近期，国际学术期刊《SCIENCE》发表名为《A national-scale assessment of land subsidence in China’s major cities》的研究论文，论文对全国82个中大型城市的地面沉降进行了评估。研究发现，这些城市的年平均沉降速度快于3毫米/年的面积比为44.7%，其中快于10毫米/年的面积比为15.8%。
城市沉降的说法是否危言耸听？
让我们一起来了解城市为何会出现沉降现象？
以及城市沉降现象会带来哪些危害？
Source：Science
今天的外刊选自Scitechdaily，共计708词，预计阅读时间7分钟。
通过这次的外刊，你将收获：
○关于沿海城市沉降问题的描述
○长难句的拆解
希望你在阅读全文后能够回答以下问题：
○文中哪些城市的沉降问题比较严重？
○城市沉降会带来哪些危害？
外刊解析
Submerging Skylines: Major East Coast Cities Including NYC and DC Rapidly Sinking
U.S. Atlantic coast cities are sinking faster than the global sea level is rising, posing risks to infrastructure in densely populated areas like New York City and Baltimore.Virginia Tech and USGS studies highlight the urgency of addressing this issue.
Major cities on the U.S. Atlantic coast are sinking, in some cases as much as 5 millimeters per year – a decline at the ocean’s edge that well outpaces global sea level rise, confirms new research from Virginia Tech and the U.S. Geological Survey.
High-Risk Urban Areas
Particularly hard-hit population centers such as New York City and Long Island, Baltimore, and Virginia Beach and Norfolk are seeing areas of rapid “subsidence,” or sinking land, alongside more slowly sinking or relatively stable ground, increasing the risk to roadways, runways, building foundations, rail lines, and pipelines, according to a study published on January 2 in the Proceedings of the National Academies of Sciences.
Expert Insights on Infrastructure Impact
“Continuous unmitigated subsidence on the U.S. East Coast should cause concern,” said lead author Leonard Ohenhen, a graduate student working with Associate Professor Manoochehr Shirzaei at Virginia Tech’s Earth Observation and Innovation Lab. “This is particularly in areas with a high population and property density and a historical complacency toward infrastructure maintenance.”
Source：Pixabay
Innovative Mapping Techniques and Findings
Shirzaei and his research team pulled together a vast collection of data points measured by space-based radar satellites and used this highly accurate information to build digital terrain maps that show exactly where sinking landscapes present risks to the health of vital infrastructure. Using the publicly available satellite imagery, Shirzaei and Ohenhen measured millions of occurrences of land subsidence spanning multiple years. They then created some of the world’s first high-resolution depictions of the land subsidence.
These groundbreaking new maps show that a large area of the East Coast is sinking at least 2 mm per year, with several areas along the mid-Atlantic coast of up to 3,700 square kilometers, or more than 1,400 square miles, sinking more than 5 mm per year, more than the current 4 mm per year global rate of sea level rise.
Source：Pixabay
Widespread Implications of Subsidence
“We measured subsidence rates of 2 mm per year affecting more than 2 million people and 800,000 properties on the East Coast,” Shirzaei said. “We know to some extent that the land is sinking. Through this study, we highlight that sinking of the land is not an intangible threat. It affects you and I and everyone, it may be gradual, but the impacts are real.”
In several cities along the East Coast, multiple critical infrastructures such as roads, railways, airports, and levees are affected by differing subsidence rates.
“Here, the problem is not just that the land is sinking. The problem is that the hotspots of sinking land intersect directly with population and infrastructure hubs,” said Ohenhen. “For example, significant areas of critical infrastructure in New York, including JFK and LaGuardia airports and its runways, along with the railway systems, are affected by subsidence rates exceeding 2 mm per year. The effects of these right now and into the future are potential damage to infrastructure and increased flood risks.”
The Intersection of Subsidence and Infrastructure
The new findings appear in the open access journal PNAS Nexus. In the work “Slowly but surely: Exposure of communities and infrastructure to subsidence on the US east coast,” Virginia Tech and U.S. Geological Survey (USGS) scientists measured how much the land along the East Coast has sunk and which areas, populations, and critical infrastructure within 100 km of the coast are at risk of land subsidence. Subsidence can undermine building foundations; damage roads, gas, and water lines; cause building collapse; and exacerbate coastal flooding – especially when paired with sea level rise caused by climate change.
“This information is needed. No one else is providing it,” said Patrick Barnard, a research geologist with the USGS and co-author of the study. “Shirzaei and his Virginia Tech team stepped into that niche with his technical expertise and is providing something extremely valuable.”
Source：Pixabay
Source: Scitechdaily
Author: Virginia Tech
Date: January 5, 2024
生词拓展：
1. submerge
英音/səbˈmɜːdʒ/ 美音/səbˈmɝːdʒ/
[N] To go below or make something go below the surface of the sea or a river or lake. （使）潜入水中，（使）没入水中；浸没
例句：
The submarine submerged when enemy planes were sighted.
潜艇发现敌机后马上下潜。
2. subsidence
英音/ˈsʌb.sɪ.dəns/ 美音/ˈsʌb.sə.dəns/
[N] The process by which land or buildings sink to a lower level. （地面或建筑物的）下沉，沉降
例句：
The building had to be demolished because of subsidence.
这栋大楼因为沉降的原因必须拆除。
3. unmitigated
英音/ʌnˈmɪt.ɪ.ɡeɪ.tɪd/ 美音/ʌnˈmɪt̬.ə.ɡeɪ.t̬ɪd/
[N] Complete, often describing something bad or unsuccessful that has no good or positive points. （常指坏事或不成功的事）完全的，彻底的，十足的
例句：
The whole venture has been an unmitigated disaster.
