Monitoramento ambiental da Bacia Hidrográfica do Rio Caiabi, MT

Abstract

Monitoring of surface water quality of the Caiabi River was conducted in five sampling points for 12 consecutive months . The study site is located in the state of Mato Grosso, in the catchment area of the Amazonia Legal. The economic activities in the basin are predominantly agricultural. The parameters determined were: temperature, pH, DO, conductivity, turbidity, BOD, total coliform, fecal coliform, nitrite, nitrate, total nitrogen Kjeldahl, chlorophyll a, total non-filterable solids and total phosphorus, filterable solids, total solids. All sampling methodologies, transportation, preservation and analysis were performed according to the compendial procedures recommended by the Standard Methods for the Examination of Water and Wastewater, manuals of kits and manuals equipments. The results were compared to reference values established by CONAMA 357/2005. The WQI and the IET were determined. And, through statistical analysis, the seasonal and spatial variation during the monitoring was evaluated. Given these results, the most appropriate experimental design for the study site was defined, taking into account the difficulties and limitations inherent in environmental monitoring programs. The results indicate the existence of a potential degradation of water quality due to sediment yield in the basin. The results of the IQA classify water quality to optimal, with values between 63 and 91. The results indicate that the IET the risk of eutrophication in the basin remains low. Statistical analysis confirmed that there was no significant seasonal and spatial variation in the values of WQI. The data therefore suggest that the experimental design could be suitable for a single point along the stretch of the river, with a reduced frequency of sampling. There was no evidence the presence of point source pollution in river Caiabi. This allowed tracking raise important information for future actions in this and other similar basin. In determining the potential for deterioration, control measures can be defined, such as the proposition of improvements in soil conservation practices and greater control in the use of inputs.