Analysis of the Suspended solids transport in a stream located in the southwest of the Buenos Aires province, Argentina

The total suspended solids (TSS) concentration is a relevant parameter for stream management. A high content of TSS has a negative impact on the ecological habitats and the aquatic environment, and could also be a limitation for the exploitation of surface water. The determination of TSS concentration through water sampling and posterior laboratory analysis is a complex and economically expensive procedure. In this regard, turbidity arises as a useful surrogate measure that allows the indirect estimation of the TSS concentration in a simple and economically convenient way. In the context of a severely deteriorated water supply system, the Naposta Grande stream constitutes a valuable resource for human and industrial consumption in the City of Bahia Blanca. The general objective of the present investigation is to develop statistically based relations between the parameters involved in the suspended solids transport, in order to characterize this phenomenon through the measurement of variables of simple and straightforward field determination. The statistical relationship between the TSS concentration and turbidity and between discharge and solid flow rate was explored. In both regression analyses, the statistical correlation resulted highly significant, and therefore represent valid calibration tools for future solids transport modelling analysis and prediction as well as for sedimentological balances. A comparative analysis of the solids transport between the closure of the medium drainage basin and at the outer limit of the suburban area of Bahia Blanca City, suggests the existence of erosive processes affecting the stream bed and its margins at the section between both sites.