Qualidade Ambiental das Águas Superficiais da Bacia Hidrográfica do Ribeirão da Areia, Municípios de Buriti Alegre e Morrinhos, Goiás

Abstract

The present work has the objective of diagnose the environmental quality of surface waters in different portions of the Ribeirão da Areia Watershed, located in the south of the State of Goiás, being an important food producer in Brazil. For this, were outlined procedures and techniques for sampling water quality, by means of the collection and analysis of samples of 10 points during the dry and rainy periods, spatially distributed in the watershed, in order to contemplate high, medium and low courses of the main tributaries. In laboratory, were performed procedures according to SMEWW - Standard Methods for the Examination of Water and Wastewater. The results of physico-chemical and microbiological variables were compared to the limits established by CONAMA Resolution No. 357/2005 for Class 2 waters. The weighted product of the calculation between these variables generated the WQI - Water Quality Index. During the field work, the RAP – Rapid Assessment of Rivers Protocol was also applied. The application of these methods allowed the understanding of the environmental framework of the waters and their respective environments, allowing the identification of possible changes that impacted the quality of water resources. Were used geoprocessing methods to the spatialization of informations. During the dry season, the results showed a variation of the WQI between 63.01 and 89.95, being only one point with classification of waters in "good" and the others in "optimal", according to the standard adopted for the State of Goiás. During the rainy season, the results showed indices varying between 62.18 and 85.77, being three points in good condition and the others in evaluated in "optimal". Was also evidenced the necessity of framing the water bodies in the respective classes of fresh waters of CONAMA Resolution No. 357/2005. The diagnostic of environmental adequacy allowed the identification of irregularities of the analyzed points against what is required by the Forest Code, specifically to the maintenance of permanent preservation areas. Almost in its entirety, the analyzed points, besides not maintaining the necessary width, presented problems also regarding the phytophysiognomic density. The forms of use and occupation had a significant role about this reality, especially those that are more present, such as pasture and agriculture. It is necessary that such researches be performed periodically, together with action plans of competent bodies, allowing to evaluate and identify environmental fragilities, enabling greater effectiveness in the performance of public power in the face of recurring problems.