Multivariate statistical analysis for sedimentary characteristics in an estuarine environment of the east flood canal river, Semarang

Abstract

The East Flood Canal River stretches across the eastern part of Semarang, an area that is densely populated with residential and industrial areas. There are many human and industrial activities around this watershed, including the textile industry, food factories, and fish auction sites. Therefore, this river becomes an interesting research object to examine the influence of industrial activities around the river on the characteristics of the sediment. This research was conducted by examining sediment core samples from the estuary of the East Flood Canal. The research aims to reveal the relationship between the characteristics and distribution of sediments and geochemical trace elements. A total of 31 samples of sediment core slices with an interval of 1 cm were analyzed. The granulometric analysis was conducted by Mastersizer 2000, to determine the grain size parameters that were used as the basis for the clustering. Geochemical analysis was conducted by the XRF (X-Ray Fluorescence) to determine the trace elements concentration. The study is interpreted using compositional data analysis associated with a grain size trend analysis (GSTA) and cluster analysis (CA). The GSTA value showed generally dominated by medium to very fine silt. The cluster showed that four lithofacies zones have different sedimentary characteristics. The distribution of the characteristics of the large grain size of the seafloor sediment in the East Flood Canal indicates that as the deposition is farther from the river mouth, the poorer it’s sorting. It was recorded that, at a depth of 19 to 27 cm from the surface there was an increase in fine to very fine sand accompanied by an increase in the Fe and Mn which indicated that there was a supply of sediment that occurred from land caused by human activities and flood events.