Beidou saving lives in battle against flooding

Officials in Hunan province using intelligent app to predict, tackle threat of rising water

A torrent of mud throws rocks and tree trunks down the mountainside, engulfing houses before the eyes of residents.

It was the largest landslide to hit Shimen county in Changde city, Central China's Hunan province, in 70 years. Fortunately, no one was killed or injured in the July 6 incident thanks to an early warning by a disaster alert program backed by the Beidou Navigation Satellite System, China Intellectual Property News reported.

Local authorities have been using technology, such as Beidou, to predict flooding along the Yangtze River.

The Beidou system monitors deformations and displacements in mountains, reservoirs and rivers around the clock and issues warnings on landslides, subsidence, crevices and water-level surges, according to CIPN.

Beidou is China's largest space-based system and one of four global navigation networks.

As of Dec 31, 2019, China's applications for satellite navigation-related patents had exceeded 70,000, the largest in the world, the Beijing-based newspaper reported.

Wang Dunlei, director of the Changde flood and drought prevention and mitigation center, told CIPN that Shimen county received the alert on June 24, more than 10 days before the landslide struck.

"Only by combining people, supplies and technology can we better respond to natural disasters and protect people's lives and property," Wang said.

Another technology that can help prevent disaster is a three-dimensional electrical resistivity imaging system developed by East China University of Technology.

Electric fields change as an electric current hits different geological masses in the dam, CIPN quoted Deng Juzhi, dean of the School of Geophysics and Measurement-Control Technology at the university, as saying.

By collecting the data, the system is able to "see through" the dam and determine whether there are hidden hazards such as voids, cracks, seepages and unstable soil.

"The whole process is like performing a CT scan on the dam, which can help ensure the dam is 'healthy' before floods arrive," Deng said.

Applications for a number of patents related to this new technology have been filed, Deng said. He added that the technology is being used to detect safety hazards in coal mines, seepages at landfills and subterranean cavities. It is also being used in archaeological excavation and urban underground space management.

An official with the Hunan Provincial Department of Water Resources told CIPN that some counties use drones to patrol dams and collect flood-related data, based on which a three-dimensional model of the dam is made.

Using high-tech equipment to patrol the dams is much safer than sending people, the official added.

On top of the high-tech equipment and systems, mobile apps have been created to update the public on flooding situations.

Hunan province has launched a mobile app to provide historical and real-time data on the weather, rainfall, water levels and the amount of water entering and leaving reservoirs, CIPN reported.

Jiangxi province in East China has introduced an app that can be used to record the location of sinkholes, landslides and riverbank collapses. Also, people can access dam drawings and information on rainfall and floods in surrounding areas.

Rescue equipment such as amphibious vehicles and rescue robots are also being deployed to the front lines of the battle against floods.

The rescue robot looks like a small boat, an official with the emergency management bureau of Wuhan in Central China's Hubei province told CIPN.

The remote-controlled robot travels at more than 6 meters per second and can return to its starting point at the push of a button. It is capable of rescuing up to four people at a time, the official added.