We talked about Wushan airport in Chongqing before
It’s not huge in terms of size or area
But the difficulty of construction is daunting for countries around the world
Due to its special geographical location, Chongqing is mostly mountainous and hilly
In order to build the airport, the builders leveled seven mountains
Six valleys were filled and 2,698 acres of land was eventually cleared
There are many geographical environments like Chongqing in China
Chongqing is just cutting mountains to build an airport
And the project we’re going to talk about is even more ambitious
That’s yan ‘an new area
Located in the middle reaches of the Yellow River, yan ‘an city belongs to the hilly and gully region of the loess plateau
The terrain is high in the northwest and low in the southeast, with an average elevation of about 1200 meters
Mountains and hills account for 72 percent of the total area
The city of 36 square kilometers holds a population of 500,000
The population density is close to Beijing and Shanghai
At present, the main buildings in yan ‘an are located on both sides of the river
Seen as a straight line from the satellite map, it is also known as a first-tier city
The yanan municipal government decided to build a new city
Yan ‘an new area is planned to be divided into three areas, which will be cut through mountains and filled with ditches
Finally, 78.5 square kilometers of new urban construction area was excavated
Before the construction of the new town, the builders made a detailed geological survey
It has cut 33 mountains, which is one of the largest geotechnical projects in the world
According to the plan, the three areas are north district and phoenix district
The north area covers an area of 38 square kilometers
Mainly in the administrative center, business center, residential areas
The southern district covers an area of 32 square kilometers
Mainly to the district - level administrative center, experience area - based
Phoenix town covers an area of 3.1 square kilometers, mainly in the tourism industry
In addition to the administrative center planning, the main purpose of the new town is the population
A total of 100,000 people live in caves on the mountain in the urban area of yan ‘an
When the new town is built, the first plan is to move the 100,000 people down the mountain
All moved to the new town
The entire new town is expected to have around 400,000 residents
Will greatly relieve the population density pressure in the old city
As early as 2012, the first phase of the north district of yan ‘an new area was started
The construction area is 10.5 square kilometers, with a total investment of 5.3 billion yuan
From the map of Google, we can see that the first phase of the project has been almost completed
But the southern area has not yet started construction, mainly ecological environmental problems
Yan ‘an cut mountains and filled ditches on a large scale
What is the impact on the ecological environment?
In the early stage, the yan ‘an municipal government organized over 30 experts to carry out 7 seminars
After many arguments, it is considered that this project can be implemented
Future foundation stability is considered
All the tall buildings will be built on the mountain
The area created by the trench will be mainly used for greening
Construction is not considered for the time being
The geology of the area formed by landfilling
It takes a period for the geology to stabilize
As short as three to five years, as long as ten years
Except for building tall buildings on mountains
There will also be height controls on the buildings
Generally, around 50 or 60 meters, the highest floor in the business district will not exceed 100 meters
In addition, after cutting mountains and filling ditches, the original natural drainage ditch will be artificially changed
If the groundwater is not effectively discharged, it can lead to geological collapse or subsidence
The permanent blind ditch was used in the construction of yan ‘an new area
To empty the groundwater in the mountains
In this way, the overall subsidence caused by groundwater erosion can be avoided
Because mountain environment changes greatly, still can cause lack of water problem
The average annual rainfall of the river in yan ‘an city is small and the evaporation is large
In the future, yan ‘an new town can not meet the demand only by collecting water in the region
Fortunately, there is the Yellow River nearby, for which yan ‘an city has developed a water diversion plan
It draws 91.8 million cubic meters of water from the Yellow River every year
In addition to the new city water
It can also provide water security for factories and industrial parks
But such a massive scale of mountain cutting and ditching
Construction costs are out of control
According to a rough estimation, the investment of the whole new town will reach 50 to 60 billion
This is just the cost of cutting mountains and filling ditches after the construction land is filled
Also consider transportation, infrastructure, electricity, water, heating and so on
The total cost is expected to be only $100 billion
This is equivalent to two-thirds of the city’s GDP in 2018
At present, the new town adopts the debt financing scheme
No matter in the construction cost or ecological environment
Yan ‘an new city is not the best choice
But for yan ‘an, with its ravines, this is the only way
The area of the old city is only a few hundred kilometers
Even the traffic problem can’t be solved
And if yan ‘an wants to develop, want to carry out the urbanization process
It is imperative to cut mountains and fill ditches
Just like the Hong Kong-Zhuhai-Macao bridge in the Guangdong-Hong Kong-Macao greater bay area
Do you support such a project?