More drones to detect sewage outlets along Yangtze River

CHANGSHA - The central Chinese province of Hunan will fly 20 drones to spot sewage disposal along its section of the Yangtze, China's longest river, local authorities said Friday.

The province's ecology and environment department said the unmanned aerial vehicles will be equipped with high-resolution infrared cameras capable of revealing small and hidden sewage outlets.

They will fly over 163 km along the Hunan section of the Yangtze and 840 km along the Xiangjiang River, a major Yangtze tributary, according to the department.

Officials said they decided to use drones as some target areas are densely forested and difficult to access via land travel. The images collected by drones will be analyzed to facilitate future investigations.

The Hunan action followed a similar operation launched by the eastern Jiangxi Province earlier this week to fly drones to detect sewage outlets along its section of the Yangtze.

China earlier this year unveiled an action plan to protect and restore the Yangtze with goals including eliminating more than 90 percent of "black and odorous" water bodies in cities at or above the prefecture level in the Yangtze River economic belt by the end of 2020.