Multivariate Statistical Evaluation of Major and Trace Elements in Shatt Al-Arab Sediments, Southern Iraq

Abstract

River sediments are normally the final pathway of both natural and anthropogenic components derived or produced to the environment. As such, it is important to study these components systematically (i.e. their distribution, levels, and sources). Multivariate statistical techniques such as Principal Component Analysis (PCA) and Agglomerative Hierarchal Cluster Analysis (AHCA) as well as pollution analysis such as Enrichment Factor (EF) analysis were used to analyze the data and identify possible sources of sediment’s components in Shatt Al-Arab at Basra Governorate. The results of PCA and AHCA were compatible, defining four groups of elements; each group has a specific sourcing (a) Mg, Mo, and As show a general enrichment having mean EF values of 8.34, 12.41, and 7.01 respectively, indicating that  Shatt Al-Arab is polluted in these metals, and they are mainly of anthropogenic sources; (b) P, Cl, V, Br, Th, Cu, and Ba have mean EF values of 4.18, 3.52, 1.31, 18.85, 1.67, 2.44, and 0.54 respectively indicating that Shatt Al-Arab is unpolluted in Cl, V, Th, Cu, and Ba; minimally polluted in P, and significantly polluted with Br; (c) Al, Ni, Rb, Nb, Ga, Ti, Y, Mn, and Fe have the lowest mean EF of 1.29, 1.50, 1.07, 0.67, 1.60, 1.67, 0.91, 1.43, and 1.40 respectively; therefore, Shatt Al-Arab can be considered unpolluted in these elements; (d) Pb, Sr, Cr, Zn, and U have mean EF of 0.74, 2.38, 2.78, 2.92, and 0.80 respectively indicating that Shatt Al-Arab is unpolluted in these elements. Hence, AHCA and PCA findings are compatible with EF analysis, strongly confirming the suggested sources of elements.

Keywords: Pollution, Sediments, Multivariate Analysis, Pollution Index, Shatt Al-Arab, Basra