Be wary of "gentle knife"!Studies have shown that the ground of multiple coastal cities in South Asia and Southeast Asia rapidly settle down

According to the reference news, quoting the US DC's website reported on September 22, scientists said that cities in South Asia and Southeast Asia are falling faster than similar cities in other places. The proper control has exacerbated the risks brought by the rise of the sea level.

It is reported that in the past 20 years, the population of Bangladesh's Grand Port in Bangladesh has increased by more than 120%to 5.2 million. According to the latest research, it is also one of the fastest sinking cities in the world.

This week's research published in the magazine of "Nature · Sustainable Development" found that the ground settlement was particularly fast on the coastal cities based on the coastal cities built on the "flat, low altitude rivers". In these places, the rapid economic growth and urbanization have promoted the mining of groundwater and oil.

Multiple coastal cities ground settlement

Be wary of "gentle knife"

A group of international scientists led by Nanyang University of Science and Technology in Singapore used satellite images taken from 2014 to 2020 to analyze the land settlement of 48 most densely coastal cities worldwide. They found that the medium value of the 48 coastal cities reached 16.2 mm per year.

It is reported that Xie Lier Tai (sound), the main author of the research of Nanyang University of Science and Technology and the main author of the research: "When people take a lot of groundwater, because the water supports the water is less And began to sink, causing the ground to settle. "

This study shows that Indonesia, Myanmar, and India also have some areas with a faster ground settlement.

Emma Hill, a professor of Earth Sciences and one of the reports of Nanyang University of Science and Technology, said: "This research is important because it quantifies the ground settlement in a global way, which can be used to improve the rise of the sea level. evaluation of."

According to the China Science Journal, compared with severe geological disasters such as earthquakes, tsunami, and landslides, the ground settlement is much "mild". Its scale is often represented by millimeters and centimeters. The irreversible harm of cracking, collapse of high -rise buildings, and pouring seawater. Because it is slow, it does not often attract people's attention.

Photo source: Photo Network_501612548

Earlier, a research warning of a UNESCO ground settlement working group warned that by 2040, the ground settlement would threaten nearly 1/5 of the world's population. Related results are published online in "Science".

Jakarta sinks 28 cm each year

Indonesian plan to move capital

According to reference, Jakarta is one of the fastest settlements. After years of rapid growth, congestion and pollution, Jakarta as the Indonesian capital will be replaced by other cities.

It is reported that the architects and urban planners of the United States and Southeast Asia, Ji'an Gao (sound), said: "By 2030, a large part of Jakarta will not be suitable for living. The root cause of the urban ground settlement is Development, plus lack of full planning. "

Gao said that if the city has enough pipelines and municipal water supply, there is no need to fight well and extract groundwater. "These issues are ultimately caused by planning and political issues."

According to the China Science Journal, literature studies have shown that in the past century, the ground sedimentation caused by groundwater depletion in 34 countries has occurred in the past century. But in fact, there are far more than these areas. The study has established a global ground settlement database on the basis of public data from various countries and draws distributed maps. Data show that the coastal drop in the Indonesian capital of Jakarta is very serious, and it falls 28 cm each year. At present, the housing buildings on the beach are already below the sea level and cracking. The government is planning to move the capital to Borneo.

In addition, some Iranian cities are sinking at a rate of 25 cm/year; the land area of ​​1/4 of the Netherlands is lower than the sea level; In a century, from the Central Valley of California to the Atlantic and the Gulf of Mexico, the sedimentation volume dropped by 9 meters.

Edit | Wang Yuelong Gai Yuanyuan

School pair | Sun Zhicheng