A case study for estimating average annual fluxes of nutrients in lake Baiyangdian, North China

Nutrient overloads are one of important environmental problems in protecting freshwater in watershed. In this study a simple strategy, based on annual nutrient budgets of water body, is presented to estimate nutrient fluxes to lake Baiyangdian. Anthropogenic nutrient fluxes (ANF) is calculated by focusing on nutrient removal fluxes by vegetations (NRFV), net loss fluxes (NLF) by physical and chemical reactions, and nutrient replenishment fluxes (NRF) by water resource allocation. The results show that in Lake Baiyangdian, 1) Cumulative anthropogenic nutrient fluxes of total phosphorus (TP) and total nitrogen (TN) during 2000 to 2009 are 647.4 ton/yr, 5878.5 ton/yr, respectively. 2) Cumulative nutrient replenishment fluxes of TP and TN during the decade are 67.3 ton/yr, 2621.2 ton/yr, respectively. 3) The efforts to restrict anthropogenic fluxes of N and P will be necessary to improve the eutrophication-related water quality of fresh waters.