Spatial-temporal Features of Atmospheric Deposition of Nitrogen and Phosphorus to the Lake Taihu

To probe atmospheric deposition characteristics of nitrogen and phosphorus nutrients in the Lake Taihu and their contributions to the lake,these were analyzed that various forms and fluxes of nitrogen and phosphorus of samples collected from different sites of Lake Taihu at different seasons in 2011.The results showed that phosphorus was mainly from dry deposition,whereas atmospheric rainfall was a major source of nitrogen into the Lake Taihu.The total inorganic nitrogen(TIN) accounted for 77.1% of total nitrogen(TN) in dry deposition,while dissolved total phosphorus(DTP) accounted for 77.9% of total phosphorus(TP).NH+4-N was a major source of TIN in dry deposition.The input of TN and TP from atmospheric deposition in the West Lake Taihu was the highest.The estimated annual atmospheric deposition fluxes of TN and TP in Lake Taihu during 2011 were 20 978 tons and 1 268 tons,respectively.Therefore,the atmospheric deposition of nitrogen and phosphorus was one of important nutrients sources to Lake Taihu.