Within-in flume sediment deposition in a forested catchment following wildfire and post-fire bench terracing, north-central Portugal

J.J. Keizer, M.A.S. Martins, S.A. Prats, S.R. Faria, O. González-Pelayo, A.I. Machado, M.E. Rial-Rivas, L.F. Santos, D. Serpa, M.E.T. Varela



Wildfires increase plot-scale soil erosion rates across the world. However, very few studies have monitored post-fire erosion losses at the catchment scale, especially in the Mediterranean region. The FIRECNUTS project was originally set out to address this research gap by selecting a recently burnt catchment and instrumenting its outlet with two flumes with maximum discharge capacities of 120 and 1700 l s-1. Six months after the fire, however, this experimental catchment was bench terraced by bulldozer. Furthermore, the smallest flume suffered from regular deposition of sediments from the onset of its construction. This study was therefore an attempt to explore whether quantifying this deposition of sediments could provide further insight into the sediment yield of a recently burnt and terraced catchment. To this end, the deposited sediments were removed and weighted on a total of 101 occasions during a three year period. The results revealed that: (i) the amounts of sediment deposited over the three hydrological years corresponded to relatively small erosion rates, varying between 0.030 and 0.046 Mg ha-1 yr-1; (ii) while bench terracing is generally viewed as a soil and water conservation technique, it did not produce a clear decrease in sediment deposition, as deposition per mm of streamflow was the same before and after terracing (0.8 kg mm-1); (iii) daily sediment deposition could be explained reasonably well by daily rainfall volume and maximum daily streamflow volume.



sediment deposition, sediment yield, wildfire, bench terracing,Portugal.

Full Text:



APHA (American Public Health Association) 1998.Total suspended solids dried at 105 degrees Celsius method 2540D. In: Standard Methods for the Examination of Water and Waste Water, 20th ed., Washington, DC, USA.

Cardoso, J.C., Bessa, M.T., Marado, M.B. 1971. Carta dos solos de Portugal (1:1,000,000). Serviço de Reconhecimento e de Ordenamento Agrário, Secretaria de Estado da Agricultura, Lisbon, Portugal.

Cardoso, J.C., Bessa, M.T., Marado, M.B. 1973.Carta dos solos de Portugal (1:1,000,000). Agronomia Lusitana 33, 461–602.

Cerdà, A. 1998. Changes in overland flow and infiltration after a rangeland fire in a Mediterranean shrubland. Hydrological Processes 12, 1031-1042.

Cerdà, A., Bodí, M.D. 2007. In: Mataix-Solera, J. (ed.): Incendios forestales, suelos y erosión hídrica, pp. 71-118. CEMACAM Font Roja-Alcoi.

Cerdà, A., Doerr, S.H. 2008. The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. CATENA 74, 256–263.

DRA-Centro (Direcção Regional do Ambiente do Centro) 1998. Plano de bacia hidrográfica do Rio Vouga, 1ª fase, Análise e diagnóstico da situação de referência, Análise biofísica, Anexos. Lisboa, Portugal.

DUDF (Direcção de Unidade de Defesa da Floresta) 2011. Relatório Anual de Áreas Ardidas e Ocorrências 2010. Autoridade Florestal Nacional, Lisboa.

Fernandéz-Raga, M., Fraile, R., Keizer, J.J., Varela, M.E.T., Castro, A., Palencia, C., Calvo, A.I., Koenders, J., Marques, R.L.C. 2010. The kinetic energy of rain measured with an optical disdrometer: An application to splash erosion. Atmospheric Research 96, 210-240.

Ferreira, A. de Brum 1978. Planaltos e montanhas do norte da Beira – estudo de geomorfologia. Centro de Estudos Geográficos, Lisbon, Portugal.

Ferreira, A.J.D., Coelho, C.O.A., Ritsema, C.J., Boulet, A.K., Keizer, J.J., 2008. Soil and water degradation processes in burned areas: lessons learned from a nested approach. CATENA 74, 273–85.

Inbar, M., Tamir, M., Wittenberg, L. 1998. Runoff and erosion processes after a forest fire

in Mount Carmel, a Mediterranean area. Geomorphology 24, 17–33.

Keeley, J.E. 2009. Fire intensity, fire severity and burn severity: A brief review and suggested usage. International Journal of Wildland Fire 18, 1, 116-126.

