Small Plot Hydrology: I. Rainfall Infiltration And Depression Storage Determination
ABSTRACT Rainfall, interception by residue, infiltration, depression storage, detention storage, and runoff and the interactions among these hydrologic processes for small agricultural plots were mathematically represented by a continuity equation and a modified Philip-type infiltration equation. The objective of the model was the determination of rainfall infiltration and surface depression storage from rainfall, runoff, and other readily measured data from small tilled field plots. The model was applied and evaluated for many small plots which had received constant-rate simulated rainfall and whose surfaces had been prepared by moldboard plow, chisel plow, disk, or no-till operations, performed up-and-down slope or on the contour. The model could distinguish depression and detention storage processes from infiltration. Values for the model parameters were characteristic of their physical attributes. Computed infiltration and depression storage values adequately represented the expected effects that tillage and residue cover have on infiltration and depression storage.