The role of lateral pipe flow in hillslope runoff response: an intercomparison of non-linear hillslope response

The importance of lateral pipe flow on runoff generation in wet steep hillslopes has been described in many case studies from around the world. However, most hillslope studies are done in isolation and usually focus on the idiosyncrasies of individual hillslope characteristics and pipe flow response at a single site. Consequently, the first order controls on pipe flow responses remain poorly understood. We present a new intercomparison of pipe flow response to storm rainfall at four well instrumented sites: Panola (Georgia, USA), Toinotani (Kyoto, Japan), Jozankei (Hokkaido, Japan) and Hakyuchi (Tokyo, Japan). Our objective was to minimize the complexities of lateral pipe flow on hillslopes by looking for commonality across different hillslope types. Despite the large differences between the study sites in topography, climate, soil type and soil matrix hydraulic conductivity, we found several common pipe flow responses to storm rainfall: (1) the relationship between total rainfall amount and total pipe flow volume was highly non-linear at each site, (2) initiation of measurable pipe flow was threshold-dependent, controlled by the total rainfall amount and the pre-storm wetness, (3) once significant pipe flow response occurred, the maximum pipe flow rate was sensitive to the measured rainfall intensity, and (4) the ratio of total pipe flow to total hillslope discharge for each site was constant, regardless of total rainfall amount once the precipitation threshold for significant pipe flow response was reached. We used these results to develop a decision tree to determine the general conditions necessary for significant pipe flow to occur. The controls derived from our comparisons agree largely with the controls reported by the previous individual hillslope pipe flow studies in the literature. The commonality of response between our four very different forested hillslope settings indicates that site intercomparison may be effective for extracting common first order controls on complex hillslope processes. We argue that a decision tree may be a useful organizational framework to summarize and organize comparative analyses and may provide a structure for defining the hierarchy of process controls necessary for model development.

[1]  M. Newson,et al.  Soil pipes and pipeflow: A hydrological study in upland Wales , 1980 .

[2]  Keith Beven,et al.  NEW METHOD DEVELOPED FOR STUDYING FLOW ON HILLSLOPES , 1996 .

[3]  R. D. Black,et al.  An Experimental Investigation of Runoff Production in Permeable Soils , 1970 .

[4]  J. A. A. Jones,et al.  A semi-distributed simulation model for natural pipeflow , 2002 .

[5]  Helmut Elsenbeer,et al.  Hydrometric and hydrochemicai evidence for fast flowpaths at La Cuenca, Western Amazonia , 1996 .

[6]  Y. Onda,et al.  The role of subsurface runoff through bedrock on storm flow generation , 2001 .

[7]  Takahisa Mizuyama,et al.  Runoff characteristics of pipeflow and effects of pipeflow on rainfall-runoff phenomena in a mountainous watershed , 1999 .

[8]  D. Walling,et al.  Catchment Experiments in Fluvial Geomorphology , 1984 .

[9]  M. Mccaig.  Contributions to storm quickflow in a small headwater catchment—the role of natural pipes and soil macropores , 1983 .

[10]  Jeffrey J. McDonnell,et al.  Tracer and hydrometric study of preferential flow in large undisturbed soil cores from the Georgia Piedmont, USA , 1999 .

[11]  Hydrology of a forested hillslope during storm events , 1990 .

[12]  S. P. Anderson,et al.  Hydrologic response of a steep, unchanneled valley to natural and applied rainfall , 1997 .

[13]  A. Rodhe.  On the generation of stream runoff in till soils , 1989 .

[14]  K. Beven,et al.  Macropores and water flow in soils , 1982 .

[15]  M. Tani.  Runoff generation processes estimated from hydrological observations on a steep forested hillslope with a thin soil layer , 1997 .

[16]  Kevin Bishop,et al.  Groundwater dynamics along a hillslope: A test of the steady state hypothesis , 2003 .

[17]  Joseph Holden,et al.  Piping and pipeflow in a deep peat catchment , 2002 .

[18]  Tongxin Zhu.  Deep-seated., complex tunnel systems — a hydrological study in a semi-arid catchment, Loess Plateau, China , 1997 .

[19]  A. Plamondon,et al.  Snowmelt runoff pathways in a boreal forest hillslope, the role of pipe throughflow , 1987 .

[20]  M. Bonell.  Progress in the understanding of runoff generation dynamics in forests , 1993 .

[21]  K. Beven,et al.  TOPOGRAPHIC CONTROLS ON SUBSURFACE STORM FLOWAT THE HILLSLOPE SCALE FOR TWO HYDROLOGICALLY DISTINCT SMALL CATCHMENTS , 1997 .

