ZHENGZHOU -- A Chinese water resources official on Sunday called on people to improve the awareness of water saving and protection in a bid to curb pollution of rivers from spreading and worsening.

Li Xiaoqiang, chief of publicity section with the Yellow River Conservancy Committee, made the remark over the phone while commenting on the fact that pollution had spread to one third of the Yellow River system.

With a mainstream of 5,464 km, the Yellow River, billed as the "mother river" of China, originates from Qinghai province, flows eastward through Sichuan and Gansu provinces, Ningxia Hui and Inner Mongolia autonomous regions, and Shaanxi, Shanxi and Henan provinces before emptying into the Bohai Sea from Shandong Province in east China. It has 35 main tributaries.