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International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire
RESEARCH ARTICLE

Can pore-clogging by ash explain post-fire runoff?

Cathelijne R. Stoof A B I , Anouk I. Gevaert A C D , Christine Baver A , Bahareh Hassanpour A , Verónica L. Morales E F , Wei Zhang G , Deborah Martin H , Shree K. Giri A and Tammo S. Steenhuis A
+ Author Affiliations
- Author Affiliations

A Department of Biological and Environmental Engineering, Riley Robb Hall, Cornell University, Ithaca, NY 14853, USA.

B Soil Geography and Landscape Group, Wageningen University, PO Box 47, 6700 AA Wageningen, the Netherlands.

C Hydrology and Quantitative Water Management Group, Wageningen University, PO Box 47, 6700 AA Wageningen, the Netherlands.

D Earth and Climate Cluster, Department of Earth Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.

E SIMBIOS Centre, Abertay University, Dundee DD1 1HG, United Kingdom.

F Institute of Environmental Engineering, ETH Zürich, Zürich 8093, Switzerland.

G Department of Plant, Soil and Microbial Sciences, Environmental Science and Policy Program, Michigan State University, 1066 Bogue Street, East Lansing, MI 48824, USA.

H United States Geological Survey, 3215 Marine Street (E147), Boulder, CO 80303-1066, USA.

I Corresponding author. Email: cathelijne.stoof@wur.nl

International Journal of Wildland Fire 25(3) 294-305 https://doi.org/10.1071/WF15037
Submitted: 6 February 2015  Accepted: 21 October 2015   Published: 20 January 2016

Abstract

Ash plays an important role in controlling runoff and erosion processes after wildfire and has frequently been hypothesised to clog soil pores and reduce infiltration. Yet evidence for clogging is incomplete, as research has focussed on identifying the presence of ash in soil; the actual flow processes remain unknown. We conducted laboratory infiltration experiments coupled with microscope observations in pure sands, saturated hydraulic conductivity analysis, and interaction energy calculations, to test whether ash can clog pores (i.e. block pores such that infiltration is hampered and ponding occurs). Although results confirmed previous observations of ash washing into pores, clogging was not observed in the pure sands tested, nor were conditions found for which this does occur. Clogging by means of strong attachment of ash to sand was deemed unlikely given the negative surface charge of the two materials. Ponding due to washing in of ash was also considered improbable given the high saturated conductivity of pure ash and ash–sand mixtures. This first mechanistic step towards analysing ash transport and attachment processes in field soils therefore suggests that pore clogging by ash is unlikely to occur in sands. Discussion is provided on other mechanisms by which ash can affect post-fire hydrology.

Additional keywords: hydraulic conductivity, infiltration, wildland fire ash.


References

Arya LM, Leij FJ, van Genuchten MT, Shouse PJ (1999) Scaling parameter to predict the soil water characteristic from particle-size distribution data. Soil Science Society of America Journal 63, 510–519.
Scaling parameter to predict the soil water characteristic from particle-size distribution data.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXks1ajtLs%3D&md5=0fa17ebcff01c882c52d6e4a1c0b76fbCAS |

Audry S, Akerman A, Riotte J, Oliva P, Marechal J-C, Fraysse F, Pokrovsky OS, Braun J-J (2014) Contribution of forest fire ash and plant litter decay on stream dissolved composition in a sub-humid tropical watershed (Mule Hole, southern India). Chemical Geology 372, 144–161.
Contribution of forest fire ash and plant litter decay on stream dissolved composition in a sub-humid tropical watershed (Mule Hole, southern India).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXksleit7g%3D&md5=43906ffdaa492753040a8672e3456ad2CAS |

Badía D, Martí C, Aguirre AJ, Aznar JM, González-Pérez JA, De la Rosa JM, León J, Ibarra P, Echeverría T (2014) Wildfire effects on nutrients and organic carbon of a Rendzic Phaeozem in NE Spain: changes at cm-scale topsoil. Catena 113, 267–275.
Wildfire effects on nutrients and organic carbon of a Rendzic Phaeozem in NE Spain: changes at cm-scale topsoil.Crossref | GoogleScholarGoogle Scholar |

