Geografie 1999, 104, 176-187

Modelling the subsurface flow component in the runoff recession phase by means of a linear and non-linear reservoir models

Jiří Stehlík

Oddělení experimentální hydrologie, Český hydrometeorologický ústav, Na Šabatce 17, 143 06 Praha 4, Czechia

The paper deals with the time variability of the subsurface water storage depletion. The analysis was carried out in a small experimental basin in the Jizera Mountains, Czech Republic. The research focused on the hydro graph falling limbs - recession curves - which were selected from daily runoff series using various selection criteria. These criteria include a requirement that a curve should represent subsurface flow which is not increased by surface runoff. The selected measured recession curves are modelled by means of the exponential and hyperbolical law of depletion. The time variability of the recession curves is quantified by the variability of the modelled recession parameters. 22 variables representing antecedent climate and runoff conditions as well as the conditions during the recession period were defined for the examination of possible causing factors of the recession curve time variability. The correlation analysis and the multivariate statistical methods were applied.