整个经营项目彻底失败了。
4. terrain
英音/təˈreɪn/ 美音/təˈreɪn/
[N] An area of land, when considering its natural features. 地形，地势;地带
例句：
The car handles particularly well on rough terrain.
这种汽车特别适宜在崎岖不平的地带行驶。
5. occurrences
英音/əˈkʌr.əns/ 美音/əˈkɝː.əns/
[N] Something that happens. 发生的事；事件；遭遇
例句：
Street-fights are an everyday occurrence in this area of the city.
在该市的这一地区，街头斗殴每天都会发生。
6. exacerbate
英音/ɪɡˈzæs.ə.beɪt/ 美音/ɪɡˈzæs.ɚ.beɪt/
[N] To make something that is already bad even worse. 使恶化；使加重；使加剧
例句：
This attack will exacerbate the already tense relations between the two communities.
这次袭击将使两个团体间已经紧张的关系更加恶化。
知识卡：
地面沉降
地面沉降又称为地面下沉或地陷。它是在人类工程经济活动影响下，由于地下松散地层固结压缩，导致地壳表面标高降低的一种局部的下降运动（或工程地质现象）。2021年1月，一项由联合国教科文组织地面沉降工作组组织的研究警告说，到2040年，地面沉降将威胁全球近1/5的人口。相关成果在线发表于《科学》。
地面沉降是自然因素和人为因素综合作用下形成的地面标高损失。自然因素包括构造下沉、地震、火山活动、气候变化、地应力变化及土体自然固结等。人为因素主要包括开发利用地下流体资源（地下水、石油、天然气等）、开采固体矿产、岩溶塌陷、软土地区与工程建设有关的固结沉降等。
地面沉降的危害主要有：(1)毁坏建筑物和生产设施；(2)不利于建设事业和资源开发。发生地面沉降的地区属于地层不稳定的地带，在进行城市建设和资源开发时，需要更多的建设投资，而且生产能力也受到限制；(3)造成海水倒灌。地面沉降区多出现在沿海地带。地面沉降到接近海面时，会发生海水倒灌，使土壤和地下水盐碱化。对地面沉降的预防主要是针对地面沉降的不同原因而采取相应的工程措施。
Source: Shutterstock
重难点解析：
1. U.S. Atlantic coast cities are sinking faster than the global sea level is rising, posing risks to infrastructure in densely populated areas like New York City and Baltimore.
译文：
美国大西洋沿岸城市的下沉速度超过了全球海平面的上升速度，给纽约市和巴尔的摩等人口稠密地区的基础设施带来了风险。
解析：
主语是“U.S. Atlantic coast cities”，“are sinking”是谓语，“posing risks to infrastructure in densely populated areas like New York City and Baltimore”使用非谓语形式作为结果状语，说明是大西洋沿岸城市下沉所导致的结果。其中“pose risk to”表示造成风险，另外“densely”作为副词，常常用来形容某物在数量、程度或分布上的密集。比如densely populated（人口众多）, densely forested（林木茂密）, densely packed（紧密排列）, densely urbanized（城市化密集）等。
2. Major cities on the U.S. Atlantic coast are sinking, in some cases as much as 5 millimeters per year – a decline at the ocean’s edge that well outpaces global sea level rise, confirms new research from Virginia Tech and the U.S. Geological Survey.
译文：
弗吉尼亚理工学院和美国地质调查局的新研究证实，美国大西洋沿岸的主要城市正在下沉，在某些情况下，每年下沉多达5毫米——这种在海洋边缘的下降速度远远超过全球海平面的上升速度。
解析：
“new research”是主语，“confirms”是谓语，“Major cities on the U.S. Atlantic coast are sinking, in some cases as much as 5 millimeters per year”作为“confirms”的宾语，说明“哪些事实被证实”。“a decline”作为先行词，引导“at the ocean’s edge”介词短语作定语和“that well outpaces global sea level rise”定语从句。“in some cases”作为插入语，对主句进行补充说明，表示“在某些情况下”。
3. Shirzaei and his research team pulled together a vast collection of data points measured by space-based radar satellites and used this highly accurate information to build digital terrain maps that show exactly where sinking landscapes present risks to the health of vital infrastructure.
译文：
Shirzaei及其研究团队协力收集了大量由空间雷达卫星测量的数据点，并利用这些高度准确的信息制作了数字地形图，展示了哪些沉降的地形对关键基础设施的整体状况构成风险。
解析：
“Shirzaei and his research team”是主语部分，“pulled together”和“used”作为两个并列的动词，表示“收集数据”和“使用数据”这两个动作，“measured by space-based radar satellites”是过去分词作定语，修饰“a vast collection of data points”，“to build digital terrain maps”是动词不定式作目的状语。“that show exactly where sinking landscapes present risks to the health of vital infrastructure”是定语从句，修饰先行词“maps”。“pull together”指齐心协力，通力合作。“terrain”指地形，地势，地带。ter-这个前缀通常表示“地、土、领域”等含义，例如，territory（领土）、terrain（地貌）、subterranean（地下的）、territorial（领土的，领地的）。
今天的外刊内容到这里就结束了~
面对城市沉降这一挑战，我们必须提高警惕，科学的规划城市建设，合理的管理地下资源，秉承可持续的发展观。
守护脚下的寸寸土地，就是保护我们的家园。
喜欢"有译思"外刊精读栏目的小伙伴可以在下周同一时间继续关注我们，下周见！
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