中国收缩城市研究网络

Shrinking City Research Network of China (SCRNC)

Members

Researchers: Ying Long, Xun Li, Kang Wu, Dongfeng Yang, Wei Zhu, Xueliang Zhang, Zhigang Li, Gonghao Cui, He Huang, Jiangping Zhou, Hong Leng, Peng jiang, Helin Liu, Xingjian Liu, Xinyue Ye, Kai Zhou, He Li, Tingting Chen, Xiaodi Zheng, Yuanjing Zhang, Shuqi Gao, Xiaoxiang Yi, Yue Wang, Zhichong Zou, Xiangfeng Meng, Quanchuan Fu, Pingjun Sun (按参加顺序:龙瀛,李郇,吴康,杨东峰,朱玮,张学良,李志刚,崔功豪,黄鹤,周江评,冷红,姜鹏,刘合林,刘行健,叶信岳,周恺,李鹤,陈婷婷,郑晓笛,张远景,高舒琦, 衣霄翔,王月,邹志翀,孟祥凤,付泉川,孙平军)

Volunteers: Biao Tong, Nawei Wu, Yang Ju, Jie Zhang, Yiyun Sun.

Calling for more volunteers. Please address your CV and interest to Dr Long via ylong@tsinghua.edu.cn (志愿者召集中)

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This is a paper prepared by some of the members of the network.
吴康等 2023 自然资源学报_资源型城市.pdf
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Background

城市人口的收缩由来已久,德国政府资助项目(Shrinking Cities)已经证实,全球范围内人口超过100万的450个城市地区,总体上失去了其城市人口的十分之一。德国学者近几年进行了开创性的探讨(发表在Environment and Planning A/B上),以居住人口作为评价指标已成为共识。总体上,国际上发生城市收缩的原因,主要在于,(1)全球化背景下从制造业到服务业的经济转型,以及由此造成的劳动力结构性失业和产业资本外流;(2)其他影响因素还包括郊区化、战争、自然或人为灾害、老龄化或低生育率,以及东欧国家社会主义制度的瓦解等。

在中国,收缩现象还为增长的主流所忽视,规划实践上人口必须增长的桎梏观念还鲜有突破。事实上,全球金融危机引发的出口加工工业的衰退和国内劳动力刘易斯拐点的到来,都使中国城市增长的条件发生变化。龙瀛和李郇博士2014年开始关注收缩城市的研究,例如龙瀛博士从三个尺度(小区、乡镇和城市)对中国局部收缩现象进行研究,李郇针对珠三角进行了深入的探索性研究。国内关注收缩城市研究的学者,于2014年11月共同发起了“中国收缩城市研究网络”(http://www.beijingcitylab.com/projects-1/15-shrinking-cities/),将持续跟踪收缩城市方面的国际研究并开展国内的理论和实证研究工作。

Many cities across particular areas in Europe and North America have a dwindling population, emerging vacant spaces, and the underuse of existing urban infrastructure (Haase et al., 2014). As one of the more prosperous urbanized countries in the world, China has witnessed an unprecedented active stage of urban expansion (see the Beijing City Lab Ranking 8 for details, http://www.beijingcitylab.com/ranking/), which also attracted extensive attention from academics (Deng et al., 2010).

Our previous study on mushing Jiedaos (the basic administrative unit of a city proper) indicates that urbanization in China often involves a significant political dimension. Largely rural settlements (eg, Zhen) could be accorded with the city status (eg, Jiedao) overnight by administrative power, which further accelerates the urban process (Wu et al., 2015).

Meanwhile, some large cities and inshore developed cities in East China have attracted huge numbers of migrants from rural areas and small cities during the last ten years. Vacant villages have been widely reported in the context of China (Long et al., 2012), while we observe a shrinking phenomenon at township and city levels.

For all the townships in mainland China, we estimated their population (residents not Hukou) based on the Population Censuses of China in 2000 and 2010, respectively. We found that 19,882 among all 39,007 townships were losing their population during 2000-2010, and the total area was 3.24 million km2, which covered almost about one third territories of China (Figure 1). Those shrinking townships are distributed in both rural and urban areas. Among them are 1,147 urban townships with a total area of 47,420 km2 in 367 cities.