Baker RS, Hillel D (1990) Laboratory tests of a theory of fingering during infiltration into layered soils. Soil Science Society of America Journal 54, 20–30.
Laboratory tests of a theory of fingering during infiltration into layered soils.Crossref | GoogleScholarGoogle Scholar |

Balfour VN, Woods SW (2013) The hydrological properties and the effects of hydration on vegetative ash from the Northern Rockies, USA. Catena 111, 9–24.
The hydrological properties and the effects of hydration on vegetative ash from the Northern Rockies, USA.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXht1CgsbnJ&md5=4cc8d6800f70aecc094a73a0e57065dfCAS |

Balfour VN, Doerr SH, Robichaud PR (2014) The temporal evolution of wildfire ash and implications for post-fire infiltration. International Journal of Wildland Fire 23, 733–745.
The temporal evolution of wildfire ash and implications for post-fire infiltration.Crossref | GoogleScholarGoogle Scholar |

Baveye P, Vandevivere P, Hoyle BL, DeLeo PC, de Lozada DS (1998) Environmental impact and mechanisms of the biological clogging of saturated soils and aquifer materials. Critical Reviews in Environmental Science and Technology 28, 123–191.
Environmental impact and mechanisms of the biological clogging of saturated soils and aquifer materials.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXjtlemsrw%3D&md5=9d2cca43329b25144572d063e123c18fCAS |

Blazejewski R, Murat-Blazejewska S (1997) Soil clogging phenomena in constructed wetlands with subsurface flow. Water Science and Technology 35, 183–188.
Soil clogging phenomena in constructed wetlands with subsurface flow.Crossref | GoogleScholarGoogle Scholar |

Bodí MB, Mataix-Solera J, Doerr SH, Cerdà A (2011) The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content. Geoderma 160, 599–607.
The wettability of ash from burned vegetation and its relationship to Mediterranean plant species type, burn severity and total organic carbon content.Crossref | GoogleScholarGoogle Scholar |

Bodí MB, Doerr SH, Cerdà A, Mataix-Solera J (2012) Hydrological effects of a layer of vegetation ash on underlying wettable and water-repellent soil. Geoderma 191, 14–23.
Hydrological effects of a layer of vegetation ash on underlying wettable and water-repellent soil.Crossref | GoogleScholarGoogle Scholar |

Bodí MB, Martin DA, Balfour VN, Santín C, Doerr SH, Pereira P, Cerdà A, Mataix-Solera J (2014) Wildland fire ash: production, composition and ecohydrogeomorphic effects. Earth-Science Reviews 130, 103–127.
Wildland fire ash: production, composition and ecohydrogeomorphic effects.Crossref | GoogleScholarGoogle Scholar |

Bond WJ (1986) Illuvial band formation in a laboratory column of sand. Soil Science Society of America Journal 50, 265–267.
Illuvial band formation in a laboratory column of sand.Crossref | GoogleScholarGoogle Scholar |

Bradford SA, Torkzaban S (2008) Colloid transport and retention in unsaturated porous media: a review of interface-, collector-, and pore-scale processes and models. Vadose Zone Journal 7, 667–681.
Colloid transport and retention in unsaturated porous media: a review of interface-, collector-, and pore-scale processes and models.Crossref | GoogleScholarGoogle Scholar |

Bradford SA, Morales VL, Zhang W, Harvey RW, Packman AI, Mohanram A, Welty C (2013) Transport and fate of microbial pathogens in agricultural settings. Critical Reviews in Environmental Science and Technology 43, 775–893.
Transport and fate of microbial pathogens in agricultural settings.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhvVaku73L&md5=2e681901eff07bc744429ae759de31c0CAS |

Cai J, Yu B (2011) A discussion of the effect of tortuosity on the capillary imbibition in porous media. Transport in Porous Media 89, 251–263.
A discussion of the effect of tortuosity on the capillary imbibition in porous media.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXpvFynt7w%3D&md5=ce85d9edf5fa69aca5bb8eb795c1f10bCAS |

