Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire
RESEARCH ARTICLE

Structural and functional connectivity as a driver of hillslope erosion following disturbance

C. Jason Williams A B F , Frederick B. Pierson A , Peter R. Robichaud C , Osama Z. Al-Hamdan A D , Jan Boll B D and Eva K. Strand E
+ Author Affiliations
- Author Affiliations

A Northwest Watershed Research Center, Agricultural Research Service, USDA, 800 Park Boulevard, Plaza 4, Suite 105, Boise, ID 83712, USA.

B Environmental Science and Water Resources, University of Idaho, 875 Perimeter Drive, MS 1142, Moscow, ID 83844-1142, USA.

C Rocky Mountain Research Station, Forest Service, USDA, 1221 South Main Street, Moscow, ID 83843, USA.

D Department of Biological and Agricultural Engineering, University of Idaho, 875 Perimeter Drive, MS 0904, Moscow, ID 83844-0904, USA.

E Department of Forest, Rangeland, and Fire Sciences, University of Idaho, 875 Perimeter Drive, MS 1133, Moscow, ID 83844-1133, USA.

F Corresponding author: Email: jason.williams@ars.usda.gov

International Journal of Wildland Fire 25(3) 306-321 https://doi.org/10.1071/WF14114
Submitted: 26 June 2014  Accepted: 9 April 2015   Published: 7 July 2015

Abstract

Hydrologic response to rainfall on fragmented or burnt hillslopes is strongly influenced by the ensuing connectivity of runoff and erosion processes. Yet cross-scale process connectivity is seldom evaluated in field studies owing to scale limitations in experimental design. This study quantified surface susceptibility and hydrologic response across point to hillslope scales at two degraded unburnt and burnt woodland sites using rainfall simulation and hydrologic modelling. High runoff (31–47 mm) and erosion (154–1893 g m–2) measured at the patch scale (13 m2) were associated with accumulation of fine-scale (0.5-m2) splash-sheet runoff and sediment and concentrated flow formation through contiguous bare zones (64–85% bare ground). Burning increased the continuity of runoff and sediment availability and yield. Cumulative runoff was consistent across plot scales whereas erosion increased with increasing plot area due to enhanced sediment detachment and transport. Modelled hillslope-scale runoff and erosion reflected measured patch-scale trends and the connectivity of processes and sediment availability. The cross-scale experiments and model predictions indicate the magnitude of hillslope response is governed by rainfall input and connectivity of surface susceptibility, sediment availability, and runoff and erosion processes. The results demonstrate the importance in considering cross-scale structural and functional connectivity when forecasting hydrologic and erosion responses to disturbances.

Additional keywords: ecohydrology, fire effects, infiltration, risk assessment, runoff, soil erosion, vegetation transition, wildfire, woodland encroachment.


References

Abrahams AD, Parsons AJ, Wainwright J (1995) Effects of vegetation change on interrill runoff and erosion, Walnut Gulch, southern Arizona. Geomorphology 13, 37–48.
Effects of vegetation change on interrill runoff and erosion, Walnut Gulch, southern Arizona.Crossref | GoogleScholarGoogle Scholar |

Al-Hamdan OZ, Pierson FB, Nearing MA, Williams CJ, Stone JJ, Kormos PR, Boll J, Weltz MA (2012a) Concentrated-flow erodibility for physically based erosion models: temporal variability in disturbed and undisturbed rangelands. Water Resources Research 48, W07504
Concentrated-flow erodibility for physically based erosion models: temporal variability in disturbed and undisturbed rangelands.Crossref | GoogleScholarGoogle Scholar |

Al-Hamdan OZ, Pierson FB, Nearing MA, Stone JJ, Williams CJ, Moffet CA, Kormos PR, Boll J, Weltz MA (2012b) Characteristics of concentrated-flow hydraulics for rangeland ecosystems: implications for hydrologic modeling. Earth Surface Processes and Landforms 37, 157–168.
Characteristics of concentrated-flow hydraulics for rangeland ecosystems: implications for hydrologic modeling.Crossref | GoogleScholarGoogle Scholar |

Al-Hamdan OZ, Pierson FB, Nearing MA, Williams CJ, Stone JJ, Kormos PR, Boll J, Weltz MA (2013) Risk assessment of erosion from concentrated flow on rangelands using overland flow distribution and shear stress partitioning. Transactions of the ASABE 56, 539–548.
Risk assessment of erosion from concentrated flow on rangelands using overland flow distribution and shear stress partitioning.Crossref | GoogleScholarGoogle Scholar |

