Application of multivariate statistical techniques to evaluate organic pollution on a river in Argentina

Abstract

The aim of this paper was the application of multivariate statistical techniques to evaluate spatial and temporal variations in the water quality of Potrero de los Funes River using physical, chemical and bacteriological parameters and select the most significant parameters of organic pollution in the river in order to implement in the future water quality monitoring. The river was monitored regularly at three sites: RP1, RP2 and RP3, over the period 2008–2009, for 16 parameters. The complex data matrix was treated with three multivariate statistical techniques: cluster analysis (CA), principal component analysis (PCA) and discriminant analysis (DA). CA generated three groups of sites, cluster 1 (RP1), cluster 2 (RP2) and cluster 3 (RP3) according to relatively low, very high and moderate pollution regions, respectively. PCA identified two components, which were responsible for the data structure explaining 73% of the total variance of the data matrix. Temporal DA (Wet season and Dry season) showed that turbidity, NO3- and COD were the discriminant variables. Spatial DA shows that there were significant differences between the three categorical classes, 1 (RP1, low pollution region), 2 (RP2, strongly polluted zone) and 3 (RP3, moderate polluted site) .The discriminating functions contained only eight parameters (EC, NO3-, turbidity, DO, BOD, COD, total coliform and fecal coliform) to discriminate between sites. The application of these techniques has achieved meaningful classification of physical, chemical and bacteriological variables and of river water samples, based on seasonal and spatial criteria. This study is essential for the future design of fast and effective monitoring programs of river water quality. That would include only parameters that are indicative of organic pollution

Assessment of the environmental quality of two urbanized lotic systems using multiple indicators

“…The contribution of variations in dissolved oxygen and temperature was minor but significant. Previous studies have shown a deterioration of surface waters downstream from PR2, coincides spatially with the most urbanized part of the town and temporally with the increase of tourist activities during the summer season (Oliva González et al, ). Almeida et al () applied a General Quality Index calculated from 11 parameters, including bacteriological measurements and likewise reported a decline of water quality in zones of the river located in the urbanized area of Potrero de los Funes town.…”

“…Site PR1 was considered as the reference site. Previous studies assessed PR1 as the area of environmental base line of water quality on the basis of physical–chemical and bacteriological analysis (Oliva González et al, ). PR1 also represents the initial stretch of PR, where its two tributaries streams converge.…”

“…Previous studies (Almeida, Quintar, Gonzalez, & Mallea, ; Oliva González, Almeida, Quintar, Mallea, & Gonzalez, ) assessed physical–chemical and bacteriological water quality of upper, middle, and downstream sections of the Potrero River (PR). Upper sites had low interference from anthropogenic activities and represented the “environmental base line” of the watercourse; middle sites were within fully urbanized areas near wastewater drainages from residential buildings and hotels, and downstream sites were located at the end of the urban area, before draining into the Potrero de los Funes reservoir.…”

“…Water quality of PR was deteriorated downstream from urbanized areas with an increase of organic load and nutrients (phosphorous and nitrogen). This loss of quality had a temporal pattern linked to the increase of tourist activities during the summer (Almeida et al, ; Oliva González, Almeida, Calderón, Mallea, & González, ; Oliva González et al, ).…”

Concentración de clorofila-a y límite de zona fótica en el embalse Río Tercero (Argentina) utilizando imágenes del satélite CBERS-2B

“…La literatura muestra que a la hora de generar un programa para el análisis de la calidad del agua en un reservorio acuático, los parámetros bio-físicos comúnmente seleccionados son la concentración de clorofila-a, los sedimentos en suspensión y la transparencia del agua (Zhu et al, 2005;Gonzalez et al, 2011). La transparencia del agua, es expresada como el límite de la zona fótica (z-fot).…”