Longitudinal scattering coefficient obtained by hydroacoustic measurement and by conservative tracer

Abstract

The objective of the present work was to determine the value of the longitudinal dispersion coefficient (DL) of the Chicamtoltina stream (Alta Gracia) by means of two different techniques, in order to compare the values obtained. The first technique consisted of applying a developed formula that includes a detailed description of hydrodynamic parameters obtained by gauging with a hydroacoustic instrument, while the second technique consisted of injecting a conservative tracer, using the same approach as the non-ideal chemical reactor theory of flow with dispersion. This work was carried out at low flow conditions (dry period) and at high flow conditions (wet period). It was found that, either for high flow or low flow, the values of the dispersion coefficient obtained by both techniques have good agreement, fitting better in the dry period than in the wet period. Due to the fact that frequent gauging campaigns are carried out in this stream, it is concluded that with similar flow characteristics and morphology of the section, the gauging data can be used to determine the DL coefficient, in order to incorporate reliable data that can be applied to pollutant transport models.