Cerdà A, Doerr SH (2008) The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena 74, 256–263.
The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period.Crossref | GoogleScholarGoogle Scholar |

Cerdà A, Robichaud P (Eds) (2009) Fire effects on soils and restoration strategies. In ‘Land reconstruction and management series, Vol. 5’. (Science Publishers: Enfield, NH)10.1201/9781439843338-F

Costa MR, Calvão AR, Aranha J (2014) Linking wildfire effects on soil and water chemistry of the Marão River watershed, Portugal, and biomass changes detected from Landsat imagery. Applied Geochemistry 44, 93–102.
Linking wildfire effects on soil and water chemistry of the Marão River watershed, Portugal, and biomass changes detected from Landsat imagery.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhs1ehtLbM&md5=b4248c0346ba79be82d5a638af504616CAS |

Dathe A, Zevi Y, Richards BK, Gao B, Parlange J-Y, Steenhuis TS (2014) Functional models for colloid retention in porous media at the triple line. Environmental Science and Pollution Research International 21, 9067–9080.
Functional models for colloid retention in porous media at the triple line.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXhsVSjurfM&md5=93257c94b7b371bda011dcb97bf44ec8CAS | 24234754PubMed |

De Vries J (1972) Soil filtration of wastewater effluent and the mechanism of pore clogging. Journal – Water Pollution Control Federation 44, 565–573.

Dlapa P, Bodí MB, Mataix-Solera J, Cerdà A, Doerr SH (2013) FT-IR spectroscopy reveals that ash water repellency is highly dependent on ash chemical composition. Catena 108, 35–43.
FT-IR spectroscopy reveals that ash water repellency is highly dependent on ash chemical composition.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXosFaju7k%3D&md5=6defa0236beedc361f6a5f0eff8b6725CAS |

Dunkerley D (2008) Rain event properties in nature and in rainfall simulation experiments: a comparative review with recommendations for increasingly systematic study and reporting. Hydrological Processes 22, 4415–4435.
Rain event properties in nature and in rainfall simulation experiments: a comparative review with recommendations for increasingly systematic study and reporting.Crossref | GoogleScholarGoogle Scholar |

Ebel BA (2012) Wildfire impacts on soil-water retention in the Colorado Front Range, United States. Water Resources Research 48, W12515
Wildfire impacts on soil-water retention in the Colorado Front Range, United States.Crossref | GoogleScholarGoogle Scholar |

Ebel BA, Moody JA, Martin DA (2012) Hydrologic conditions controlling runoff generation immediately after wildfire. Water Resources Research 48, WR011470
Hydrologic conditions controlling runoff generation immediately after wildfire.Crossref | GoogleScholarGoogle Scholar |

Etiégni L, Campbell AG (1991) Physical and chemical characteristics of wood ash. Bioresource Technology 37, 173–178.
Physical and chemical characteristics of wood ash.Crossref | GoogleScholarGoogle Scholar |

Fernández Marcos ML, Buurman P, Meijer EL (1998) Role of organic matter and sesquioxides on variable charge of three soils from Galicia, Spain. Communications in Soil Science and Plant Analysis 29, 2441–2457.
Role of organic matter and sesquioxides on variable charge of three soils from Galicia, Spain.Crossref | GoogleScholarGoogle Scholar |

Fetter CW (2000) ‘Applied hydrogeology.’ (Prentice Hall: Upper Saddle River, NJ)

Fox DM, Darboux F, Carrega P (2007) Effects of fire-induced water repellency on soil aggregate stability, splash erosion, and saturated hydraulic conductivity for different size fractions. Hydrological Processes 21, 2377–2384.

