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Effect of air mobility in a soil pipe on water flow through a model hillslope after pipe clogging
Author(s) -
Yamasaki Takuhei,
Hamamoto Shoichiro,
Nishimura Taku
Publication year - 2020
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.4782
Subject(s) - clogging , water table , drainage , pore water pressure , environmental science , geotechnical engineering , macropore , hydrology (agriculture) , water flow , geology , subsurface flow , flow (mathematics) , groundwater , mesoporous material , ecology , biochemistry , chemistry , archaeology , biology , history , catalysis , geometry , mathematics
Soil pipes (continuous macropores expanding laterally in the soil subsurface) are a key factor controlling hillslope water cycles and sediment transport. Soil pipes usually enhance slope stability under rainfall events through their high water drainage ability, and pipe clogging by sediments is regarded as a risk for slope failure. In this study, we conducted a bench‐scale pipe clogging experiment to clarify the effect of air mobility in soil pipes on water flow and water pressure build‐up in the slope at the clogged point. Before pipe clogging, the soil pipe drained rainwater effectively and lowered the groundwater table. After the pipe clogging event, the mobility of air in the soil pipe before the clogging determined the water flow in the slope. When the air in the soil pipe connected to the atmosphere and moved freely, the water level in the soil pipe increased at the pipe clogging, and water pressure build‐up was limited near the pipe outlet. On the other hand, when air in the soil pipe was entrapped by the clogging, water pressure suddenly increased, and the groundwater table of the whole slope rose correspondingly. This study clearly demonstrated the importance of pipe morphology with respect to air connectivity between the pipe and atmosphere to elucidate the water flow and slope stability during the pipe clogging event. © 2019 John Wiley & Sons, Ltd.