<abstract xmlns="http://www.w3.org/1999/xhtml">The lateral saturated hydraulic conductivity, <italic>Ks,l</italic>, is the soil property that mostly governs subsurface flow in hillslopes. Determinations of <italic>Ks,l</italic> at the hillslope scale are expected to yield valuable information for interpreting and modeling hydrological processes since soil heterogeneities are functionally averaged in this case. However, these data are rare since the experiments are quite difficult and costly. In this investigation, that was carried out in Sardinia (Italy), large-scale determinations of <italic>Ks,l</italic> were done in two adjacent hillslopes covered by a Mediterranean maquis and grass, respectively, with the following objectives: i) to evaluate the effect of land use change on <italic>Ks,l</italic>, and ii) to compare estimates of <italic>Ks,l</italic> obtained under natural and artificial rainfall conditions. Higher <italic>Ks,l</italic> values were obtained under the maquis than in the grassed soil since the soil macropore network was better connected in the maquis soil. The lateral conductivity increased sharply close to the soil surface. The sharp increase of <italic>Ks,l</italic> started at a larger depth for the maquis soil than the grassed one. The <italic>Ks,l</italic> values estimated during artificial rainfall experiments agreed with those obtained during the natural rainfall periods. For the grassed site, it was possible to detect a stabilization of <italic>Ks,l</italic> in the upper soil layer, suggesting that flow transport capacity of the soil pore system did not increase indefinitely. This study highlighted the importance of the experimental determination of <italic>Ks,l</italic> at the hillslope scale for subsurface modeling, and also as a benchmark for developing appropriate sampling methodologies based on near-point estimation of <italic>Ks,l</italic>.</abstract>

The lateral saturated hydraulic conductivity, Ks,l, is the soil property that mostly governs subsurface flow in hillslopes. Determinations of Ks,l at the hillslope scale are expected to yield valuable information for interpreting and modeling hydrological processes since soil heterogeneities are functionally averaged in this case. However, these data are rare since the experiments are quite difficult and costly. In this investigation, that was carried out in Sardinia (Italy), large-scale determinations of Ks,l were done in two adjacent hillslopes covered by a Mediterranean maquis and grass, respectively, with the following objectives: i) to evaluate the effect of land use change on Ks,l, and ii) to compare estimates of Ks,l obtained under natural and artificial rainfall conditions. Higher Ks,l values were obtained under the maquis than in the grassed soil since the soil macropore network was better connected in the maquis soil. The lateral conductivity increased sharply close to the soil surface. The sharp increase of Ks,l started at a larger depth for the maquis soil than the grassed one. The Ks,l values estimated during artificial rainfall experiments agreed with those obtained during the natural rainfall periods. For the grassed site, it was possible to detect a stabilization of Ks,l in the upper soil layer, suggesting that flow transport capacity of the soil pore system did not increase indefinitely. This study highlighted the importance of the experimental determination of Ks,l at the hillslope scale for subsurface modeling, and also as a benchmark for developing appropriate sampling methodologies based on near-point estimation of Ks,l.

Subsurface flow and large-scale lateral saturated soil hydraulic conductivity in a Mediterranean hillslope with contrasting land uses

Dipartimento di Scienze Agrarie e Forestali

Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria – Unita di ricerca per i sistemi colturali degli ambienti caldo-aridi (CREA–SCA)

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The lateral saturated hydraulic conductivity, Ks,l, is the soil property that mostly governs subsurface flow in hillslopes. Determinations of Ks,l at the...

Subsurface flow and large-scale lateral saturated soil hydraulic conductivity in a Mediterranean hillslope with contrasting land uses

Published Online: Jul 22, 2017

Page range: 297 - 306

Received: Aug 09, 2016

Accepted: Nov 25, 2016

DOI: https://doi.org/10.1515/johh-2017-0006

Keywords
Subsurface runoff, Drain, Pore connectivity, Sprinkling experiments, Land use change, Maquis

© 2017 Mario Pirastru et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Subsurface flow and large-scale lateral saturated soil hydraulic conductivity in a Mediterranean hillslope with contrasting land uses

Published Online: Jul 22, 2017

Page range: 297 - 306

Received: Aug 09, 2016

Accepted: Nov 25, 2016

DOI: https://doi.org/10.1515/johh-2017-0006

KeywordsSubsurface runoff, Drain, Pore connectivity, Sprinkling experiments, Land use change, Maquis

© 2017 Mario Pirastru et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Subsurface runoff, Drain, Pore connectivity, Sprinkling experiments, Land use change, Maquis