Assessment of surface water quality using PCA and FA in Jinghe River of Shaanxi Province, China

Assessment the changes of surface water quality in different times throughout one year is an important aspect for evaluating temporal variation of river pollution due to natural or anthropogenic input of point and non-point sources to water environment that is gradually deteriorating. In this paper, principal component analysis & factor analysis (PCA & FA) is conducted according to the average value of 16 monitoring data taken from Shaanxi Reach of the Jinghe River in three years and dividing it into dry season, normal-water season and wet season. And the most important water quality parameters in different times is selected according to the standard that the correlation coefficient value of water quality variable of rotated factor loaded matrix is larger than 85%. Analysis shows that the most important parameters are mainly salinity indexes of natural input in dry season, the main parameters in wet season are indexes of non-point source pollution by anthropogenic input (including nitrogen nutritional index and salinity index) and the index of upstream organic pollution (volatile phenol) which is carried by large amount of runoff. No obvious regularity in other water period. And sulfate is always the most important water quality parameter in Jinghe River, Shaanxi Province in different water period.