RELATING TRENDS OF PRINCIPAL COMPONENTS TO TRENDS OF WATER‐QUALITY CONSTITUENTS¹

Abstract

The seasonal Kendall test is used for detecting water‐quality trend or lack of trend for monthly data of 15 water‐quality constituents at 15 sampling stations in the Arkansas River, the Neosho River, and the Verdigris River basins. Trends of individual constituents and the trends of the first four principal components for the correlation matrix of water‐quality data at each station are determined, and the relationships between the trends of constituents and the trends of principal components are established. Using the principal components not only reduces the high dimensionality of the original data to a few principal components, but also presents an overall picture of water‐quality trend of these river basins.

Surface water quality evaluation using multivariate methods and a new water quality index in the Indian River Lagoon, Florida

“…At station C44S80 (G3), significant positive trends were observed for F2 scores from all‐data EFA, while F5 showed negative trend. It is worthy to note that trends detected for factors reflect an overall trend of a class of water quality variables, and would be dominant by the trends of those principal constituents that are highly correlated with the factors [ Yu and Zou , 1993].…”

“…The applications of these techniques to a variety of water quality issues including water quality assessment, water quality trends detection, water pollution sources identification, and optimization of water quality parameters and water quality monitoring stations have been reported previously [e.g., Yu and Zou , 1993; Antonietti and Sartore , 1996; Reisenhofer et al , 1998; Vega et al , 1998; Strain and Yeats , 1999; Alberto et al , 2001; Petersen et al , 2001; Santos‐Roman et al , 2003; Singh et al , 2004; Callies , 2005; Camdevyren et al , 2005; Ouyang , 2005; Kowalkowski et al , 2006].…”

Ozark-Ouachita Highlands Assessment: Aquatic Conditions

“…Water quality trends over time have been a subject of a number of investigations of streams in the Assessment area (AR DPCE 1980KS DHE 1988;Brown and others 1991;Mott 1991;Davis and Schumacher 1992;Petersen 1992;Davis and Howland 1993;Kenney and Snethen 1993;Kurklin and Jennings 1993;Petersen and others 1993;Yu and Zou 1993;Ford 1992;and Wright 1994).…”

Nonpoint sources

“…Although the observed trends are not consistent across locations, downward trends due to reduction in NPSs and increases in discharge were detected. Yu and Zou ( 1993) extended the analysis of these data using principal components or linear combinations of water quality variables weighted to represent the maximum variation or information in the data set and documented improving trends in overall water quality. K10ve et al ( 1993) estimated bacteria levels using empirical canonical correlation and regression relationships with measurements of instantaneous discharge, temperature, turbidity, pH, conductivity, and dissolved oxygen to enable immediate feedback on hygienic state for recreation of the Kerava River in southern Finland.…”