community resilience data and freely available, peer reviewed flood risk data, which can be used for decision support at scale. This data will include among others the Zurich Flood Resilience Measurement for Communities (FRMC) data, Vulnerability Capacity Assessment (VCA) maps, remote sensing derived information on flooding and other biophysical datasets (e.g. forest cover, water extent), modelled risk information, satellite imagery (e.g. night-time lights), crowdsourced data and more. Using two case studies, we illustrate how the above-mentioned datasets help to better understand community resilience. When co-developed with communities, these examples could potentially be scaled up and applied to similar regions around the world.</p>


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