1996), fitted to the measured moisture characteristic K([psi]) relationship Represented with the smoothed Brooks-Corey function; parameter values were derived from field measurements of hydraulic conductivity and the moisture characteristic Bypass flow Calibrated against measured infiltration for the Goodger rainfall simulator experiment Surface roughness and Parameter values derived from roughness depression storage measured using a profile meter before and after simulated or natural rainfall events.
APSIM-SWIM effectively contains the utility of the standalone version of SWIM, including the ability to accurately simulate the runoff hydrograph, depression storage of runoff water, and macroporosity and by-pass flow.
The model accurately simulated infiltration controls, mostly surface crusting and the impact of surface detention on runoff, once parameter values describing depression storage were optimised.
The rough treatment had 5% surface cover, had previously been cultivated across slope with a tractor-drawn chisel plough, and had received 27 mm of rainfall since cultivation, but furrows still contained substantial depression storage.
Volume of depression storage was calculated using a modified algorithm from Moore and Larson (1979) and was the volume held on the plot when runoff from the whole plot reached the outlet.
SWIM runs down the capacity of depression storage with cumulative rainfall to a minimum value at a specified rate.
Water inputs to the root zone include effective rainfall (the fraction of total rain that infiltrates the soil after losses to leaf interception, surface runoff and depression storage, and evaporation) and irrigation (vineyard only).
Effective rainfall: Fraction of total rain that infiltrates the soil after losses to leaf interception, surface runoff, depression storage and evaporation.
Water inputs to the root zone: Include effective rainfall (the fraction of total rain that infiltrates the soil after losses to leaf interception, surface runoff, depression storage, and evaporation) and irrigation (in vineyards only in this study).