Water pollution characteristics of Dianchi Lake and the course of protection and pollution management

Since the 1980s, Dianchi Lake Basin has been experiencing rapid social and economic development and accelerating urbanization. Hence, the water quality of Dianchi Lake is constantly deteriorating as a result of the great population burden and pollution loading. The problem of eutrophication and the large gap between supply and demand for water resources requires urgent resolution. Therefore, the changes in water quality in Dianchi Lake and their social impact, the economic development of the basin, and population aggregation on water quality are discussed in this paper. The history of the protection and pollution control of Dianchi Lake can be divided into three stages: (1) the initiation and exploration stage [from the Seventh Five-Year Plan (1986–1990) to the Ninth Five-Year Plan (1996–2000)], which focused on the construction of laws, regulations, policies, plans, and systems of environmental protection; (2) the difficulty tackling stage [from the Tenth Five-Year Plan (2001–2005) to the Eleventh Five-Year Plan (2006–2010)], during which the efficiency of pollution control increased considerably and the trend of water quality deterioration was reversed; and (3) the preliminary achievement stage [since the Twelfth Five-Year Plan (2011–2015)], in which the primary task was to actively explore new ways of combining pollution control, protection, and development of Dianchi Lake. The focus of future plans for pollution management in Dianchi Lake is also explored, and a reference is provided for protection and pollution management in the lake.