Keywords
pitimbu, water quality, monitoring, benthic
Start Date
1-7-2010 12:00 AM
Abstract
Urbanization in developing countries has had a significant impact on water resources and the environment. Anthropogenic-related factors such as deforestation, uncontrolled urban occupation and the lack of sustainable measures have affected both the quantity and quality of water. The Pitimbu river watershed (126.7 km2) is located within the urban area of Natal, Brazil. The effects of urban occupation have recently been a concern to municipal authorities, since the Pitimbu is the main source of domestic water supply. In this paper authors analyze monitoring data, including the quantitative and qualitative water and sediment factors at the lowland portion of this river system. To this end, two transverse cross sections were established, 5.6 km apart. The monitoring survey included measurement of water discharge and biological sediment analysis over a period of 11 months (Nov 2007 to Oct 2008). Water discharge varied from 0.62 m3s-1 (dry season) to 10.61 m3s-1 (rainy season). Discharge rates were used to fit Depuit-Boussinesq baseflow recession equation parameters. The recession constant (0.8) revealed strong river aquifer interaction. Such interaction explains the increase in discharge between the two sections by a factor of 1.98. Increasing sediment input to the river channel has occurred during high magnitude events, resulting in channel sedimentation. Biological sediment analysis revealed both the absence of sensitive benthic species (Corduliidae) and abundance of resistant benthic species (M. Tuberculata), indicating the occurrence of heavy metal contamination.
Pitimbu River Lowland Portion Water and Sediment Monitoring Data, Natal Brazil
Urbanization in developing countries has had a significant impact on water resources and the environment. Anthropogenic-related factors such as deforestation, uncontrolled urban occupation and the lack of sustainable measures have affected both the quantity and quality of water. The Pitimbu river watershed (126.7 km2) is located within the urban area of Natal, Brazil. The effects of urban occupation have recently been a concern to municipal authorities, since the Pitimbu is the main source of domestic water supply. In this paper authors analyze monitoring data, including the quantitative and qualitative water and sediment factors at the lowland portion of this river system. To this end, two transverse cross sections were established, 5.6 km apart. The monitoring survey included measurement of water discharge and biological sediment analysis over a period of 11 months (Nov 2007 to Oct 2008). Water discharge varied from 0.62 m3s-1 (dry season) to 10.61 m3s-1 (rainy season). Discharge rates were used to fit Depuit-Boussinesq baseflow recession equation parameters. The recession constant (0.8) revealed strong river aquifer interaction. Such interaction explains the increase in discharge between the two sections by a factor of 1.98. Increasing sediment input to the river channel has occurred during high magnitude events, resulting in channel sedimentation. Biological sediment analysis revealed both the absence of sensitive benthic species (Corduliidae) and abundance of resistant benthic species (M. Tuberculata), indicating the occurrence of heavy metal contamination.