Gabet EJ, Sternberg P (2008) The effects of vegetative ash on infiltration capacity, sediment transport, and the generation of progressively bulked debris flows. Geomorphology 101, 666–673.
The effects of vegetative ash on infiltration capacity, sediment transport, and the generation of progressively bulked debris flows.Crossref | GoogleScholarGoogle Scholar |

Giglio L, Randerson JT, van der Werf GR, Kasibhatla PS, Collatz GJ, Morton DC, DeFries RS (2010) Assessing variability and long-term trends in burned area by merging multiple satellite fire products. Biogeosciences 7, 1171–1186.
Assessing variability and long-term trends in burned area by merging multiple satellite fire products.Crossref | GoogleScholarGoogle Scholar |

Goforth BR, Graham RC, Hubbert KR, Zanner CW, Minnich RA (2005) Spatial distribution and properties of ash and thermally altered soils after high-severity forest fire, southern California. International Journal of Wildland Fire 14, 343–354.
Spatial distribution and properties of ash and thermally altered soils after high-severity forest fire, southern California.Crossref | GoogleScholarGoogle Scholar |

Hubbert KR, Preisler HK, Wohlgemuth PM, Graham RC, Narog MG (2006) Prescribed burning effects on soil physical properties and soil water repellency in a steep chaparral watershed, southern California, USA. Geoderma 130, 284–298.
Prescribed burning effects on soil physical properties and soil water repellency in a steep chaparral watershed, southern California, USA.Crossref | GoogleScholarGoogle Scholar |

Johnson PR (1999) A comparison of streaming and microelectrophoresis methods for obtaining the ζ potential of granular porous media surfaces. Journal of Colloid and Interface Science 209, 264–267.
A comparison of streaming and microelectrophoresis methods for obtaining the ζ potential of granular porous media surfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXjtFKjtA%3D%3D&md5=882df83262e56b5b998c6af267f6ecafCAS | 9878164PubMed |

Kinner DA, Moody JA (2010) Spatial variability of steady-state infiltration into a two-layer soil system on burned hillslopes. Journal of Hydrology 381, 322–332.
Spatial variability of steady-state infiltration into a two-layer soil system on burned hillslopes.Crossref | GoogleScholarGoogle Scholar |

Kretzschmar R, Sticher H (1997) Transport of humic-coated iron oxide colloids in a sandy soil: influence of Ca2+ and trace metals. Environmental Science & Technology 31, 3497–3504.
Transport of humic-coated iron oxide colloids in a sandy soil: influence of Ca2+ and trace metals.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXmvVamtL0%3D&md5=5fbe339780d125a567a4a9a80b348a94CAS |

Kutiel P, Lavee H, Segev M, Benyamini Y (1995) The effect of fire-induced surface heterogeneity on rainfall–runoff–erosion relationships in an eastern Mediterranean ecosystem, Israel. Catena 25, 77–87.
The effect of fire-induced surface heterogeneity on rainfall–runoff–erosion relationships in an eastern Mediterranean ecosystem, Israel.Crossref | GoogleScholarGoogle Scholar |

Larsen IJ, MacDonald LH, Brown E, Rough D, Welsh MJ, Pietraszek JH, Libohova Z, de Dios Benavides-Solorio J, Schaffrath K (2009) Causes of post-fire runoff and erosion: water repellency, cover, or soil sealing? Soil Science Society of America Journal 73, 1393–1407.
Causes of post-fire runoff and erosion: water repellency, cover, or soil sealing?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXos1Ggtr8%3D&md5=a71774f8ae470afcb00e70fcf47f8fb8CAS |

León J, Bodí MB, Cerdà A, Badía D (2013) The contrasted response of ash to wetting: the effects of ash type, thickness and rainfall events. Geoderma 209–210, 143–152.
The contrasted response of ash to wetting: the effects of ash type, thickness and rainfall events.Crossref | GoogleScholarGoogle Scholar |

Mallik AU, Gimingham CH, Rahman AA (1984) Ecological effects of heather burning. I. Water infiltration, moisture retention and porosity of the surface soil. Journal of Ecology 72, 767–776.
Ecological effects of heather burning. I. Water infiltration, moisture retention and porosity of the surface soil.Crossref | GoogleScholarGoogle Scholar |

Martin DA, Moody JA (2001) Comparison of soil infiltration rates in burned and unburned mountainous watersheds. Hydrological Processes 15, 2893–2903.
Comparison of soil infiltration rates in burned and unburned mountainous watersheds.Crossref | GoogleScholarGoogle Scholar |