Besides shrinking townships observed, we further identify 180 shrinking cities in China including one provincial capital city Urumqi, 40 prefectural-level cities and 139 county-level cities (Figure 1). In addition, we use a cartogram to reveal population density in 2010 at the prefectural level, based on which shrinking prefectures are mapped (Figure 2).

More work is needed to understand these shrinking localities, the reasons behind the population falls, and possible policy tools. Both decision makers and city planners are accustomed to the urban growth and population increasing in China. We hope that these featured graphics will inform them of our findings. In addition, we have established the Chinese shrinking city research network (http://www.beijingcitylab.com/projects-1/15-shrinking-cities/) for exploring this important issue via proposing necessary planning rules for shrinking cities.

Decreased population density at the township and city levels

Related documents

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Shrinking cities in a rapidly urbanizing China
Published in Environment and Planning A
Long and Wu 2016 EPA_Shrinking.pdf
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A Chinese paper Dr Ying Long published on the debate between urban expansion and population shrinkage
龙瀛 2015 探索与争鸣_扩张与收缩.pdf
Adobe Acrobat Document 873.0 KB
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如何拯救收缩的城市_英国老工业城市转型经验及启示_杨东峰.pdf
Adobe Acrobat Document 2.8 MB
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精明收缩:应对城市衰退的规划策略及其在美国的实践_黄鹤.pdf
Adobe Acrobat Document 2.7 MB
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Conceptualizing urban shrinkage.pdf
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By The Economist
Rus in urbe redux _ The Economist.pdf
Adobe Acrobat Document 1.3 MB
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Spatial metrics to study urban patterns
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Other papers/books

Shrinking Cities: International Perspectives and Policy Implications (Google eBook)

Shrinking Cities: A Global Perspective (Google eBook)

Shrinking City Studio @ MIT


Media coverage

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龙瀛 2019 北京规划建设_收缩城市采访.pdf
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龙瀛 2019 城市中国_收缩城市采访.pdf
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2019.03 零点财经论坛:中国近千城镇人口萎缩,未来会不会出现“铁锈带”荒凉
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2018.03 Global Times:Smaller Chinese cit
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2019.03 EDGY:Data Shows One Third of Chi
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2019.03 The Greg Zone:China’s shrinking
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2019.03 Inkstone index: China’s shrinkin
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2019.03 智谷趋势:中国城市进入急速收缩的时代,一些注定将走向破败.pdf
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2019.03 新京报:“人才集聚”与“城市收缩”塑造中国城市未来格局.pdf
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2019.04 功夫财经:三四线,危矣!.pdf
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2019.04 21世纪经济导报:当城市不再长大:发改委文件首提收缩型城市,这意
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2019.04 《联合早报》:发改委宣布城镇落户限制大松绑 学者:全民有更公平发
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2019.04 上海金融与法律研究院:收缩城市,连抢人的资格都没有?.pdf
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2019.04 城市数据团:收缩城市:有抢人的,就有“丢人”的.pdf
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一席的PPT(Slides of Dr Ying LONG's Yixi Talk)
龙瀛的一席talk v3.pdf
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Our study has been reported by National Geographic
美国国家地理杂志NGM对中国收缩城市的报道:How millennials gr
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Qiqihar Case Study

Analysis on Variation of Quality of Street Space in Shrinking Cities Based on Dynamic Street View Pictures Recognition: A Case of Qiqihar

As the focus of urban planning in China converts from incremental planning to stock-based planning, researches concerning shrinking cities become increasingly important. Street being one of the basic elements of cities, the changes of spatial quality of it are essential to the evaluation of the changes of shrinking cities. This study uses street views from the Tencent Maps to evaluate the changes of quality of street space in the central districts of Qiqihar from 2013 to 2015. The research reveals that the quality of street space of Qiqihar is getting better while the rapid change of commercial real estate under residential buildings suggests a decline in economy. Based on this finding, the“Population-Economy-Space Decline Lagging Phenomenon”is proposed to illustrate the change mode of population, economy and spatial quality during the shrinking process of cities.