Al-Hamdan OZ, Hernandez M, Pierson FB, Nearing MA, Williams CJ, Stone JJ, Boll J, Weltz MA (2015) Rangeland hydrology and erosion model (RHEM) enhancements for applications on disturbed rangelands. Hydrological Processes 29, 445–457.
Rangeland hydrology and erosion model (RHEM) enhancements for applications on disturbed rangelands.Crossref | GoogleScholarGoogle Scholar |

Benavides-Solorio JDD, MacDonald LH (2005) Measurement and prediction of post-fire erosion at the hillslope scale, Colorado Front Range. International Journal of Wildland Fire 14, 457–474.
Measurement and prediction of post-fire erosion at the hillslope scale, Colorado Front Range.Crossref | GoogleScholarGoogle Scholar |

Bisdom EBA, Dekker LW, Schoute JFT (1993) Water repellency of sieve fractions from sandy soils and relationships with organic material and soil structure. Geoderma 56, 105–118.
Water repellency of sieve fractions from sandy soils and relationships with organic material and soil structure.Crossref | GoogleScholarGoogle Scholar |

Bracken LJ, Croke J (2007) The concept of hydrological connectivity and its contribution to understanding runoff-dominated geomorphic systems. Hydrological Processes 21, 1749–1763.
The concept of hydrological connectivity and its contribution to understanding runoff-dominated geomorphic systems.Crossref | GoogleScholarGoogle Scholar |

Bracken LJ, Wainwright J, Ali GA, Tetzlaff D, Smith MW, Reaney SM, Roy AG (2013) Concepts of hydrological connectivity: research approaches, pathways and future agendas. Earth-Science Reviews 119, 17–34.
Concepts of hydrological connectivity: research approaches, pathways and future agendas.Crossref | GoogleScholarGoogle Scholar |

Cammeraat LH (2002) A review of two strongly contrasting geomorphological systems within the context of scale. Earth Surface Processes and Landforms 27, 1201–1222.
A review of two strongly contrasting geomorphological systems within the context of scale.Crossref | GoogleScholarGoogle Scholar |

Cannon SH, Powers PS, Savage WZ (1998) Fire-related hyperconcentrated and debris flows on Storm King Mountain, Glenwood Springs, Colorado, USA. Environmental Geology 35, 210–218.
Fire-related hyperconcentrated and debris flows on Storm King Mountain, Glenwood Springs, Colorado, USA.Crossref | GoogleScholarGoogle Scholar |

Cannon SH, Bigio ER, Mine E (2001a) A process for fire-related debris flow initiation, Cerro Grande fire, New Mexico. Hydrological Processes 15, 3011–3023.
A process for fire-related debris flow initiation, Cerro Grande fire, New Mexico.Crossref | GoogleScholarGoogle Scholar |

Cannon SH, Kirkham RM, Parise M (2001b) Wildfire-related debris-flow initiation processes, Storm King Mountain, Colorado. Geomorphology 39, 171–188.
Wildfire-related debris-flow initiation processes, Storm King Mountain, Colorado.Crossref | GoogleScholarGoogle Scholar |

Cannon SH, Gartner JE, Wilson RC, Bowers JC, Laber JL (2008) Storm rainfall conditions for floods and debris flows from recently burned areas in south-western Colorado and southern California. Geomorphology 96, 250–269.
Storm rainfall conditions for floods and debris flows from recently burned areas in south-western Colorado and southern California.Crossref | GoogleScholarGoogle Scholar |

Cannon SH, Boldt EM, Laber JL, Kean JW, Staley DM (2011) Rainfall intensity duration thresholds for post-fire debris-flow emergency-response planning. Natural Hazards 59, 209–236.
Rainfall intensity duration thresholds for post-fire debris-flow emergency-response planning.Crossref | GoogleScholarGoogle Scholar |

Cantón Y, Solé-Benet A, de Vente J, Boix-Fayos C, Calvo-Cases A, Asensio C, Puigdefábregas J (2011) A review of runoff generation and soil erosion across scales in semiarid south-eastern Spain. Journal of Arid Environments 75, 1254–1261.
A review of runoff generation and soil erosion across scales in semiarid south-eastern Spain.Crossref | GoogleScholarGoogle Scholar |