Mataix-Solera J, Cerdà A, Arcenegui V, Jordán A, Zavala LM (2011) Fire effects on soil aggregation: a review. Earth-Science Reviews 109, 44–60.
Fire effects on soil aggregation: a review.Crossref | GoogleScholarGoogle Scholar |

McDowell‐Boyer LM, Hunt JR, Sitar N (1986) Particle transport through porous media. Water Resources Research 22, 1901–1921.
Particle transport through porous media.Crossref | GoogleScholarGoogle Scholar |

Meixner T, Wohlgemuth PM (2003) Climate variability, fire, vegetation recovery, and watershed hydrology. In ‘First interagency conference on research in the watersheds’, 27–30 October 2003, Benson, AZ. (Eds KG Renard, SA McElroy, WJ Gburek, EH Canfield, RL Scott) (USDA Agricultural Research Service: Benson, AZ)

Miller BA, Schaetzl RJ (2012) Precision of soil particle size analysis using laser diffractometry. Soil Science Society of America Journal 76, 1719–1727.
Precision of soil particle size analysis using laser diffractometry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhsVOmsr%2FN&md5=194428e0ab754993b75aefbb3e23ed0eCAS |

Moody JA, Ebel BA (2012) Hyper-dry conditions provide new insights into the cause of extreme floods after wildfire. Catena 93, 58–63.
Hyper-dry conditions provide new insights into the cause of extreme floods after wildfire.Crossref | GoogleScholarGoogle Scholar |

Moody JA, Martin DA (2001) Initial hydrologic and geomorphic response following a wildfire in the Colorado Front Range. Earth Surface Processes and Landforms 26, 1049–1070.
Initial hydrologic and geomorphic response following a wildfire in the Colorado Front Range.Crossref | GoogleScholarGoogle Scholar |

Moody JA, Shakesby RA, Robichaud PR, Cannon SH, Martin DA (2013) Current research issues related to post-wildfire runoff and erosion processes. Earth-Science Reviews 122, 10–37.
Current research issues related to post-wildfire runoff and erosion processes.Crossref | GoogleScholarGoogle Scholar |

Morales VL, Gao B, Steenhuis TS (2009) Grain surface-roughness effects on colloidal retention in the vadose zone. Vadose Zone Journal 8, 11–20.
Grain surface-roughness effects on colloidal retention in the vadose zone.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtl2qurY%3D&md5=f0dbff68526fb421e6f75a71334828aaCAS |

Munsell Color (1975) ‘Munsell soil color charts.’ (Macbeth, a division of Kollmorgen Corporation: Baltimore, MD)

Nyman P, Sheridan G, Lane PNJ (2010) Synergistic effects of water repellency and macropore flow on the hydraulic conductivity of a burned forest soil, south-east Australia. Hydrological Processes 24, 2871–2887.
Synergistic effects of water repellency and macropore flow on the hydraulic conductivity of a burned forest soil, south-east Australia.Crossref | GoogleScholarGoogle Scholar |

Nyman P, Sheridan GJ, Smith HG, Lane PNJ (2014) Modeling the effects of surface storage, macropore flow and water repellency on infiltration after wildfire. Journal of Hydrology 513, 301–313.
Modeling the effects of surface storage, macropore flow and water repellency on infiltration after wildfire.Crossref | GoogleScholarGoogle Scholar |

Onda Y, Dietrich WE, Booker F (2008) Evolution of overland flow after a severe forest fire, Point Reyes, California. Catena 72, 13–20.
Evolution of overland flow after a severe forest fire, Point Reyes, California.Crossref | GoogleScholarGoogle Scholar |

Pereira P, Úbeda X, Martin D, Mataix-Solera J, Guerrero C (2011) Effects of a low-severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the north-east of the Iberian Peninsula. Environmental Research 111, 237–247.
Effects of a low-severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the north-east of the Iberian Peninsula.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtlKqsLk%3D&md5=d99c00619e2d61353b19021af22ca7faCAS | 20869047PubMed |