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李智和龙瀛 2018 城市建筑_齐齐哈尔空间变化.pdf
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Shrinking Cities in China: The Other Facet of Urbanization

We have published a Springer book entitled "Shrinking Cities in China: The Other Facet of Urbanization". More information is available online at Springer (https://www.springer.com/us/book/9789811326455).

This book offers an essential introduction to the phenomenon of shrinking cities in China, highlighting several case studies, qualitative and quantitative methods, and planning responses. As an emerging topic in urbanizing China, cities experiencing population loss have begun attracting increasing attention. All chapters of the book were contributed by leading researchers on the subject in China. Richly illustrated with photographs for a better visual understanding of the topic, the book will benefit a broad readership, ranging from researchers and students of urban planning, urban geography, urban economics, urban sociology and urban design, to practitioners in the areas of urban planning and design.

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Long and Gao 2019 Springer_ShrinkingCiti
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Identifying Shrinking Cities with NPP-VIIRS Nightlight Data in China

Although there has been a rapid urbanization in China since the 1980s, the simultaneous urban shrinkage phenomenon has existed for a long time. The study of shrinking cities is particularly important for China as the current urban development has changed from physical expansion to built-up area improvement. After redefining what constitutes a city (what we term a natural city), we compared the adjusted nightlight intensity of National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) data between 2013 and 2016 to accurately identify shrinking cities throughout China. The results indicate that there are 2,862 redefined natural cities in China and that the total area reaches 53,275 km2, about 0.5% of the national territory. Based on this, we identified 798 shrinking cities with a total area of 13,839 km . After analyzing the relative position of shrinking cities and internal shrinking pixels in the geometric space, the morphological characteristics of shrinking cities were systematically classified into six patterns. The majority of shrinking cities belong to scatter shrinkage, central shrinkage, and local shrinkage; only 5% are complete shrinkage; the rest are unilateral shrinkage and peripheral shrinkage. In addition, six shrinkage causes were quantitatively classified and summarized by referring to multiple-source urban data and municipal yearbooks. To enrich the methodological system for urban shrinkage, the research provides a reminder of the need to consider the other side of urbanization (i.e., dissolution of social networks) and proposes appropriate strategies and policies to address shrinkage issues.

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Jiang et al 2020 JUPD_ShrinkingCitiesIde
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We are sharing the GIS data (shrinking city distribution) derived from this paper here.
JUPD_Data.zip
Compressed Archive in ZIP Format 22.9 MB

Shrinking cities on the globe: Evidence from LandScan 2000–2019

Shrinking cities have spread across the globe in recent decades, characterizing signifificant population loss, economic decline, and decay in spatial quality. To maintain global economic prosperity in the context of urban shrinkage and support decision making in the direction, it is necessary to accurately identify shrinking cities on a global scale. We utilize redefifined natural city boundaries and the LandScan dataset to identify and map shrinking cities experiencing population loss on the globe. As a result, we have identifified 5004 shrinking cities worldwide, with a total area of 126,930 km2 during 2000–2019. The ratio of which in number and in area is 27% and 22%, respectively. The shrinking cities are clustered and mainly located in Europe, Eastern Asia, and northeastern United States. There are 41 countries with more than 20 shrinking cities on the globe. The number of shrinking cities in China reached 679, which is the most. Among the 41 countries, the median value of the natural cities’ shrinking ratios of Iraq, Iran, Austria, South Africa, Russia, Georgia, and Belarus is >50%, indicating that the urban population loss in these countries is relatively serious. Our fifindings can be used to inform decision makers and urban planners to adjust the “growth-oriented” planning paradigm and adopt precise strategies, to form a healthier urban development.
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Meng et al 2021 EPA_GlobalShrinking.pdf
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We are sharing the ShapeFiles for all natural cities and their population in 2000 and 2019
EPA_DATA_GLOBE_SCs.zip
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Classification of shrinking cities in China using Baidu big data