Davenport DW, Breshears DD, Wilcox BP, Allen CD (1998) Viewpoint: Sustainability of piñon–juniper ecosystems – a unifying perspective of soil erosion thresholds. Journal of Range Management 51, 231–240.
Viewpoint: Sustainability of piñon–juniper ecosystems – a unifying perspective of soil erosion thresholds.Crossref | GoogleScholarGoogle Scholar |

de Vente J, Poesen J (2005) Predicting soil erosion and sediment yield at the basin scale: scale issues and semi-quantitative models. Earth-Science Reviews 71, 95–125.
Predicting soil erosion and sediment yield at the basin scale: scale issues and semi-quantitative models.Crossref | GoogleScholarGoogle Scholar |

DeBano LF (1981) Water repellent soils: a state of the art. USDA Forest Service, Pacific Southwest Forest and Range Experiment Station, General Technical Report PSW-46. (Berkeley, CA)

Flanagan DC, Nearing MA (1995) USDA Water Erosion Prediction Project (WEPP) hillslope profile and watershed model documentation. USDA Agricultural Research Service, National Soil Erosion Research Laboratory, NSERL Report No. 10. (West Lafayette, IN)

Holland ME (1969) Colorado State University experimental rainfall-runoff facility, design and testing of a rainfall system. Colorado State University, Colorado State University Experimental Station, Report CER 69–70 MEH. (Fort Collins, CO)

Johansen MP, Hakonson TE, Breshears DD (2001) Post-fire runoff and erosion from rainfall simulation: contrasting forests with shrublands and grasslands. Hydrological Processes 15, 2953–2965.
Post-fire runoff and erosion from rainfall simulation: contrasting forests with shrublands and grasslands.Crossref | GoogleScholarGoogle Scholar |

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 |

Ludwig J, Tongway D, Freudenberger D, Noble J, Hodgkinson K (1997) ‘Landscape ecology: function and management – principles from Australia’s rangelands.’ (CSIRO: Melbourne)

Ludwig JA, Wilcox BP, Breshears DD, Tongway DJ, Imeson AC (2005) Vegetation patches and runoff-erosion as interacting ecohydrological processes in semiarid landscapes. Ecology 86, 288–297.
Vegetation patches and runoff-erosion as interacting ecohydrological processes in semiarid landscapes.Crossref | GoogleScholarGoogle Scholar |

Moody JA, Martin DA (2001a) 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, Martin DA (2001b) Post-fire, rainfall intensity–peak discharge relations for three mountainous watersheds in the western USA. Hydrological Processes 15, 2981–2993.
Post-fire, rainfall intensity–peak discharge relations for three mountainous watersheds in the western USA.Crossref | GoogleScholarGoogle Scholar |

Moody JA, Martin DA, Haire SL, Kinner DA (2008) Linking runoff response to burn severity after a wildfire. Hydrological Processes 22, 2063–2074.
Linking runoff response to burn severity after a wildfire.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 |

Natural Resources Conservation Service (NRCS) (2006) Soil Survey Geographic (SSURGO) database for Tooele Area, Utah – Tooele County and parts of Box Elder, Davis, and Juab Counties, Utah, White Pine and Elko Counties, Nevada. (USDA Natural Resources Conservation Service: Fort Worth, TX)

Natural Resources Conservation Service (NRCS) (2007) Soil Survey Geographic (SSURGO) database for Western White Pine County Area, Nevada, parts of White Pine and Eureka Counties. (USDA Natural Resources Conservation Service: Fort Worth, TX)

Nearing MA, Wei H, Stone JJ, Pierson FB, Spaeth KE, Weltz MA, Flanagan DC, Hernandez M (2011) A rangeland hydrology and erosion model. Transactions of the ASABE 54, 901–908.
A rangeland hydrology and erosion model.Crossref | GoogleScholarGoogle Scholar |

Neary DG, Koestner KA, Youberg A, Koestner PE (2012) Post-fire rill and gully formation, Schultz Fire 2010, Arizona, USA. Geoderma 191, 97–104.
Post-fire rill and gully formation, Schultz Fire 2010, Arizona, USA.Crossref | GoogleScholarGoogle Scholar |

Nyman P, Sheridan GJ, Moody JA, Smith HG, Noske PJ, Lane PNJ (2013) Sediment availability on burned hillslopes Journal of Geophysical Research: Earth Surface 118, 2451–2467.