Pereira P, Úbeda X, Martin DA (2012) Fire severity effects on ash chemical composition and water-extractable elements. Geoderma 191, 105–114.
Fire severity effects on ash chemical composition and water-extractable elements.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhs1Gqsb7M&md5=8e9c57b0a625a85620c1811667d6959eCAS |

Pereira P, Cerdà A, Úbeda X, Mataix-Solera J, Arcenegui V, Zavala LM (2015) Modelling the impacts of wildfire on ash thickness in a short-term period. Land Degradation and Development 26, 180–192.
Modelling the impacts of wildfire on ash thickness in a short-term period.Crossref | GoogleScholarGoogle Scholar |

Pereira P, Cerdà A, Úbeda X, Mataix-Solera J, Martin D, Jordán A, Burguet M (2013b) Spatial models for monitoring the spatiotemporal evolution of ashes after fire – a case study of a burnt grassland in Lithuania. Solid Earth 4, 153–165.
Spatial models for monitoring the spatiotemporal evolution of ashes after fire – a case study of a burnt grassland in Lithuania.Crossref | GoogleScholarGoogle Scholar |

Platzer C, Mauch K (1997) Soil clogging in vertical flow reed beds – mechanisms, parameters, consequences and... solutions? Water Science and Technology 35, 175–181.
Soil clogging in vertical flow reed beds – mechanisms, parameters, consequences and... solutions?Crossref | GoogleScholarGoogle Scholar |

R Development Core Team (2010) R: A language and environment for statistical computing. (R Foundation for Statistical Computing: Vienna, Austria) Available at www.R-project.org [Verified 3 November 2015]

Rawls WJ, Brakensiek DL, Saxtonn KE (1982) Estimation of soil water properties. Transactions of the ASAE 25, 1316–1320.
Estimation of soil water properties.Crossref | GoogleScholarGoogle Scholar |

Ritsema CJ, Dekker LW (1995) Distribution flow: a general process in the top layer of water-repellent soils. Water Resources Research 31, 1187–1200.
Distribution flow: a general process in the top layer of water-repellent soils.Crossref | GoogleScholarGoogle Scholar |

Ross B (1990) The diversion capacity of capillary barriers. Water Resources Research 26, 2625–2629.
The diversion capacity of capillary barriers.Crossref | GoogleScholarGoogle Scholar |

Rubio CM (2014) Short-term change in the thermal conductivity of a loam soil after forest fire. European Journal of Environmental and Safety Sciences 2, 28–36. . Available at http://www.sci-institute.com/2014_volume_2_issue_2/rubio.pdf [Verified 27 October 2015]

Saiers JE, Hornberger GM, Gower DB, Herman JS (2003) The role of moving air–water interfaces in colloid mobilization within the vadose zone. Geophysical Research Letters 30, 2083
The role of moving air–water interfaces in colloid mobilization within the vadose zone.Crossref | GoogleScholarGoogle Scholar |

Sang W, Morales VL, Zhang W, Stoof CR, Gao B, Schatz AL, Zhang Y, Steenhuis TS (2013) Quantification of colloid retention and release by straining and energy minima in variably saturated porous media. Environmental Science & Technology 47, 8256–8264.

Sang W, Stoof CR, Zhang W, Morales VL, Gao B, Kay RW, Liu L, Zhang Y, Steenhuis TS (2014) Effect of hydrofracking fluid on colloid transport in the unsaturated zone. Environmental Science & Technology 48, 8266–8274.
Effect of hydrofracking fluid on colloid transport in the unsaturated zone.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXptl2itLk%3D&md5=e2f3ac1a95ef8637018ac0bdfe73c5a3CAS |

Santín C, Doerr SH, Shakesby RA, Bryant R, Sheridan GJ, Lane PN, Smith HG, Bell TL (2012) Carbon loads, forms and sequestration potential within ash deposits produced by wildfire: new insights from the 2009 ‘Black Saturday’ fires, Australia. European Journal of Forest Research 131, 1245–1253.
Carbon loads, forms and sequestration potential within ash deposits produced by wildfire: new insights from the 2009 ‘Black Saturday’ fires, Australia.Crossref | GoogleScholarGoogle Scholar |

