Soil water infiltration evaluation from punctual to hillslope scales

Stormflow Response and “Effective” Hydraulic Conductivity of a Degraded Tropical Imperata Grassland Catchment as Evaluated With Two Infiltration Models

“…Cheng et al (2018) had to invoke an additional "macropore conductivity" on top of the "matrix K sat " determined by Hassler et al (2011). Indeed, point-measured K sat -values are often reported to be lower than the "block permeabilities" of whole hillslopes (Brooks et al, 2004;Chappell et al, 1998;Pirastru et al, 2017;Wen & Gomez-Hernandez, 1996) or the "effective" parameter values derived with catchment models (e.g., Beven, 1989;Blöschl & Sivapalan, 1995;Chappell et al, 1998;Mertens et al, 2005;Koppe et al, 2022). Apart from the presence of "soil pipes" (Chappell, 2010;Elsenbeer & Vertessy, 2000;Kinner & Stallard, 2004) not captured by point measurements, a further explanation of this discrepancy may include "runoff-runon" processes (Bonell & Williams, 1986), where local IOF generated on patches of low-permeability soil, re-infiltrates in more permeable patches on the way to the stream (cf.…”

“…(2019) to assess the degree of possible underestimation of the latter due to underrepresentation of larger soil macropores in small‐scale field measurements (cf. Chappell et al., 1998; Koppe et al., 2022).…”

“…Hence, our objectives were to: (a) test the appropriateness and relative performance of GA and SVI for describing storm runoff for a small catchment in a state of advanced surface degradation; (b) examine the temporal variability of the calibrated model parameters, and their relation with antecedent soil water content and rainfall characteristics; and (c) compare calibrated catchment-scale infiltration parameter values with the previous field measurements of K sat by Zhang, Bruijnzeel, Quiñones, et al (2019) to assess the degree of possible underestimation of the latter due to underrepresentation of larger soil macropores in small-scale field measurements (cf. Chappell et al, 1998;Koppe et al, 2022).…”