Pannkuk CD, Robichaud PR (2003) Effectiveness of needle cast at reducing erosion after forest fires. Water Resources Research 39, 1333
Effectiveness of needle cast at reducing erosion after forest fires.Crossref | GoogleScholarGoogle Scholar |

Parsons A, Robichaud PR, Lewis SA, Napper C, Clark JT (2010) Field guide for mapping post-fire soil burn severity. USDA Forest Service, Rocky Mountain Research Station, General Technical Report, RMRS-GTR-243. (Fort Collins, CO)

Pierson FB, Jr, Van Vactor SS, Blackburn WH, Wood JC (1994) Incorporating small-scale spatial variability into predictions of hydrologic response on sagebrush rangelands. In ‘Variability in rangeland water erosion processes’, Soil Science Society of America Special Publication 38. pp. 23–24. (Soil Science Society of America: Madison, WI)

Pierson FB, Carlson DH, Spaeth KE (2002) Impacts of wildfire on soil hydrological properties of steep sagebrush–steppe rangeland. International Journal of Wildland Fire 11, 145–151.
Impacts of wildfire on soil hydrological properties of steep sagebrush–steppe rangeland.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Robichaud PR, Moffet CA, Spaeth KE, Hardegree SP, Clark PE, Williams CJ (2008a) Fire effects on rangeland hydrology and erosion in a steep sagebrush-dominated landscape. Hydrological Processes 22, 2916–2929.
Fire effects on rangeland hydrology and erosion in a steep sagebrush-dominated landscape.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Robichaud PR, Moffet CA, Spaeth KE, Williams CJ, Hardegree SP, Clark PE (2008b) Soil water repellency and infiltration in coarse-textured soils of burned and unburned sagebrush ecosystems. Catena 74, 98–108.
Soil water repellency and infiltration in coarse-textured soils of burned and unburned sagebrush ecosystems.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Moffet CA, Williams CJ, Hardegree SP, Clark PE (2009) Prescribed-fire effects on rill and interrill runoff and erosion in a mountainous sagebrush landscape. Earth Surface Processes and Landforms 34, 193–203.
Prescribed-fire effects on rill and interrill runoff and erosion in a mountainous sagebrush landscape.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Williams CJ, Kormos PR, Hardegree SP, Clark PE, Rau BM (2010) Hydrologic vulnerability of sagebrush steppe following pinyon and juniper encroachment. Rangeland Ecology and Management 63, 614–629.
Hydrologic vulnerability of sagebrush steppe following pinyon and juniper encroachment.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Williams CJ, Hardegree SP, Weltz MA, Stone JJ, Clark PE (2011) Fire, plant invasions, and erosion events on western rangelands. Rangeland Ecology and Management 64, 439–449.
Fire, plant invasions, and erosion events on western rangelands.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Williams CJ, Hardegree SP, Clark PE, Kormos PR, Al-Hamdan OZ (2013) Hydrologic and erosion responses of sagebrush steppe following juniper encroachment, wildfire, and tree cutting. Rangeland Ecology and Management 66, 274–289.
Hydrologic and erosion responses of sagebrush steppe following juniper encroachment, wildfire, and tree cutting.Crossref | GoogleScholarGoogle Scholar |

Pierson FB, Williams CJ, Kormos PR, Al-Hamdan OZ (2014) Short-term effects of tree removal on infiltration, runoff, and erosion in woodland-encroached sagebrush steppe Rangeland Ecology and Management 67, 522–538.
Short-term effects of tree removal on infiltration, runoff, and erosion in woodland-encroached sagebrush steppeCrossref | GoogleScholarGoogle Scholar |

Prism Group (2009) Prism Climate Group, Oregon State University. Available at: http://www.prism.oregonstate.edu/ [Verified 23 September 2009]

Puigdefábregas J (2005) The role of vegetation patterns in structuring runoff and sediment fluxes in drylands. Earth Surface Processes and Landforms 30, 133–147.
The role of vegetation patterns in structuring runoff and sediment fluxes in drylands.Crossref | GoogleScholarGoogle Scholar |

Puigdefábregas J, Sole A, Gutierrez L, Del Barrio G, Boer M (1999) Scales and processes of water and sediment redistribution in drylands: results from the Rambla Honda field site in south-east Spain. Earth-Science Reviews 48, 39–70.
Scales and processes of water and sediment redistribution in drylands: results from the Rambla Honda field site in south-east Spain.Crossref | GoogleScholarGoogle Scholar |

Reaney SM, Bracken LJ, Kirkby MJ (2007) Use of the Connectivity of Runoff Model (CRUM) to investigate the influence of storm characteristics on runoff generation and connectivity in semi-arid areas. Hydrological Processes 21, 894–906.
Use of the Connectivity of Runoff Model (CRUM) to investigate the influence of storm characteristics on runoff generation and connectivity in semi-arid areas.Crossref | GoogleScholarGoogle Scholar |

Reaney SM, Bracken LJ, Kirkby MJ (2014) The importance of surface controls on overland flow connectivity in semi-arid environments: results from a numerical experimental approach. Hydrological Processes 28, 2116–2128.
The importance of surface controls on overland flow connectivity in semi-arid environments: results from a numerical experimental approach.Crossref | GoogleScholarGoogle Scholar |

Robichaud PR, Elliot WJ, Pierson FB, Hall DE, Moffet CA (2007) Predicting post-fire erosion and mitigation effectiveness with a web-based probabilistic erosion model. Catena 71, 229–241.
Predicting post-fire erosion and mitigation effectiveness with a web-based probabilistic erosion model.Crossref | GoogleScholarGoogle Scholar |

Robichaud PR, Wagenbrenner JW, Brown RE, Wohlgemuth PM, Beyers JL (2008a) Evaluating the effectiveness of contour-felled log erosion barriers as a post-fire runoff and erosion mitigation treatment in the western United States. International Journal of Wildland Fire 17, 255–273.
Evaluating the effectiveness of contour-felled log erosion barriers as a post-fire runoff and erosion mitigation treatment in the western United States.Crossref | GoogleScholarGoogle Scholar |

Robichaud PR, Pierson FB, Brown RE, Wagenbrenner JW (2008b) Measuring effectiveness of three post-fire hillslope erosion barrier treatments, western Montana, USA. Hydrological Processes 22, 159–170.
Measuring effectiveness of three post-fire hillslope erosion barrier treatments, western Montana, USA.Crossref | GoogleScholarGoogle Scholar |

Robichaud PR, Lewis SA, Wagenbrenner JW, Ashmun LE, Brown RE (2013a) Post-fire mulching for runoff and erosion mitigation. Part I: Effectiveness at reducing hillslope runoff erosion rates. Catena 105, 75–92.
Post-fire mulching for runoff and erosion mitigation. Part I: Effectiveness at reducing hillslope runoff erosion rates.Crossref | GoogleScholarGoogle Scholar |

Robichaud PR, Wagenbrenner JW, Lewis SA, Ashmun LE, Brown RE, Wohlgemuth PM (2013b) Post-fire mulching for runoff and erosion mitigation. Part II: Effectiveness in reducing runoff and sediment yields from small catchments. Catena 105, 93–111.
Post-fire mulching for runoff and erosion mitigation. Part II: Effectiveness in reducing runoff and sediment yields from small catchments.Crossref | GoogleScholarGoogle Scholar |

SAS Institute (2008) ‘SAS System software, release 9.2.’ (SAS Institute Inc.: Cary, NC)

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 |

Shakesby RA, Doerr SH, Walsh RPD (2000) The erosional impact of soil hydrophobicity: current problems and future research directions. Journal of Hydrology 231–232, 178–191.
The erosional impact of soil hydrophobicity: current problems and future research directions.Crossref | GoogleScholarGoogle Scholar |

Smith RE, Goodrich DC, Woolhiser DA, Unkrich CL (1995) KINEROS: A kinematic runoff and erosion model. In ‘Computer models of watershed hydrology’. (Eds VJ Singh) Ch. 20, pp. 697–732. (Water Resources Publications: Highlands Ranch, CO)

Spigel KM, Robichaud PR (2007) First-year post-fire erosion rates in Bitterroot National Forest, Montana. Hydrological Processes 21, 998–1005.
First-year post-fire erosion rates in Bitterroot National Forest, Montana.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXlsVSqtLk%3D&md5=12bb45337336aade06f84a74e32e638cCAS |

Thornton PE, Thornton MM, Mayer BW, Wilhelmi N, Wei Y, Cook RB (2012) Daymet: daily surface weather on a 1-km grid for North America,1980–2011. Oak Ridge National Laboratory Distributed Active Archive Center. (Oak Ridge, TN) Available at http://daymet.ornl.gov/ [Verified 14 February 2013]10.3334/ORNLDAAC/DAYMET_V2

Turnbull L, Wainwright J, Brazier RE (2008) A conceptual framework for understanding semi-arid land degradation: ecohydrological interactions across multiple space and time scales. Ecohydrology 1, 23–34.
A conceptual framework for understanding semi-arid land degradation: ecohydrological interactions across multiple space and time scales.Crossref | GoogleScholarGoogle Scholar |

Turnbull L, Wainwright J, Brazier RE (2010a) Changes in hydrology and erosion over a transition from grassland to shrubland. Hydrological Processes 24, 393–414.

