Uso do solo na Bacia Hidrográfica do rio Camboriú (SC) e sua influência sobre a qualidade da água




The watershed of the Camboriú River is located in the cities of Camboriú and Balneário Camboriú. With a length of around 40 kilometers, it drains an area of 200 km2. This paper aims to characterize the Camboriú River watershed by determining space-time variations of physical, chemical and biological parameters of superficial water, as well as the soil occupation, in its encompassing area. The PH, temperature, conductivity, turbidity, salinity, dissolved oxygen, particle material in suspension, chlorophyll parameters and nutrients were analyzed at 10 sample points during the period of 2001 and 2002, and at 11 points during 2005 and 2006. The noxiousness of the superficial water of the watershed was also verified. The samples include urban, urban-outlying areas, rural and natural regions. The chemical-physical parameters analyzed show more elevated values in the urban and urban-outlying areas. I also observed significant increase between the periods of 2001-2002 and 2005-2006. Vegetation occupies the greatest percentage of the area of the watershed soil, but its greatest volume is limited to sides and hills, part of this cover is related to eucalyptus and pine tree monoculture. The vegetation identified ciliary forests or riparians are most fragmented along the tributaries of Camboriú River itself. In comparison to surveys of soil use and occupation performed at the end of the 90s, it was verified that the expansion of the urban area (2,06%) and of the agriculture area (2,99%), is most due to the cultivation of irrigated rice. The toxicity tests done with the crustacean Daphnia magna reveal the absence of acute noxiousness at the points analyzed in the Camboriu river watershed. Based on the parameters and analyzed results at this paper, it was possible to classify the water bodies within Resolution 357/05 of CONAMA. In a general way, the sample points located in the urban and urban-outlying areas are classified as class III, while the other area are class I. The levels of trophic state were also calculated for the 11 sample points of the Camboriú river watershed. Sample point #1(next to the effluent of the water treatment station) is characterized as a hypereutrophic. Points #1,#2, #3 and #4 (urban and urbanoutlying areas) were characterized as eutrophic, therefore, the sample point #1 revealed values approaching to hypereutrophic state. The rural points are classified as mesotrophic, indicating waters with intermediate productivity, with some suspicions about their quality, but in acceptable levels. The natural points, as was expected, are classified oligotrophic. Clear water wellsprings, of low productivity, without restriction regarding the uses of water due to the presence of nutrients


uso do solo parâmetros físicoquímicos e biológicos watershed soil use camboriú river physical chemical and biological parameters oceanografia rio camboriú bacia hidrográfica

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