IWRA Proceedings

AbstractRiver basin water monitoring systems have great importance to identify water quality patterns in areas where they are not known, as well as to determine sources and pollutant loads. It is also an essential activity for the water management and involves lots of variables to be evaluated regarding the allocation of operational and financial resources with the purpose of optimizing the work. Some researches, however, have been developed to establish the minimal networks needed for monitoring watersheds, what turns viable its implementation even in small basins. The design of monitoring water quality networks involves three major activities: selection of water quality indicators, allocation of the sample’s points and frequency of sampling activity. The first step is the most known, whereas the following two are done by the knowledge of the watershed, by trial and error. Due to this evidence they need to be more explored in order to make it systemized. Considering the step of choosing the frequency of sampling activity, this paper aims to verify the influence of some sample’s frequency to the quantification of pollutant loads in the Descoberto River Watershed, Federal District - Brazil, in view of a future objective of subsidizing the frequency of sample in ungaged basins. The Descoberto River Watershed is an area of assorted land use as well as the conservation practices, with increasing development in recent years. This watershed is also the main water supply source in Federal District and, consequently, there is a strong interest in impact assessment of the increasing human activities in river water quality. The comparison of the different strategies of sampling, in terms of frequency, established by the Water and Wastewater Company, after years of operation, and the refined frequency of this study at the Descoberto River Watershed, have shown their influence on the quantification of the river pollutants.