In the context of rapid urbanization, shrinking cities cannot be ignored. The classification of shrinking cities according to the patterns of urban population changes is the key to reveal the "hollow" and changing characteristics of the population. Researchers classified the shrinking cities in Western developed countries as "perforated", "doughnut" and "peripheral" types. However, there is a lack of evidence showing the types of shrinking cities in China. This paper takes the redefined physical cities in China (excluding Hong Kong, Macao and Taiwan) as the study area, and employs Baidu Huiyan's 200 m × 200 m grid cell permanent population data from November 2016 to November 2018 to identify different types of shrinking cities in the country. Our results show that 1506 physical cities have experienced a population reduction between 2016 and 2018, accounting for 49.8% of the total number of physical cities (3022). Furthermore, in order to accurately identify the types of shrinking cities, 126 densely populated and severely shrinking cities during the study period were selected as the research samples, mainly located to north of the Qinling Mountains and Huaihe River of China. Our analysis shows that the shrinking types of the sample cities can be classified into five categories: "perforated", "complete", "local", "doughnut", and "peripheral". The number of cities with perforated shrinkage is the largest, which numbered 47 (37.3% of the sample cities), most of which are found in Heilongjiang Province, Inner Mongolia Autonomous Region and Gansu Province. Complete shrinkage ranks the second, including 33 cities, which accounts for 26.2% of the samples, and mainly distributed in Gansu and Shaanxi provinces. The numbers of shrinking cities with local, doughnut and peripheral types are 25, 18 and 3, respectively. These cities are mainly distributed in Heilongjiang and Inner Mongolia. This is because the governments paid more attention to the development speed over quality during the first half of China's urbanization process, and adopted a growth- oriented urban planning strategy. Traditional industries declined due to resource depletion or economic transformation, and the transfer of industries under active government adjustment, all of which contribute to the

emergence of perforated shrinkage. This study could provide scientific evidence for micro management of urban development, optimization of land use pattern, improvement of urban livability, and conduct of urban planning and design in the context of urban shrinkage.

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孟祥凤等 2021 地理学报_收缩城市.pdf
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Shrinking cities in China: Evidence from the latest two population censuses 2010–2020

As the world’s largest developing country, most Chinese cities are experiencing both population shrinkage and spatial expansion in the context of rapid urbanisation. To address the negative impacts of urban shrinkage in a targeted manner, it is necessary to accurately identify shrinking cities in China. In this study, we utilise the sixth and latest seventh population census data to identify and map shrinking cities in China that are experiencing population loss between 2010 and 2020. As a result, we identified 1507 shrinking districts and counties (52% of all 2896 districts and counties in China), with a total area of 4.4 million km2, covering almost 46% of China’s territory. In addition, we further found that from 2010 to 2020, there are 266 shrinking cities in China, an increase of 86 (12%) compared with 2000–2010. This indicates that the situation of shrinking cities in China has become more critical. From the perspective of spatial distribution, Chinese shrinking cities are clustered, mainly in the northeast and central regions.We also plot the proportion of shrinkage in a deformed form to reveal which prefecture-level cities are losing population from 2010 to 2020. Our findings provide policymakers and urban planners with a reference and warning that measures should be taken to adjust the growth-oriented planning paradigm to reverse the negative impact of population loss on urban development.
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Meng and Long 2022 EPA_ShrinkingCities.p
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We are also sharing the GIS data we produced in this paper
EPA_DATA_CHINA_SCs.zip
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Satellite monitoring of shrinking cities on the globe and containment solutions

Shrinking cities are often neglected in the context of global urbanization, the tip of the iceberg that was driven by underlying complex sets of causes. Therefore, it is urgent and crucial to investigate the invisible aspects of global urbanization propelling specific challenges to attain Sustainable Development Goal 11 (SDG 11) related to sustainable cities and communities. Here, we identify shrinking cities in 1992–2000, 2000–2012, and 2013–2018 and predict them in 2018–2050, using nighttime light images and redefifined natural city boundaries. The proportion of shrinking cities increased from 9% to 16 and 25%. Looking ahead, there will be 7,166 predicted shrinking cities in 2050, accounting for 37% of all cities. In this context, synergistic efforts like regreening vacant lands and constructing

compact cities would help achieve SDG 11 in consideration of the new urban shrinking landscape with multisource data like CO2 emissions and points of interests (POIs).

