Multivariate statistical assessment of the pollution sources along the stream of Kamchia River, Bulgaria.

Sixteen sampling sites along the stream of Kamchia River were considered as environmental objects in the multivariate statistical study aimed to identify and apportion patterns of sampling sites, latent factors responsible for the data structure and their relation to the emitter industrial and anthropogenic sources in the vicinity of the sampling sites. As variables 11 surface water parameters monitored for a long time period (up to 11 years) were used. Four main site patterns were revealed by cluster analysis (urban, rural, near-to dam and estuary) and for each site latent factors were identified and apportioned (among them "metallurgical", "food production", "winery", domestic wastes", "natural"). The relative contribution of each identified pollution source to the formation of the total concentration of each chemical species or physicochemical parameter was determined and compared to the real emitters in the region of interest.