Differentiating the spatiotemporal distribution of natural and anthropogenic processes on river water-quality variation using a self-organizing map with factor analysis
Journal
Archives of Environmental Contamination and Toxicology
Journal Volume
69
Journal Issue
2
Pages
254-263
Date Issued
2015
Author(s)
Abstract
To elucidate the historical improvement and advanced measure of river water quality in the Taipei metropolitan area, this study applied the self-organizing map (SOM) technique with factor analysis (FA) to differentiate the spatiotemporal distribution of natural and anthropogenic processes on river water-quality variation spanning two decades. The SOM clustered river water quality into five groups: very low pollution, low pollution, moderate pollution, high pollution, and very high pollution. FA was then used to extract four latent factors that dominated water quality from 1991 to 2011 including three anthropogenic process factors (organic, industrial, and copper pollution) and one natural process factor [suspended solids (SS) pollution]. The SOM revealed that the water quality improved substantially over time. However, the downstream river water quality was still classified as high pollution because of an increase in anthropogenic activity. FA showed the spatiotemporal pattern of each factor score decreasing over time, but the organic pollution factor downstream of the Tamsui River, as well as the SS factor scores in the upstream major tributary (the Dahan Stream), remained within the high pollution level. Therefore, we suggest that public sewage-treatment plants should be upgraded from their current secondary biological processing to advanced treatment processing. The conservation of water and soil must also be reinforced to decrease the SS loading of the Dahan Stream from natural erosion processes in the future. © Springer Science+Business Media New York 2015.
Other Subjects
copper; industrial chemical; organic compound; river water; water pollutant; anthropogenic effect; factor analysis; mapping method; metropolitan area; pollutant source; pollution monitoring; river pollution; river water; sewage treatment; soil conservation; spatiotemporal analysis; water quality; water storage; Article; artificial neural network; factorial analysis; organic pollution; pollution monitoring; priority journal; river basin; self organizing map; suspended particulate matter; Taiwan; water pollutant; water pollution; water quality; analysis; chemistry; environmental monitoring; factorial analysis; procedures; river; spatiotemporal analysis; standards; statistics and numerical data; water quality; Dahan River; Taipei; Taiwan; Environmental Monitoring; Factor Analysis, Statistical; Rivers; Spatio-Temporal Analysis; Water Pollutants, Chemical; Water Pollution, Chemical; Water Quality
Type
journal article