Source Apportionment of Water Pollution in the Jinjiang River (China) Using Factor Analysis With Nonnegative Constraints and Support Vector Machines

摘要

Source apportionment studies of water pollution can greatly improve the knowledge of the human impact on the aquatic environment. Factor analysis (FA) has been widely used to identify sources of water pollution because of its relative ease of implementation. Generally, the method of identifying the sources was by qualitatively comparing source emission characteristics with factor loadings derived from FA. However, this traditional method was somewhat coarse to express the nonlinear relationship between source emission characteristics and factor loadings. In this study, by treating source identification using source emission characteristics and factor loadings as a pattern recognition problem, a source apportionment method was proposed by combining the factor analysis with nonnegative constraints (FA-NNC) with the support vector machine (SVM). Data sets on water quality of the Jinjiang River (China), which were sampled between May 2009 and September 2010 at 13 sites, have been collected to evaluate this proposed method. The apportionment results showed that the identified sources using the combined models were similar to the comprehensive analysis results obtained from qualitatively comparing source emission characteristics with factor loadings. Industrial activities, including papermaking and textiles, metal handicrafts manufacture, chemical and metal producing, metal refining and iron ore mining were identified as the main pollution sources with contribution ratio of 79.58%, followed by agricultural non-point sources (20.42%). These results provide policy and decision makers with a useful help for supporting the management of water pollution in the Jinjiang River. Meanwhile, this study will provide a useful direction for developing source apportionment approach to support the management of water pollution.