Hengshui (China) is 2.8 times larger than Bauchi.
Area: 3,188 km2 calculated
Bauchi is a city in northeast Nigeria, the capital of Bauchi State, of the Bauchi Local Government Area within that State, and of the traditional Bauchi Emirate. It is located on the northern edge of the Jos Plateau, at an elevation of 616 m. The city has a population of 316,173. Wikipedia
Area: 8,846 km2 calculated
Hengshui is a prefecture-level city in southern Hebei province, People's Republic of China, bordering Shandong to the southeast. It has an urban population of 460,240 in the built-up area and a population of 4,340,373 at the 2010 census in its administrative area. It is on the Jingjiu Railway. Wikipedia