Schroth MH, Istok JD, Selker JS (1998) Three-phase immiscible fluid movement in the vicinity of textural interfaces. Journal of Contaminant Hydrology 32, 1–23.
Three-phase immiscible fluid movement in the vicinity of textural interfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXktFOmsrw%3D&md5=0c6b85d22dd3a54700a916096dacb0a2CAS |

Scott DF (1997) The contrasting effects of wildfire and clearfelling on the hydrology of a small catchment. Hydrological Processes 11, 543–555.
The contrasting effects of wildfire and clearfelling on the hydrology of a small catchment.Crossref | GoogleScholarGoogle Scholar |

Shakesby RA, Doerr SH (2006) Wildfire as a hydrological and geomorphological agent. Earth-Science Reviews 74, 269–307.
Wildfire as a hydrological and geomorphological agent.Crossref | GoogleScholarGoogle Scholar |

Smesrud JK, Selker JS (2001) Effect of soil-particle size contrast on capillary barrier performance. Journal of Geotechnical and Geoenvironmental Engineering 127, 885–888.
Effect of soil-particle size contrast on capillary barrier performance.Crossref | GoogleScholarGoogle Scholar |

Smith HG, Sheridan GJ, Lane PNJ, Nyman P, Haydon S (2011) Wildfire effects on water quality in forest catchments: a review with implications for water supply. Journal of Hydrology 396, 170–192.
Wildfire effects on water quality in forest catchments: a review with implications for water supply.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsF2htbnK&md5=e4bf7eee756ff5fda0b433a46018c986CAS |

Soil Survey Division Staff (1993) ‘Soil survey manual’, Handbook 18. (United States Department of Agriculture: Washington, DC) Available at http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_054262 [Verified 17 November 2015]

Steenhuis TS, Parlange JY, Kung KJS (1991) Comment on ‘The diversion capacity of capillary barriers’ by Benjamin Ross. Water Resources Research 27, 2155–2156.
Comment on ‘The diversion capacity of capillary barriers’ by Benjamin Ross.Crossref | GoogleScholarGoogle Scholar |

Steinberg PD (2002) Pseudotsuga menziesii var. glauca. In ‘Fire Effects Information System’ [online database]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Available at http://feis-crs.org/beta/ [Verified 3 November 2015]

Stolte J (1997) Determination of the saturated hydraulic conductivity using the constant head method. In ‘Manual for soil physical measurements, version 3, Technical Document 37’. (Ed. J Stolte) pp. 27–32. (DLO – Staring Centre: Wageningen, The Netherlands)

Stoof CR, Wesseling JG, Ritsema CJ (2010) Effects of fire and ash on soil water retention. Geoderma 159, 276–285.
Effects of fire and ash on soil water retention.Crossref | GoogleScholarGoogle Scholar |

Stoof CR, Moore D, Ritsema CJ, Dekker LW (2011) Natural and fire-induced soil water repellency in a Portuguese shrubland. Soil Science Society of America Journal 75, 2283–2295.
Natural and fire-induced soil water repellency in a Portuguese shrubland.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsVKjs7jF&md5=5b1f8f27acbd93a1c9cc94bef7589671CAS |

Stoof CR, Vervoort RW, Iwema J, van den Elsen E, Ferreira AJD, Ritsema CJ (2012) Hydrological response of a small catchment burned by experimental fire. Hydrology and Earth System Sciences 16, 267–285.
Hydrological response of a small catchment burned by experimental fire.Crossref | GoogleScholarGoogle Scholar |

Stoof CR, Slingerland EC, Mol W, van den Berg J, Vermeulen PJ, Ferreira AJD, Ritsema CJ, Parlange JY, Steenhuis TS (2014) Preferential flow as a potential mechanism for fire-induced increase in streamflow. Water Resources Research 50, 1840–1845.
Preferential flow as a potential mechanism for fire-induced increase in streamflow.Crossref | GoogleScholarGoogle Scholar |

