Author(s): N. Nahar; Rao S. Govindaraju; Corrado Corradini; Renato Morbielli
Linked Author(s):
Keywords: Runon; Monte-Carlo simulations; Sediment discharge; Heterogeneous hillslopes
Abstract: During rainfall events, the runon process allows water from upstream, saturated areas to infiltrate into downstream regions where moisture deficit has not been satisfied. The goal of this study was to evaluate the role of runon process in estimating field-scale sediment discharge over hillslopes with spatially-varying infiltration properties. This was accomplished by performing Monte-Carlo realizations of saturated conductivity fields with varying properties to reflect different soil conditions. Numerical solutions were sought for flow and sediment transport processes for each realization, and field-scale ensemble averages and variances of sediment discharge hydrographs were obtained. Examination of results indicates that neglecting runon can cause serious errors in estimation of field-scale sediment discharges. It is observed that only when the rainfall intensity is much larger than the mean conductivity and when variance of the conductivity is very low that runon can be ignored for sediment discharge computations.
Year: 2007