A test of water pouring height and run intermittence effects on single-ring infiltration rates

Abstract

Assessing how the infiltration process depends on the water impact energy improves interpretation of hydrological processes. Impact energies vary with the height of water pouring; that is, the distance between the water delivery point and the soil surface. The effects of the height of water pouring on infiltration in an initially near saturated soil can be tested in the field by two repeated Beerkan infiltration runs separated by a short pause (30 min) and using both low (non-perturbing) and high (perturbing) heights of water application. The double two-stage Beerkan run methodology was applied in two soils. The infiltration rate at the end of the perturbing stage of the experiment was 0.2–0.3 (sandy-loam soil) and 0.15 (loam soil) times that obtained with the initial, nonperturbing stage whereas, without any perturbing effect, infiltration rates at the end of the second run were 0.5 times those at the end of the first run. Therefore, the methodology distinguished between a decrease in infiltration rate due to water redistribution during the pause and that attributable to soil surface perturbation. Maintaining a small depth of water (10 mm) on the infiltration surface was not an alternative to the classical Beerkan run for the non-perturbing stage of the experiment since two times higher infiltration rates were measured with a greater hydrostatic pressure. In conclusion, the relationship between infiltration into an initially near saturated soil and the energy of the applied water can be determined directly in the field at any time with a simple and parsimonious experiment. This circumstance could improve soil hydraulic characterization for interpreting and simulating hydrological processes.