Turnbull L, Wainwright J, Brazier RE, Bol R (2010b) Biotic and abiotic changes in ecosystem structure over a shrub-encroachment gradient in the south-western USA. Ecosystems 13, 1239–1255.
Biotic and abiotic changes in ecosystem structure over a shrub-encroachment gradient in the south-western USA.Crossref | GoogleScholarGoogle Scholar |

Wagenbrenner JW, Robichaud PR (2013) Post-fire bedload sediment delivery across spatial scales in the interior western United States. Earth Surface Processes and Landforms
Post-fire bedload sediment delivery across spatial scales in the interior western United States.Crossref | GoogleScholarGoogle Scholar |

Wagenbrenner JW, MacDonald LH, Rough D (2006) Effectiveness of three post-fire rehabilitation treatments in the Colorado Front Range. Hydrological Processes 20, 2989–3006.
Effectiveness of three post-fire rehabilitation treatments in the Colorado Front Range.Crossref | GoogleScholarGoogle Scholar |

Wagenbrenner JW, Robichaud PR, Elliot WJ (2010) Rill erosion in natural and disturbed forests: 2. Modeling approaches. Water Resources Research 46, W10507
Rill erosion in natural and disturbed forests: 2. Modeling approaches.Crossref | GoogleScholarGoogle Scholar |

Wainwright J, Parsons AJ (2002) The effect of temporal variations in rainfall on scale dependency in runoff coefficients. Water Resources Research 38, 1271
The effect of temporal variations in rainfall on scale dependency in runoff coefficients.Crossref | GoogleScholarGoogle Scholar |

Wainwright J, Parsons AJ, Abrahams AD (2000) Plot-scale studies of vegetation, overland flow and erosion interactions: case studies from Arizona and New Mexico. Hydrological Processes 14, 2921–2943.
Plot-scale studies of vegetation, overland flow and erosion interactions: case studies from Arizona and New Mexico.Crossref | GoogleScholarGoogle Scholar |

Wei H, Nearing MA, Stone JJ, Guertin DP, Spaeth KE, Pierson FB, Nichols MH, Moffett CA (2009) A new splash and sheet erosion equation for rangelands. Soil Science Society of America Journal 73, 1386–1392.
A new splash and sheet erosion equation for rangelands.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXos1Ggtr4%3D&md5=0443ae01425ab9ec1276ab18ec86f57fCAS |

Western Regional Climate Center (WRCC) (2009) Western US climate historical summaries (individual stations). Available at http://www.wrcc.dri.edu/Climsum.html. [Verified 23 September 2009]

Wilcox BP, Pitlick J, Allen CD, Davenport DW (1996) Runoff and erosion from a rapidly eroding pinyon–juniper hillslope. In ‘Advances in hillslope processes.’ (Eds MG Anderson, SM Brooks.) Vol. 1, pp. 61–77. (Wiley: New York)

Wilcox BP, Breshears DD, Allen CD (2003) Ecohydrology of a resource-conserving semiarid woodland: effects of scale and disturbance. Ecological Monographs 73, 223–239.
Ecohydrology of a resource-conserving semiarid woodland: effects of scale and disturbance.Crossref | GoogleScholarGoogle Scholar |

Williams CJ, Pierson FB, Robichaud PR, Boll J (2014a) Hydrologic and erosion responses to wildfire along the rangeland–xeric forest continuum in the western US: a review and model of hydrologic vulnerability. International Journal of Wildland Fire 23, 155–172.
Hydrologic and erosion responses to wildfire along the rangeland–xeric forest continuum in the western US: a review and model of hydrologic vulnerability.Crossref | GoogleScholarGoogle Scholar |

Williams CJ, Pierson FB, Al-Hamdan OZ, Kormos PR, Hardegree SP, Clark PE (2014b) Can wildfire serve as an ecohydrologic threshold-reversal mechanism on juniper-encroached shrublands? Ecohydrology 7, 453–477.
Can wildfire serve as an ecohydrologic threshold-reversal mechanism on juniper-encroached shrublands?Crossref | GoogleScholarGoogle Scholar |