Exploring between site differences in water quality trends: a functional data analysis approach

✍ Scribed by Brent Henderson

• Book ID: 102185914
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 157 KB
• Volume: 17
• Category: Article
• ISSN: 1180-4009
• DOI: 10.1002/env.750

✦ Synopsis

Trends in ecologically meaningful water quality variates are important for establishing changes in water quality. Linear assessments of the trend at different monitoring sites are relatively easy to compare but may be misleading as they can poorly represent the nature of the trend. Non-linear trends, on the other hand, more faithfully capture the trend but have been much more difficult to compare between sites. In this article we investigate the ability of functional data analysis to explore between site differences in non-linear water quality trends. Functional data analysis is briefly reviewed, concentrating in particular on the techniques of functional principal component analysis, functional linear modelling and functional cluster analysis. These techniques are then applied to some nutrient and sediment trend data obtained from a number of monitoring sites in three dams in South East Queensland, Australia. Functional data analysis is found to be a valuable exploratory tool for providing insight into the between-site, depth and dam differences.