Influence of urbanisation on water quality in the basin of the upper Uruguay River in western Santa Catarina, Brazil

Abstract

AIM: The main objective of the study was to evaluate the limnological characteristics of rivers flowing through urban and rural areas in the upper Uruguay River basin in western Santa Catarina (SC), Brazil. METHODS: Sampling sites in the tributaries were selected along the longitudinal gradient and the different use of the soil in adjacent areas. Samples were collected bimonthly from March 2005 to August 2006. The following were analysed: depth, pH, electrical conductivity, dissolved oxygen concentration (DO), water temperature, chemical oxygen demand (COD), total alkalinity, ammonia, nitrite, nitrate and phosphorus were analysed. RESULTS: In most of the rivers analysed, we found a continuum from the spring to the river mouth that was characterised by a gradual increase in electrical conductivity, COD, phosphorus, alkalinity, nitrite and nitrate. However, an alteration from this pattern was found in rivers passing through urban areas. This deviation was due to high organic matter input poured into the rivers from these areas. CONCLUSIONS: Degraded riparian forest was observed along most of the bodies of water, which facilitates the entry of pollutants. Although the studied area suffers from intense farming activity (agriculture and livestock) and has the highest concentration of swine livestock in the country, the rivers that were most altered from their natural state were those that were influenced by sewage and industrial effluents from urban development.

Alpha and beta diversity of phytoplankton in two subtropical eutrophic streams in southern Brazil

“…This fact indicates that, regardless of a stretch being protected or not by the forest, exposure to human interference occurs at some level. The environment´s trophic level may have contributed to the high richness of algae along the rivers since phosphorus is usually a limiting resource for primary productivity (Ternus et al 2011). The de-characterization of the longitudinal profile may be attributed to land use and occupation in the areas close to the sources of the two rivers, where crop cultivation and intensive animal breeding predominate and the streams are not protected by riparian vegetation.…”

“…The current investigation shows the importance of surface drainage in contributing electrolytes, which were much higher in the stretches close to the sources of the rivers. Research by Ternus et al (2011) showed that nitrogen and phosphorus concentrations in lotic environments can be greatly affected by the use and occupation of the soil by agricultural activities.…”

Integrated Environmental Assessment of streams in the Sinos River basin in the state of Rio Grande do Sul, Brazil

“…They are highly susceptible to environmental changes due to their interactions with surroundings (Ternus et al, 2011).…”

Qualidade Da Água Ao Longo Da Micro Bacia Hidrográfica Do Rio Catolé-Ba

“…Estes ecossistemas são altamente susceptíveis a mudanças ambientais por instituírem um ambiente aberto, onde bacias hidrográficas interagem com seu entorno imediato (Ternus et al, 2011). Atividades como irrigação, desmatamento, urbanização, lançamentos pontuais: domésticos e industriais, no entorno da bacia causam interferências negativas na qualidade das águas de um corpo hídrico (Sardinha et al, 2010).…”