Abstract

MENDEZ, Guillermo José et al. Sediment Transfer from a Microbasin to an Urban Drainage Network. Tecnol. cienc. agua [online]. 2014, vol.5, n.5, pp.21-37. ISSN 2007-2422.

Little data exists on sediment generation and transport rates in urban areas. This is due to the complexity of the phenomenon and, in particular, its variability. Three factors are investigated in this article: (1) annual sediment rate generated in a micro-basin over three years, (2) determination of the precipitations resulting in the highest values and (3) how prior hydrological conditions in the basin affect the sediment load in runoff. A basin in the city of Resistencia, in Chaco, Argentina, was monitored (4.76 ha with residential use) from September 2009 to March 2010. A hydrological model was calibrated with the SWMM program 5.0 and the primary sediment curves were drawn. With this and daily precipitation data for the years 2007/2008, 2008/2009 and 2009/2010 the annual sediment load transported by urban runoff was obtained for the analysis period. These ranged from 0.8 to 1.40 t/ha. The highest values documented occurred from September to December of each year, during which 60% of the load was trasnported. It is concluded that there is a strong incidence of volume runoff of sediment loads, where the most impermeable areas generate large flows and, therefore, higher sediment loads than permeable areas. The results obtained were consistent with the measurements and, therefore, quantification of sediments in pluvial drainage in urban basins is feasible.

Keywords : Sediments; urban drainage; plain basins.