Sediment Sources And Particulate Phosphorus Sources Apportionment In A Small Catchment Of The Upper Jiuxiang River Using Composite Fingerprinting

Sediment will not only increase water turbidity, change the channel morphology, but also an important carrier of phosphorus and other pollutants, studies show that particulate phosphorus output total annual total phosphorus load of up to75%-95%. Establishing the relative contributions from the sediment source has great significance to pertinently control the soil erosion, study the source and process of water environment pollution and implement an effective control of pollution. The upstream of Jiuxiang Rive, in Nanjing, Jiangsu Province, was selected as the study area in this paper. Using the composite fingerprints and multivariate mixing models to estimate the relative contribution of the potential sediment sources, and the aim is to investigate whether it is feasible to use composite fingerprinting technique to study sediment source in small catchments with relative uniform geological or geochemical properties. Based on the sediment source calculation results, the paper preliminarily analyses total particulate phosphorus sources. The main conclusions take follow:1Assessing the ability of the tracer properties to discriminate the sources typesIn this study we analyzed twenty-three kinds of soil properties. All analyzed soil properties were tested for their ability to distinguish individual source types, using non-parametric Kruskal-Wallis H test. Totally,11properties which contain Na2O, A12O3, SiO2, P, K2O, Zn, Cd, As, Sn, N and C yielded P-values lower than0.05. It shows that these properties have significant difference between the three sediment source areas and they can use as fingerprinting factors.2Identifying the best composite fingerprint for discriminating source materialsStepwise multivariate discrimiant function analysis was employed to identify an optimum composite fingerprint from the properties selected. When sediment samples showed no abnormal values(#1-#14), Na2O、Al2O3、P、Sn、N make the optimum composite fingerprint and87.5%of the total source material samples was classified correctly. When there is an abnormal value index(#15:Na20;#16: Al2O3, SiO2, As, C;#17:Zn, N), first remove them, and then use multiple discriminant analysis. The results showed that the best composite fingerprint in#15and#17are Na2O, A12O3, P, Sn, N and Na2O, A12O3, P, Cd, and the correct classification rate of83.3%and85.4%respectively.#16sediment samples discrimination rate of less than80%, which does not meet the acceptable range, it was excluded.3Establishing the relative contributions from the individual sediment source and documenting the availability of using composite fingerprinting technique to study sediment source in small catchments with relative uniform geological or geochemical properties.The results showed that the relative contributions from agricultural land, mine land and wood land ranged between25.3%-65.2%,34.8%-74.7%and less than0.1%respectively. A discriminatory efficiency of87.5%was provided for discriminating the different sources by the optimum composite fingerprint and a mean model GOF (goodness of fit) was up to0.93. It concluded that sediment fingerprinting could also provide reliable results in small catchments with relative uniform geological or geochemical properties.4Preliminarily analyses total particulate phosphorus sourcesThis study has established the corresponding relation between output and source of phosphorus particles on the base of calculation of sediment sources, and then it has analyzed the output of particulate phosphorus. The results showed that the relative particulate phosphorus contributions from agricultural land, wood land and mine land ranged between32.6%-72.79%,0.02%-1.89%and27.19%-67.37%.