Long term discharge simulation through a geomorphological model

Flow duration curve estimation must be performed on the basis of continuous rainfall-runoff simulations. In ungauged basins, a under-parameterised model is needed to reduce the uncertainty of the results. In this paper a geomorphological model based on a width function (WFIUH) was used to simulate low flows in a mean-sized basin in Central Italy. The WFIUH model [9]introduces a new approachto the curvenumber method and was used to evaluate the stream-flow for hourly event representation. The aim of this work is to evaluate the behaviour of the WFIUH model for long term simulation and then to compare the standard curve number approach to the curve number method implemented in the WFIUH model. To predict the behaviour of catchments for a long term, to know the response of catchments in different seasons or in different years, it is necessary to improve the model and to identify a new method for calculating base-flow. To obtain these results, it is necessary to separate base-flow and stream-flow, simulate the two contributions and build a unique series of values that reproduces the answer of the basin to different rainfalls during the year to estimate the low flow during a dry period. The model can also be used in ungauged basins because a unique parameter is used. © 2013 AIP Publishing LLC.