Water Quality Analyses in Sun-Moon Lake Reservoir using Statistical Methods and Continuously Automatic Monitoring System

• Main Author: 林炤映
• Other Authors: Chi-Wen Lin
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/63773751614149955524

碩士 === 大葉大學 === 環境工程學系碩士班 === 92 === The study analyzes hourly monitoring data samples of water quality in Sun-Moon Lake reservoir using statistical methods to investigate the characteristics of water quality for a pumped storage hydro power plant reservoir. The researchers have monitored 11 parameters during one year including: temperature, salinity, conductivity, total dissolved solid, resistivity, dissolved oxygen, pH, ammonium, nitrate, transmissivity, and chlorophyll-a. Water samples were collected by two continuously automatic monitoring systems installed in Lalu Island and an outlet zone for drinking water supply in the reservoir. Initially a nonparametric procedure was used to examine the difference of water quality between day and night’s operation for hydro power generation. For detecting the possible intervention in the data a correlation analysis was conducted. Then, the 11 parameters were treated using factor analysis and cluster analysis to group the selected parameters according to common features. Finally, an autoregressive moving average (ARMA) model was applied to establish the relation of common factors and time, and the proposed model can be provided for future use in foresting the trends of water quality for temporal change. Of the 11 parameters, only the daily and nightly means of dissolved oxygen (DO) and pH were found significant difference. Factor analysis for the water quality data renders four factors for water quality investigated in Lalu Island and an outlet zone for drinking water supply in the reservoir, respectively. Results from Lalu Island investigation indicate four factors including “turbidity factor”, “nutrient factor”, “eutrophication factor”, and “pH factor”, accounting for 89.05% of total variance. Results from investigation on an outlet zone for drinking water supply in the reservoir indicate four factors including “turbidity factor”, “nutrient factor”, “eutrophication factor”, and “transmissivity factor”, accounting for 86.63% of total variance. Water quality data in twelve months were grouped into three categories by cluster analysis. Results indicate they are no seasonal and cyclic patterns for both in Lalu Island and an outlet zone for drinking water supply in the reservoir. This research also proposes eight best ARMA models. The models were recommended for forecasting of water quality parameters for Sun-Moon Lake reservoir.