This paper presents a large scale hydrological model for the Fitzroy Basin using the MIKE 11 NAM modelling system. This model simulates the rainfall runoff processes for the three different and interrelated storages which are surface storage, root zone storage and groundwater storage. The parameters of such model cannot be obtained directly from measurable quantities of catchment characteristics. Hence model calibration is required to get the model parameters. Manual calibration is very time consuming and it only focuses on a single objective function. Thus tradeoff exists between the different objectives. For this study, an automatic calibration was done considering the four multiple objectives and obtained the optimal values of the model parameters for each catchment. The simulated and observed discharge hydrographs show a reasonable good match for each sub-catchment. Moreover model reliability was evaluated using the statistical methods Index of Agreement (IA) and Efficiency Index (EI). The IA and EI obtained 0.821-0.951 and 0.849-0.961 for different sub-catchments

A distributed 1D rainfall–runoff model is presented. It consists of the Saint Venant continuity and momentum equations for overland flow and a modified Green-Ampt model for the infiltration on railway embankment steep slopes. The model is applied to adjacent 10-m-wide erosion control experimental plots with different percentages of grass cover. A relationship between the 2-day antecedent rainfall and initial moisture content was established and used to predict the saturated hydraulic conductivity (Ks). Average values of Ks for 0, 50 and 100% grass cover were found to be 0.1, 1.19 and 2.56 mm/h, respectively. For the majority of cases, the model simulated runoff with acceptable accuracy, 68% having Nash-Sutcliffe efficiency (NSE) values above 0.50. The average NSE value varied between 0.60 and 0.80, with 0% grass-covered plots yielding the highest values. As expected, the runoff volume decreased with increasing percentage of grass cover. Citation Sajjan, A.K., Gyasi-Agyei, Y., and Sharma, R.H., 2013. Rainfall–runoff modelling of railway embankment steep slopes. Hydrological Sciences Journal, 58 (5), 1162–1176. Editor D. Koutsoyiannis