Current status and characteristics of urban landscape lakes in China

Urban landscape lakes (ULLs) are important environmental elements in most cities. In order to understand the current situation of ULLs in China and formulate proper strategies to improve their landscape quality to meet public desire for water-front enjoyment, a study was conducted of 189 ULLs widely distributed in 26 provinces of China, based on existing data and field surveys. These ULLs were firstly categorized according to their topographic features, climatic zones, and water replenishment sources. Lake water quality was evaluated considering both single factors and a comprehensive pollution index (CPI). Results show that if the Chinese Surface Water Quality Standard was used as the sole criteria, about 60% of the ULLs investigated could not meet the lowest requirement. Excessive total nitrogen (TN) concentration was the most limiting factor especially when reclaimed water was the replenishment source. The differences in topographic and climatic conditions to a certain extent affected the availability of replenishment water sources but no significant correlation was identified with the single water quality factors or CPI. However, when public satisfaction was introduced in the evaluation of the ULLs' landscape effect, it was found that the water transparency in terms of Secchi Depth (SD) correlated well with people's appreciation of water landscape.