Tan S-A, Fwa T-F, Han C-T (2003) Clogging evaluation of permeable bases. Journal of Transportation Engineering 129, 309–315.
Clogging evaluation of permeable bases.Crossref | GoogleScholarGoogle Scholar |

Taubaso C, Dos Santos Afonso M, Torres Sánchez RM (2004) Modelling soil surface charge density using mineral composition. Geoderma 121, 123–133.
Modelling soil surface charge density using mineral composition.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXkvF2hsb8%3D&md5=c3b26134acb3b8af6e1e53931d03ea2bCAS |

Vervoort R, Cattle S (2003) Linking hydraulic conductivity and tortuosity parameters to pore space geometry and pore-size distribution. Journal of Hydrology 272, 36–49.
Linking hydraulic conductivity and tortuosity parameters to pore space geometry and pore-size distribution.Crossref | GoogleScholarGoogle Scholar |

Wang D, Zhang W, Zhou D (2013) Antagonistic effects of humic acid and iron oxyhydroxide grain-coating on biochar nanoparticle transport in saturated sand. Environmental Science & Technology 47, 5154–5161.
Antagonistic effects of humic acid and iron oxyhydroxide grain-coating on biochar nanoparticle transport in saturated sand.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXmsVCgu7c%3D&md5=bb2cb4dc7d30c469d0506e9afbc1fa41CAS |

Wang Z, Wu L, Wu Q (2000) Water-entry value as an alternative indicator of soil water-repellency and wettability. Journal of Hydrology 231–232, 76–83.
Water-entry value as an alternative indicator of soil water-repellency and wettability.Crossref | GoogleScholarGoogle Scholar |

Woods SW, Balfour VN (2008) The effect of ash on runoff and erosion after a severe forest wildfire, Montana, USA. International Journal of Wildland Fire 17, 535–548.
The effect of ash on runoff and erosion after a severe forest wildfire, Montana, USA.Crossref | GoogleScholarGoogle Scholar |

Woods SW, Balfour VN (2010) The effects of soil texture and ash thickness on the post-fire hydrological response from ash-covered soils. Journal of Hydrology 393, 274–286.
The effects of soil texture and ash thickness on the post-fire hydrological response from ash-covered soils.Crossref | GoogleScholarGoogle Scholar |

Wu F-C, Huang H-T (2000) Hydraulic resistance induced by deposition of sediment in porous medium. Journal of Hydraulic Engineering 126, 547–551.
Hydraulic resistance induced by deposition of sediment in porous medium.Crossref | GoogleScholarGoogle Scholar |

Zevi Y, Dathe A, Gao B, Richards BK, Steenhuis TS (2006) Quantifying colloid retention in partially saturated porous media. Water Resources Research 42, W12S03
Quantifying colloid retention in partially saturated porous media.Crossref | GoogleScholarGoogle Scholar |

Zhang W, Morales VL, Cakmak ME, Salvucci AE, Geohring LD, Hay AG, Parlange J-Y, Steenhuis TS (2010a) Colloid transport and retention in unsaturated porous media: effect of colloid input concentration. Environmental Science & Technology 44, 4965–4972.
Colloid transport and retention in unsaturated porous media: effect of colloid input concentration.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXmvFKmtbY%3D&md5=dc684b2e7ea4b544669adcdfe5542240CAS |

Zhang W, Niu J, Morales VL, Chen X, Hay AG, Lehmann J, Steenhuis TS (2010b) Transport and retention of biochar particles in porous media: effect of pH, ionic strength, and particle size. Ecohydrology 3, 497–508.
Transport and retention of biochar particles in porous media: effect of pH, ionic strength, and particle size.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXis1antA%3D%3D&md5=a33d9d1cceb6f9cb9a05daac5b16e8f2CAS |

Zhuang J, Goeppert N, Tu C, McCarthy J, Perfect E, McKay L (2010) Colloid transport with wetting fronts: interactive effects of solution surface tension and ionic strength. Water Research 44, 1270–1278.
Colloid transport with wetting fronts: interactive effects of solution surface tension and ionic strength.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXitFyks74%3D&md5=a44a730a52797834b4e4c96754747416CAS | 20056511PubMed |