Lavabre, J., Martin, C. 1997. Impact d'un incendie de forêt sur l'hydrologie et l'érosion hydrique d'un petit bassin versant méditerranéan. Human Impact on Erosion and Sedimentation (Proceedings of Rabat Symposium S6, April 1997): IAHS Publication 245, pp. 39–47.

Leighton-Boyce, G., Doerr, S.H., Shakesby, R.A., Walsh, R.P.D. 2007. Quantifying the impact of soil water repellency on overland flow generation and erosion: a new approach using rainfall simulation and wetting agent on in situ soil. Hydrological Processes 21, 2337–2345.

Malvar M.C., Prats S.A., Nunes J.P., Keizer J.J. 2011. Post-fire overland flow generation and inter-rill erosion under simulated rainfall in two eucalypt stands in north-central Portugal. Environmental Research 111, 222-236.

Malvar M.C., Martins M.A., Nunes J.P., Robichaud P.R., Keizer J.J. 2013. Assessing the role of pre-fire ground preparation operations and soil water repellency in post-fire runoff and inter-rill erosion by repeated rainfall simulation experiments in Portuguese eucalypt plantations. CATENA 108, 69-83.

Martins M.A.S., Machado A. I., Serpa D., Prats S.A., Faria S.R., Varela M.E.T., Gonzalez-Pelayo O., Keizer J.J. 2013. Runoff and inter-rill erosion in a Maritime Pine and a eucalypt plantation following wildfire and terracing in north-central Portugal. Journal of Hydrology and Hydromechanics 61, 4, 261-269.

Mataix-Solera, J., Cerdà, A., Arcenegui, V., Jordán, A., Zavala, L.M. 2011. Fire effects on soil aggregation: a review. Earth-Science Reviews 109, 44–60.

Mayor, A.G., Bautista, S., Llovet, J., Bellot, J. 2007. Post-fire hydrological and erosional

responses of a Mediterranean landscape: seven years of catchment-scale dynamics. Catena 71, 68–75.

Pereira, J.M.C., Carreiras, J.M.B., Silva, J.M.N., Vasconcelos, M.J. 2006. Alguns conceitos básicos sobre os fogos rurais em Portugal. In: Pereira, J.S., Pereira, J.M.C., Rego, F.C., Silva, J.M.N., Silva, T.P. (Eds.): Incêndios Florestais em Portugal: Caracterização, Impactes e Prevenção, pp. 133–161. ISAPress, Lisboa.

Prats S.A., Malvar, M.C., Vieira, D.C.S,, MacDonald L.H., Keizer J.J. 2013 (in press). Effectiveness of hydro-mulching to reduce runoff and erosion in a recently burnt pine plantation in central Portugal. Land Degradation & Development (doi: 10.1002/ldr.2236).

Prats S.A., Martins, M.A.S., Malvar, M.C., Ben-Hur, M., Keizer, J.J. 2014. Polyacrylamide application versus forest residue mulching for reducing post-fire runoff and soil erosion. Science of the Total Environment 468-469, 464-474.

Razzetto, G.F. 2013. Impacts of terracing after wildfires on soil water and matter budgets under eucalypt plantations following an artificial terracing time series. MSc thesis, Technical University of Dresden, Germany.

Shakesby, R.A. 2011. Post-wildfire soil erosion in the Mediterranean: Review and future research directions. Earth-Science Reviews 105, 71–100.

Shakesby, R.A., Doerr, S.H. 2006.Wildfire as a hydrological and geomorphological agent. Earth-Science Reviews 74, 269–307.

SNIRH (Serviço Nacional de Informação dos Recursos Hídricos) 2011. On-line hydrometeorological data base (http://www.snirh.pt; accesses December 2011).

Sokal, R.R., Rohlf, F.J. 1981. Biometryseconded. W.H.Freeman and Company, New York, USA.

Varela M.E., Benito E., Keizer J.J. 2010. Wildfire effects on soil erodibility of woodlands in NW Spain. Land Degradation and Development 21, 75-82.

Verstraeten, G., Poesen, J. 2001. Variability of dry sediment bulk density between and within retention ponds and its impact on the calculation of sediment yields. Earth Surface Processes and Landforms 26, 375–394.

WRB 2006. World reference base for soil resources 2006. World Soil Resources Reports, 103. FAO, Rome.

DOI: http://dx.doi.org/10.18172/cig.2700


  • There are currently no refbacks.

© Universidad de La Rioja, 2013

ISSN 0211-6820

EISSN 1697-9540