China's practice of bulldozing the tops of mountains to make way for new cities has been condemned by Chinese scientists writing in the journal Nature.

Satellite images of western Shiyan, China, in 2010 (left) and 2012 (right) after several peaks have been flattened.

Cities which have been constructed in this fashion include Chongqing, Shiyan, Yichang, Lanzhou and Yan'an. In the latter case, in Shaanxi province, in a project commencing in April 2012, the city's current area is to be doubled by creating 78.5 km² of flat ground in this fashion. Overall, tens of square kilometres of land have been created this way.

But the article's authors, Peiyue Li, Hui Qian and Jianhua Wu, from the School of Environmental Science and Engineering at Chang'an University, argue that the consequences of these unprecedented programs have not been properly considered from either an environmental, technical or economic vantage point.

Unbelievably, the policymakers have not conducted cost-benefit analysises or environmental assessments, and many square miles of valuable agricultural land and biodiverse habitats have been lost. There is also, the authors say, a risk of landslides, earthquake and silting up of rivers.

There is an old Chinese fable, called 'The Foolish Old Man who Removed the Mountains', in which a 90-year-old man convinces his young neighbour that he can remove, stone by stone, two mountains that block the way from his house. With the help of deities the man succeeds, and the fable is familiar to all Chinese people as an allegory for perseverance.

But the authors say that "in our view, China should heed the story's title: Earth-moving on this scale without scientific support is folly".

Air and water pollution, soil erosion and substance are already consequences of these activities.

• At the city of Shiyan, which is close to the headwaters of the South-North Water Transfer Project, which is diverging water from rivers through canals in southern China to Beijing and the North, the alteration of hills to create planes has caused landslides, flooding and altered watercourses.
• Around the city of Yan'an the air is thick with brown dust blown by winds. Forests and vegetation on hills adding gullies are stripped ahead of demolition and filling.
• Around the city of Lanzhou, air pollution caused by dust particles is set to double and soil erosion is expected to increase by 10% due to earth-moving.

"Dozens of hills 100–150 metres in height are being flattened over hundreds of kilometres. Such infill has never been used for urban construction. There are no guidelines for creating land in the complex geological and hydrogeological conditions that are typical of mountainous zones," says the article.

As elsewhere, it is the need to save or make money that is driving the destruction. Contractors are paid to complete set projects on time. Any delays, such as a four-week delay at Lanzhou, pending an environmental assessment which never happened, cost money.

No cost modelling is being done to evaluate whether there are true economic benefits to this way of working. The authors point out that the $16 billion cost over 10 years of the Yan'an plan could take decades to recoup. There are easier ways to build cities.

The necessary specialist research expertise is frequently lacking in university departments tasked with risk evaluation; a bunker mentality dissuades cooperation and information sharing between departments; and the research briefs are narrow with economic and environmental risks not included. There is a need for international organisations and experts to offer their assistance.

"Consulting environmental scientists and economists in advance will prevent or minimize extra costs arising from delays or troubleshooting. Pausing the Yan'an excavations would cost 500,000 renminbi a day in payments to idle construction workers, for instance," conclude the authors.