Review of studies on nitrogen and phosphorus transport in the continuum of watersheds,estuaries and offshore areas

The paper reviews the main sources of nitrogen and phosphorus nutrients,as well as their transports in watersheds,estuaries and offshore areas.The leading methods of simulating nutrient transports are introduced,and the comprehensive studies on nitrogen and phosphorus transport in an integrated system of watersheds,estuaries and offshore areas are also summarized.Finally,the main problems and future prospects on the issues of eutrophication are discussed,the coupling of watersheds,estuaries and offshore areas should be focused,and the advantages of distributed models should be taken full in the study of nutrient transports in future.