On this day, 52 years ago, November 16, 1973 (October 22, 1973 in the lunar calendar), the Haihe River was eradicated. In November 1973, the people of Hebei, Shandong, Beijing and Tianjin responded to Chairman Mao Zedong's call to "cure the Haihe River" and fought hard for ten years and achieved a huge victory. Under the unified national plan, comprehensive control has been carried out to floods, waterlogging, drought, alkali and other disasters. More than 4300 kilometers of flood control embankments have been built, more than 270 tributary rivers have been excavated and dredged, and more than 60,000 new culverts, bridges, and gates have been built., making the Haihe River's flood discharge capacity into the sea more than 10 times higher than before liberation. At the same time, a number of reservoirs have been expanded and built, and a number of mechanical wells have been dug, allowing each person to irrigate one acre of land. The total grain output has doubled compared with 1963.