Spatial water quality analysis of the watercourses in Northwestern New Territories (Hong Kong)

Abstract

River water is an important source for drinking water supply in Northwestern New Territories of Hong Kong. Thus, there is no denying the fact that monitor the quality of river water is a must for the locals. In this study, a mixed multivariate analysis method was used to lower monitoring costs by optimizing the layout of water quality monitoring stations. To this purpose, the data from a period of five years and over 36,000 observations was evaluated in this article. The cluster analysis approach was also used to categorize monitoring stations into three groups. What's more, three latent factors that predominantly influence the river water quality were assessed using factor analysis: anthropogenic pollution, seawater intrusion and geological processes, and the nitrification process. A spatial pattern using the three latent factor scores was plotted and six redundant monitoring stations were identified by this pattern. Finally, discriminant analysis was used to extract seven significant parameters. The results showed that the surface water-monitoring program of the watercourses in the Northwestern New Territories (Hong Kong) could be adjusted by reducing the monitoring stations to 18 and the measured chemical parameters to seven to ensure the detection of water quality and reduce the cost. HIGHLIGHTS Studying the spatial variation of water resource by a mixed multivariate statistical method.; Performing cluster analysis for three latent factors that affect river water quality.; Establish evaluation system to identified redundant monitoring stations.; Extract seven significant parameters for measuring the contamination conditions.; Give a more reasonable monitoring station layout to ensure the detection of water quality and reduce the cost.;

Keywords

• cluster analysis
• discriminant analysis
• factor analysis
• hong kong
• spatial variations
• water quality