Preliminary assessment of heavy metals in surface water and sediment in Nakuvadra-Rakiraki River, Fiji using indexical and chemometric approaches

River water and sediment embody environmental characteristics that give valuable management information. However, indexical chemometric appraisal of heavy metals (HMs) in river is very scarce Island countries including Fiji. In this research, forty-five fifteen samples from the Nakuvadra-Rakiraki River, Fiji were analyzed for appraising spatial distribution, pollution, source identification selected using coupling tools self-organizing map (SOM), compositional data analysis (CDA), quality indices. The mean concentration HMs increased order Cd < Co Pb Cu Zn Ni Cr Mn Fe water, respectively. outcomes enrichment factor, geo-accumulation index contamination factor varied spatially most polluted by Pb, Mn, Cu. potential ecological risk recognized Cd, as public health risks to surrounding communities. Based on SOM CDA, three sources (e.g., point, nonpoint lithological sources) two geogenic human-induced identified. patterns EWQI values revealed northern northeast zones studied area possess a high degree pollution. entropy weight indicated main pollutants degrading quality. This study gives baseline dataset combined eco-environmental measures river's pollution well contributes an inclusive global rivers.