Variation of TP flux in Jialing River and spatial source apportionment
The interannual variation and seasonality of runoff,and the concentration and flux of suspended sediment(SS)and phosphorus(P)(including total phosphorus(TP),dissolved phosphorus(DP),and particulate phosphorus(PP))at Beibei section in the Jialing River were studied during 2002 through 2019.Based on the principle of river base flow segmentation,P loads were apportioned in terms of point and non-point sources.The results show that∶(1)From 2002 to 2019,SS concentration and flux fluctuated greatly,and the maximum annual flux was greater over 20 times than the minimum.(2)The average concentration of TP in the whole period was 0.098mg/L with an annual average concentration ranging 0.058～0.139mg/L.During 2002～2013,concentrations of TP and PP were higher in the wet season than those in the even and dry seasons.During 2014～2019,some years saw the same pattern as during 2002～2013,while others saw the opposite direction.(3)DP concentrations increased first(2002～2016)and then decreased(2016～2019)at large.(4)The TP and PP fluxes showed significant interannual fluctuation in 18 years,and the maximum TP flux(22800t/a,2005)was 5.7 times higher than the minimum(3990t/a,2006).The water discharge,sediment discharge,and TP and PP flux exhibited a certain degree of synchronous effect in interannual trend,especially in the wet season.(5)TP,PP and DP fluxes in the wet season were much greater than those in the even and dry seasons,and they accounted for respectively 73.5%,77.5%,and 64.9%of those in the whole year.(6)Loads from point sources displayed stronger interannual fluctuation than those from non-point sources,and the interannual trend of the total load depended on that from non-point sources.TP load from non-point sources contributed the absolute majority of the total load in every year except for 2006,and its percentage was averagely 82.5%for the whole year and 90.8%for the wet season.Also,The annual load from non-point sources mainly came from the wet season(averagely 81.2%).
万方数据
维普
