Unmanned Technology Narrows Data Gap of the World’s Most Sediment-laden River

The world’s Most Sediment-Laden River

With a total length of 5,464 km, the Yellow River is the second-longest river in China. As running through the Loess Plateau during the middle journey and carrying much sand and dust, it is then becoming the most sediment-laden river in the world. Yellow river runs through 9 cities of China and is affecting the daily lives of tens of thousands of people live alongside the river.

Monitoring the changes of underwater terrain and studying the pattern of river evolution can provide important data support for river management and flood control, to better protect the ecology of the watershed.

However, due to technical limitations and harsh environment conditions, the Yellow River watershed has not been meticulously mapped. The waters are complex with rapid currents and many shallows. With traditional measurement methods, it’s difficult to install survey equipment and rent a suitable workboat. Operating on water also poses high risks to personals.

Unmanned Technology Solution

Not long ago, the Second Topographic Survey Team of the Ministry of Natural Resources used intelligent equipment such as unmanned aerial vehicles and unmanned surface vessels to carry out integrated multi-element topographic surveys in the Qiankun Bay section of the Yellow River.

The underwater topographic survey was carried out using OceanAlpha’s ME120 autonomous surface vessel platform equipping a multi-beam sounding system.

The ME120 USV adopts a modular design that its three pieces can be quickly disassembled and assembled. It can work automatically and sail into super shallow water areas as 0.45 meters. All these advantages enable it to be well adapted to operations on such complex waters.

The transducer and sound velocity meter of the multi-beam system was installed in the lifting mechanism of the USV. Through the USV shore-based control base station, the lifting mechanism can be remotely controlled to raise or lower the wet end equipment. There is no need for personnel to stay on board for retracting operations. The lifting mechanism reduces the risk of equipment damage and better guarantees the safety of personnel. 

Personnel install and debug equipment at the dock. 

According to the real-time measured water depth and multi-beam span, the surveyor set up parallel survey lines and inspection lines with the base station software from the dock. The USV navigated according to the survey line instructions, and the collected data was sent back to the shore-based control terminal in real-time.

ME120 USV navigates autonomously to perform mapping task

Satisfying Survey Result

The collected data delivers high quality and clear reflects of the topography of the river. The ME120 USV was also equipped with a high-precision inertial navigation system, which provides strong support for the seamless splicing of multi-beam data and UAV data. After analysis and processing, the team obtained high-quality integrated above water and underwater data of the Qiankun section.

The result of above water and underwater integrated mapping