Implications of scale, slope, tillage operation and direction in the estimation of surface depression storage. Soil & Tillage Research, v.111, p.142-153, 2011.
Roughness indices for estimation of depression storage capacity of tilled soil surfaces.
Catchment characteristics are catchment area (A), catchment width (W), average slope ([S.sub.o]), percentage of the impervious area (% imp), surface depression storage, and surface roughness.
0.3 mm for [D.sub.imp], 2.5 mm for [D.sub.per], 25% for zero depression storage, 0.01 for surface roughness coefficient for overland flow on impervious portion, 0.3 for surface roughness coefficient for overland flow on pervious portion, etc.
The depression storage used in this model is the average of dry and wet weather, which is determined as 0.7 mm for the basin.
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).
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. Land slope is 2.5-2.9%.
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.
The model works with basic hydrologic parameters such as catchment area, percent of impervious area, depression storage for impervious areas, and the Soil Conservation Service (SCS) number for pervious areas.
That is, longer storm events tend to minimize the effects of depression storage and to increase runoff from previous areas.