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Zhai et al 2022 iScience_ShrinkingCities
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iSciencePaperDataResults.zip
Compressed Archive in ZIP Format 65.5 MB

We are at UABB 2022 Shenzhen

You can click the image above or the LINK for more information regarding our UABB work, including a well-prepared video.

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ShrinkingCitiesUABB2022.pdf
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DetailedDescriptions2ShrinkingCitiesUABB
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We are at 18th International Architecture Exhibition La Biennale di Venezia

More details are available online at https://mp.weixin.qq.com/s/EJdROT3QtfEhfmv_JF5rMQ

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威尼斯建筑双年展中国国家馆展览 | 技术变革下的中国收缩城市.pdf
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Future shrinking cities on the globe: A projection map for 2020–2100 based on global gridded population dataset

Shrinking cities have become increasingly prevalent worldwide due to various factors, which pose serious challenges to affected areas in terms of population decline, economic decline, and spatial deterioration. While existing research studies have focused on identifying shrinking cities, there is a need for global projections to mitigate uncertainties in their growth trajectories. Spatially explicit population grids offer a new approach to identifying potentially shrinking cities with suffificient spatial resolution. By utilizing a global gridded population dataset from 2020 to 2100 under the SSP2 (Middle of the Road) scenario, we produce a global projection map for future shrinking cities. Among the total 19,024 natural cities, 9682 cities (50.9%) will face population decline and 1751 cities (9.2%) may lose more than half population by 2100. Cities in East Asia and East Europe may face serious population decline.

Global gridded population dataset in 2020 and 2100 under SSP2 can be open accessed at

https://doi.org/10.6084/m9.fifigshare.19608594.v2. NC boundaries in 2020 can be accessed at https://doi.pangaea.de/10.1594/PANGAEA.905890 or http://www.geosimulation.cn/GlobalSSPsUrbanProduct.html.

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Wang and Long 2023 EPB_GlobalSCs.pdf
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EPB_DATA_Global_SCs.zip
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Characteristics of "resident population in physical urban area" in identifying shrinking cities: An examination based on literature review and multi-source data

In the context of China reaching its population peak and moving into a new stage of urbanization, the study of shrinking cities has increasingly captured the attention of the academic community. This paper undertakes a thorough systematic review of the literature and empirical studies, focusing particularly on the methodologies used for identifying shrinking cities in China. One key method discussed is from the study which utilized "resident population in physical urban area" data to identify shrinking cities. To enhance the precision of this methodology, our study conducted extensive geocoding of all village- level administrative units across China. Using urban-rural classification codes, we approximated the boundaries of "urban areas" as referred to "resident population in physical urban area" data. This allowed for a more nuanced comparison of these theoretically derived boundaries with those observed through remote sensing technologies and actual boundaries of natural cities. This comparison sheds light on the specific characteristics of defining urban areas solely based on this data. Further exploring the implications of these findings, our research utilized multi- source population data to identify the number and proportion of shrinking cities in China between 2010 and 2020. The study uncovered some insights: Firstly, the urban- rural classification codes used in population statistics tend to merge numerous natural cities into a single urban unit. This aggregation makes it challenging to analyze population changes within individual natural cities. Secondly, the "resident population in physical urban area" data is not suitable to accurately reflect the population dynamics in nearly a thousand county- level small and medium-sized towns, which are crucial to understanding the broader urbanization trends. Due to these characteristics, the estimations of shrinking city numbers and proportions as defined by this data require further discussion. By applying the boundaries of 2444 natural cities in China and integrating multiple data sources like WorldPop and LandScan, our research found that the proportion of shrinking cities lies between 26.7% and 31.3%. This study underscores the importance of utilizing a diverse array of data sources and analytical methods to more accurately identify and understand the phenomenon of urban shrinkage in China. Such a comprehensive approach helps mitigate the uncertainties that single data sources may introduce, providing a more robust framework for policymakers and urban planners addressing the challenges of urban decline.
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王新宇和龙瀛 2024 地理研究_收缩城市识别.pdf
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IdentificationResults.zip
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