Tunnel development over a 12 year period in a semi‐arid catchment of the Loess Plateau, China

The tunnel systems in a semi-arid catchment of the Loess Plateau of China were repeatedly surveyed prior to the rainy seasons of 1989, 1999 and 2001. The surveys aimed to: (1) measure tunnel development over the 12 year period 1989–2001; (2) explore how the physiographical conditions affect the spatio-temporal variability of tunnel development; and (3) to identify the geomorphic processes associated with tunnel development. The ultimate goal was to quantify the geomorphic significance of tunnel systems in the catchment. Over the 12 year period, the number of tunnel inlets was more than doubled and most of the newly increased inlets were initiated in the few catastrophic storm events. However, tunnel enlargement can occur in storm or inter-storm periods, mainly through earth falls and slumps in inlets, and water erosion and roof cave-in collapses in tunnel paths. Tunnel development varied with material properties, land uses and topographic conditions. Net tunnel erosion may contribute at least 25–30% of the catchment sediment yield and was mainly produced by the initiation and enlargement of tunnel inlets rather than tunnel paths. To protect the areas against tunnel erosion, terracing of the upper slopes seems to be more effective than planting vegetation on the lower slopes. Copyright © 2003 John Wiley & Sons, Ltd.

[1]  J. A. Jones,et al.  Factors controlling the distribution of piping in Britain: a reconnaissance , 1997 .

[2]  Q. Cai,et al.  Tunnel erosion and sediment production in the hilly loess region, North China , 2002 .

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

[4]  R. Bryan,et al.  The significance of soil piping processes: inventory and prospect , 1997 .

[5]  R. Walsh,et al.  Soil pipes and their role in runoff generation and chemical denudation in a humid tropical catchment in dominica , 1988 .

[6]  W. W. Wood,et al.  Piping and pseudokarst in drylands , 1990 .

[7]  R. Crouch,et al.  Tunnel formation processes in the Riverina area of N.S.W., Australia , 1986 .

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

[9]  J. A. Jones.  The role of natural pipeflow in hillslope drainage and erosion: Extrapolating from the Maesnant data , 1997 .

[10]  Neil Owen Jones,et al.  The development of piping erosion , 1968 .

[11]  R. Bryan,et al.  Observations on the geomorphic significance of tunnel erosion in a semi-arid ephemeral drainage system , 1985 .

[12]  T. Lasanta,et al.  Soil erosion by piping in irrigated fields , 1997 .

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

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

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

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

[17]  J. A. Jones.  Pipeflow contributing areas and runoff response , 1997 .