Administrative divisions of China By its political level, when a "city" is referred to, it can be a: By its actual area and population, it can be: When used in the statistical data, the word "city" may have three different meanings: It is important to specify the definition of "city" when referring to statistical data of Chinese cities, otherwise, confusion may arise. For example, Shanghai is the largest city in China by population in the urban area but is smaller than Chongqing by the population within the administration area. Before the establishment of the Qin Dynasty, China was ruled by a network of kings,
Water supply and sanitation in China undertakes research. In terms of foreign NGOs, the NGO Plan, for example, works in China. It is known for having introduced for the first time the concept of Community Led Total Sanitation in China in Puchang County in Shaanxi in 2005. Over the past 20 years, China has engaged in what is possibly the largest program to build wastewater treatment plants in history. Despite the substantial achievements of this program, many challenges remain. Achievements Until the early 1980s, there was not a single municipal wastewater treatment plant in China. In that year, the country’s first municipal wastewater treatment plant was