Evidence of the effects of spatial heterogeneity of saturated hydraulic conductivity, Ks, and rainfall rate, r, on hydrologic response is given. Theoretical experiments were performed by using synthetic rainfall rates over a slope with a fine textured soil. Both Ks and r were assumed to be random variables with log-normal probability density function (pdf). Given the pdf of Ks and r, an extensive set of Monte Carlo simulations was utilized. For each realization the hydrograph formation at the slope outlet was described through a deterministic representation of the processes of infiltration and routing of surface runoff. Our results indicate that the spatial heterogeneity leads to increase the hydrological response. Furthermore, the total effect of the spatial variability of r and Ks is not additive, and in the case of very different values of the coefficient of variation of these two quantities, it can be reasonable to consider only the effects produced by the quantity with the larger coefficient.
Role of coupled spatial variability of rainfall and soil hydraulic properties on the hillslope hydrograph
MORBIDELLI, Renato;CORRADINI, Corrado;SALTALIPPI, Carla;
2002
Abstract
Evidence of the effects of spatial heterogeneity of saturated hydraulic conductivity, Ks, and rainfall rate, r, on hydrologic response is given. Theoretical experiments were performed by using synthetic rainfall rates over a slope with a fine textured soil. Both Ks and r were assumed to be random variables with log-normal probability density function (pdf). Given the pdf of Ks and r, an extensive set of Monte Carlo simulations was utilized. For each realization the hydrograph formation at the slope outlet was described through a deterministic representation of the processes of infiltration and routing of surface runoff. Our results indicate that the spatial heterogeneity leads to increase the hydrological response. Furthermore, the total effect of the spatial variability of r and Ks is not additive, and in the case of very different values of the coefficient of variation of these two quantities, it can be reasonable to consider only the effects produced by the quantity with the larger coefficient.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
