Coppola et al. (2026) Surface-cover controls on reference-to-actual evaporation in silty pyroclastic soils of Campania region, Italy: evidence from an 12-year lysimeter experiment

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-22
• Authors: L. Coppola, A. Reder[27], G. Rianna, A. Tarantino, L. Pagano
• DOI: 10.1016/j.ejrh.2026.103978

Research Groups

• Universit`a di Napoli Federico II, Dipartimento di Ingegneria Civile, Edile ed Ambientale (DICEA)
• Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici
• University of Strathclyde, Department of Civil and Environmental Engineering

Short Summary

This study investigates the effects of different surface cover conditions on reference-to-actual evaporation in silty pyroclastic soils using a 12-year lysimeter experiment. The results highlight substantial differences in potential evaporation among the investigated surface conditions and distinct forms of kr(θ), including a bilinear decay for the WEC associated with its capillary-barrier effect.

Objective

• Investigate the effects of different surface cover conditions on reference-to-actual evaporation in silty pyroclastic soils.
• Derive empirical functions for the FAO single-crop approach, namely the crop coefficient (kc) and the water-content reduction function (kr(θ)), for a non-plastic silty volcanic soil.

Study Configuration

• Spatial Scale: Local scale, with a focus on the Campania region in Italy.
• Temporal Scale: 12-year lysimeter experiment.

Methodology and Data

• Models used: FAO single-crop approach, including the dual crop coefficient approach and the single crop coefficient approach.
• Data sources: Lysimeter data from a 12-year experiment, including measurements of meteorological variables, soil hydraulic properties, and topsoil volumetric water content.

Main Results

• The results highlight substantial differences in potential evaporation among the investigated surface conditions (bare soil, grass-covered soil, and bare soil covered by a wooden ember cover).
• Distinct forms of kr(θ) were observed, including a bilinear decay for the WEC associated with its capillary-barrier effect.
• The calibrated parameters were used to develop predictive abaci for estimating monthly evaporation from atmospheric variables alone.

Contributions

• This study provides experimentally based estimates of both stages of the evaporation process (potential and actual fluxes) in silty pyroclastic soils under different surface cover conditions.
• The results contribute to the understanding of the effects of surface cover on reference-to-actual evaporation in these soils, which is essential for hydrological modelling, agricultural management, and slope-stability applications.

Funding

• This research was funded by the Universit`a di Napoli Federico II, Dipartimento di Ingegneria Civile, Edile ed Ambientale (DICEA), Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici, and University of Strathclyde.

Citation

@article{Coppola2026Surfacecover,
  author = {Coppola, L. and Reder[27], A. and Rianna, G. and Tarantino, A. and Pagano, L.},
  title = {Surface-cover controls on reference-to-actual evaporation in silty pyroclastic soils of Campania region, Italy: evidence from an 12-year lysimeter experiment},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103978},
  url = {https://doi.org/10.1016/j.ejrh.2026.103978}
}