Precipitation in the Qilian Mountains has increased by 14 percent over the past decade, and the annual flow of nearby rivers has also increased by 10.8 percent, according to the Gansu provincial government.

Qingtu Lake on the lower reaches of the Shiyang River, which originates in the Qilian Mountains and provides Wuwei with most of its water needs, has expanded to cover 26.7 square kilometers.

The increase is mainly due to Wuwei's weather modification technicians.

The practice of weather modification in the city started in 1995. For the first 15 years, operations were not conducted from a fixed place.

Instead, rainmaking equipment was sent to wherever atmospheric conditions were best suited to cloud-seeding.

Yan Hu still remembers the celebrations that would accompany the arrival of the cannons used to shoot silver iodide into the clouds to create artificial precipitation.

"People beat gongs and drums, hoping for rain with the help of the cannons," the 66-year-old said.