The settlement and transfer rule of phosphorus in stormwater runoff from phosphorus-rich area in Dianchi Watershed
滇池流域富磷地区暴雨径流中磷素的沉降及输移规律

The phosphorate resources distribution and mining in Dianchi Watershed is one of the important reasons for eutrophiction of Dianchi Lake.The phosphorus concentration and particle size distribution in surface runoff produced from 3 land use types were determined to analysis the phosphorus transfer process during rainstorm in phosphorus-rich area of Dianchi Watershed.The results showed that:①The phosphorus concentrations of runoff were significantly different among 3 land using types.The sequence of TP concentration in runoff among 3 land use types was the Phosphate mining area>the Woods>the Tableland.②After 8 hours sedimentation processes,the TP concentration of runoff reduced significantly.③Within two storm incidents,63.3% of phosphorus were lost within particles size smaller than 0.02 mm on average.Moreover,43.8% of phosphorus were lost within particles size <0.008 mm on average.④Only 1.5% of TP lost from the original areas was flushed into the stream through runoff.It means that TP in storm runoff mainly lost in particles size <0.02 mm.It can be effectively removed by settling process,and ditch system is a very import way for non-point TP pollutant control.