On Sanmenxia Dam in central China's Henan Province, a massive hydrological project built in the 1950s and the first of its kind along the Yellow River, there are paintings of eight characters that say, "When the Yellow River is at peace, China is at peace."

The river's large sediment load has historically made it prone to flooding, earning it the name "China's Sorrow" and legend has it that Yu the Great, one of China's first emperors, established his legitimacy to rule by bringing the Yellow River floods under control.

That legend, allegedly took place in Longmen, near the exit of a canyon dividing today's Shanxi and Shaanxi provinces, and while you probably will not find signs of Yu the Great, you will see there stands a cliffside hydrometric station which has a critical role when it comes to preventing floods downstream.

For outsiders, work and life at the station may be intriguing, since the only way to access their workplace is through two ropeways and cages. But after a few days spent observing how technicians get their job done, we came to understand that it is a line of work that requires a high-level of professional ethics. Besides, in modern-day China, the Yellow River still poses unique challenges to flood forecasting.