Spatial pattern of infiltration rate and its effect on hydrological processes in a small headwater catchment

• DOI: 10.1002/hyp.7549
• Publication Date: 2010-01-14T09:11:05Z
• Authors: Shusuke Miyata; Ken'ichirou Kosugi; Yotaro Nishi; Takashi Gomi; Roy C. Sidle; Takahisa Mizuyama
• Keywords: Infiltration (HVAC); