Nutrient status of overlying water and sediment of West Lake, Hangzhou, China

A comprehensive investigation of the physicochemical properties of overlying water and sediments in Hangzhou West Lake, China was conducted. A wide range of crucial physical parameters were analyzed, revealing significant spatial and seasonal differences. Total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) concentrations in overlying water met the Class III limits (TN ≤2 mg/L, TP ≤0.2 mg/L, COD ≤20 mg/L) of the Environmental Quality Standard for Surface Waters (GB3838–2002), indicating relatively good overall water quality. However, concerns were raised regarding potential eutrophication, particularly evident during summer with explosive chlorophyll-a growth in certain lake areas like WH (266 mg/L) and XLH (239 mg/L). Lakes receiving direct diversion showed lower TN and TP versus non-diverted lakes. This research provides valuable insight into the complex nutrient dynamics and conditions of West Lake, improving understanding of lake ecosystem management and sustainable conservation strategies.