IWRA Proceedings

AbstractRiver basin water quality monitoring systems, essential activity for the water management, involves lots of variables to be evaluated in the sense of allocating operational and financial resources that makes it an optimized project. Some researches, however, are developed to establish the minimal networks for monitoring watersheds that turns viable it implementation, even in small basins. Design water quality network monitoring involves three major activities: selection of the water quality indicators; allocation of the sample’s points; and the frequency of sampling activity. The first step is well known, whereas the followings have been done based on the knowledge of the watershed and by try and error. These need to be more studied to make it systemize. To point out the step of choosing the frequency of the sampling activity, this paper aims to verify the influence of some sample’s frequencies for the quantification of the pollutant loads in the Descoberto River Watershed, Federal District - Brazil, regarding the objective of subsidizing the sample’s frequency definition in ungaged basins. The Descoberto River Watershed is an area of assorted land use as well as conservation practices, with increasing development in recent years. This watershed is also the main water supply source for the Federal District and, consequently, there is a strong interest on the impact assessment of increasing human activities over the river water quality. The comparison of different strategies of sampling frequency, established by the Water and Wastewater Company and the refined frequency of this study at the Descoberto River Watershed, shows its influence for the river pollutants quantification.