[22]  J. A. Jones,et al.  The effects of soil piping on contributing areas and erosion patterns , 1987 .

[23]  Jeffrey J. McDonnell,et al.  A rationale for old water discharge through macropores in a steep, humid catchment. , 1990 .

[24]  H. Kitahara,et al.  Pipe flow significance on subsurface discharge from the valley head of a small watershed , 1996 .

[25]  Shoji Noguchi,et al.  Morphological Characteristics of Macropores and the Distribution of Preferential Flow Pathways in a Forested Slope Segment , 1999 .

[26]  J. Buttle,et al.  Runoff processes on a forested slope on the Canadian shield , 1999 .

[27]  J. McDonnell,et al.  Base cation concentrations in subsurface flow from a forested hillslope: The role of flushing frequency , 1998 .

[28]  Felix Naef,et al.  A decision scheme to indicate dominant hydrological flow processes on temperate grassland , 2003 .

[29]  Glenn V. Wilson,et al.  Physical and chemical controls of preferred path flow through a forested hillslope , 1990 .

[30]  R. Z. Whipkey.  SUBSURFACE STORMFLOW FROM FORESTED SLOPES , 1965 .

[31]  Keith Beven,et al.  Hydrological processes—Letters. Topographic controls on subsurface storm flow at the hillslope scale for two hydrologically distinct small catchmetns , 1997 .

[32]  T. Mizuyama,et al.  Effects of pipe flow and bedrock groundwater on runoff generation in a steep headwater catchment in Ashiu, central Japan , 2002 .

[33]  Ratio of pipe flow to throughflow discharge , 1994 .

[34]  M. Bonell,et al.  SELECTED CHALLENGES IN RUNOFF GENERATION RESEARCH IN FORESTS FROM THE HILLSLOPE TO HEADWATER DRAINAGE BASIN SCALE 1 , 1998 .

[35]  Ming-ko Woo,et al.  The role of soil pipes as a slope runoff mechanism, Subarctic Yukon, Canada , 2000 .

[36]  G. G. Parker,et al.  The Nature of Soil Piping—A Review of Research , 1985 .

[37]  Shoji Noguchi,et al.  Stormflow generation in steep forested headwaters: a linked hydrogeomorphic paradigm , 2000 .

[38]  John F. Dowd,et al.  A new interpretation of kinematic stormflow generation , 2002 .

[39]  M. Bonell,et al.  The influence of scale of measurement on the spatial and temporal variability of the Philip infiltration parameters — An experimental study in an an Australian savannah woodland , 1988 .

[40]  Tomomi Terajima,et al.  Morphology, structure and flow phases in soil pipes developing in forested hillslopes underlain by a Quaternary sand–gravel formation, Hokkaido, northern main island in Japan , 2000 .

[41]  Yoshinori Tsukamoto,et al.  Runoff process on a steep forested slope , 1988 .

[42]  J. Kirchner.  A double paradox in catchment hydrology and geochemistry , 2003 .

[43]  Takahisa Mizuyama,et al.  Effects of pipeflow on hydrological process and its relation to landslide: a review of pipeflow studies in forested headwater catchments , 2001 .

[44]  P. Smart,et al.  Pipes and pipe flow process in an upland catchment, Wales , 1984 .

[45]  Ross Woods,et al.  The changing spatial variability of subsurface flow across a hillside , 1996 .

[46]  F. Swanson,et al.  Hydrologic inferences from comparisons among small basin experiments , 2001 .

[47]  R. Ziemer,et al.  Subsurface pipeflow dynamics of north-coastal California swale systems , 1987 .

[48]  M. Sivapalan.  Process complexity at hillslope scale, process simplicity at the watershed scale: is there a connection? , 2003 .

[49]  Keith Beven,et al.  Isotope studies of pipeflow at Plynlimon, Wales, UK. , 1996 .

[50]  T. Mizuyama,et al.  Seepage area and rate of bedrock groundwater discharge at a granitic unchanneled hillslope , 2003 .

[51]  Keith Beven,et al.  The role of bedrock topography on subsurface storm flow , 2002 .

[52]  M. Mosley.  Streamflow generation in a forested watershed, New Zealand , 1979 .

[53]  R. Moore,et al.  Throughflow variability on a forested hillslope underlain by compacted glacial till , 2000 .

[54]  J. McDonnell,et al.  Role of upslope soil pore pressure on lateral subsurface storm flow dynamics , 2004 .