The study of chemical compositions by using principal component analysis in coastal water of Northern Taiwan

• Main Authors: Chiu, Chien-Chun, 邱健峻
• Other Authors: Chen, Hung-Yu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/5eqz87

碩士 === 國立臺灣海洋大學 === 海洋環境資訊系 === 102 === There has been little domestic research and investigation conducted on the chemical parameter compositions and characteristics of the seawater in northern coastal area of Taiwan. As a result, this study aims to analyze the water quality monitoring data by the mean of multivariate statistical analysis with data provided by the Environmental Protection Administration Environment Project Query system, which consist of data collected from year 2004 to 2013 through the 10 monitoring stations in the northern shore of Taiwan. Water samples from both surface and deep water collected in the 39 sampling cruises within the 10 years and a total of 15 chemical parameters including water temperature, salinity, pH, dissolved oxygen, chlorophyll a, light intensity in water, suspended solids, ammonia nitrogen, nitrate nitrogen, phosphate, silicate and heavy metals such as copper, iron, manganese, zinc, etc were analyzed. The water quality analysis results indicated that the temperature and salinity of the surface and deep water in the northern coastal area shown significant seasonal variation. The influence of weather in summer and autumn each year caused the agitation of organic compound in the sediment which led to higher measured value. In the season when the reproduction of plankton was at peak, the surface water of the shoreline and river mouth shown lower phosphate concentration level. Over the years, the concentration level of heavy metal such as copper, iron, manganese, zinc, etc conform to the quality standard of marine environment for public health with a few exceptions which had higher concentration level. The correlation analysis indicated that the variation of marine water quality was highly related to land-based sources. The effects of photosynthesis of chlorophyll a in certain area of surface water, seasonal total inflow of land water, as well as the mixing of fresh water and sea water were significant. A further investigation into the surface water characteristics of the northern coastal area through principal component analysis indicated that the distribution of nutrients in the northeastern coastal area was highly relevant to the seasonal factor. The chemical compostion parameter of the deep water was closely correlated to the temperature and nutrients, which suggested that the seasonal factor has significant impact on the distribution of nutrients, which displayed seasonal variation. Furthermore, the factors that have significant impact on the rest of the components were land-based sources, biotic factor, the mixture of fresh and sea water, and nitrogen sources.