The origin of lakes in Beijing City

Abstract：Beijing, as the capital of China, is well-known for plenty of lakes in its historical period. The distribution and origin of these lakes are highly controlled by the geological structure of Yongding River alluvial fan. By analyzing the type of sediment distribution, the characteristics of structure and the locations of present lakes, this paper deals with the distribution regularity of these lakes. There exists a clear geological boundary, as shown by the differences of geological structures. The western part of Beijing plain is a single gravel layer rich in underground water, while the eastern part is mainly of the clay-interbedded-with-silt water retaining structure poor in underground water. Lakes are divided into different genetic types by the geological boundary. The most western lakes, such as Kunming Lake, Fuhai Lake, Zizhuyuan Lake, Yuyuantan Lake, Lianhuachi etc., are dominated by the spring and depression genesis, whereas the lakes in the eastern part are dominated by residual water bodies of the old channel of the Yongding River. Studies show that geological structures are the main control factors for the distribution of lakes in Beijing City with certain regularity, and that urban planning and construction should follow the natural law. The results obtained by the authors have important significance for urban development, disaster prevention and reduction as well as rational utilization of water resources.