One of the most ambitious construction endeavors ever seen continues in China as mountaintops are being flattened and valleys are being filled to create space for new cities.
The Chinese government is looking to move more rural residents to urban areas to develop a more modern economy, according to a recent Associated Press story.
The size and scope of the project is something that has never been seen before, and many questions are being raised about the long-term ramifications.
In the city of Lanzhou, located in the northwestern province of Gansu, 700 mountains are being flattened as part of a massive expansion project called the "Lanzhou New Area." The city is expected to have a population of 100,000 and will lead to an "environmentally sustainable economy based on energy-saving industries," according to state-controlled TV. Projects are also underway in the cities of Chongqing, Shiyan, Yichang, Yan'an and Guizhou.
In a recent report published in the science journal Nature, Chinese researchers Peiyue Li, Hui Qian and Jianhua Wu, all from the School of Environmental Science and Engineering at Chang'an University, said that the project has not been thought through "environmentally, technically or economically."
The report stated that about one-fifth of the Chinese population lives in the mountainous areas of the country, where land development is in "short supply."
Mountaintop flattening is common in the strip mining in parts of the eastern United States, but it is not on the same scope as the building occurring in China. The peaks being flattened can be as high as 150 meters (492 feet).
"Land creation by cutting off hilltops and moving massive quantities of dirt is like performing major surgery on Earth's crust," the research group said.
Air pollution is already a serious concern in China, and this project is continuing to add negative environmental impacts, the researchers said.
In April 2013, air pollution became visible with the project in Lanzhou, and construction was halted. However, due to mounting construction costs to local government officials and contractors, the project was resumed just four weeks later, according to the report in Nature. The report also mentioned that the air in Yan'an becomes brown with dust on windy days because construction crews did not dampen the soil.
The question of land stability is one of the biggest, especially when it comes to how safe it can be for urban development.
Landslides and flooding have been reported in Shiyan due to the changing of hills to plains and waterways have been altered, according to the report.
Brian McGlynn, professor of watershed hydrology and biogeosciences at Duke University expressed similar concern due to the uncertain nature of a project of this magnitude.
McGlynn said the time it will take for the soils being moved into the valleys to become stable isn't clear.
"A high concern is the settling time, or the time it will take for these soils to compact and be technically stable and in order to allow urban construction, I think this is unknown," McGlynn said.
McGlynn said the watershed soils and natural subsurface drainage patterns that have evolved over tens of thousands of years are going to be reset almost instantly.
"We aren't able, at least to my knowledge, to predict what will be the ramifications or what will happen to this system once it's reset and recontoured," he said.
Water flows in rivers and streams could also be significantly altered, plus McGlynn said they could see an increase in sediment from the removed soil.
McGlynn said the disturbance of these soils may lead to a high sediment delivery to the river system and dramatically alter water quality.
The timing of high flows and low flows of rivers remains an open question, McGlynn said.
Without knowing the full effects of this scale of land disturbance, the magnitudes of the floods and severity of the droughts remain uncertain.
As part of their recommendation, the research group called on the Chinese government to accelerate research efforts and proceed with caution on current construction.
McGlynn said he thought that China is moving ahead faster than science on this project.
"That's the experimental portion of this, we'll likely learn some things from this urbanization and flattening of the landscape," he said. "But the dangerous consequences are sort of yet unknown."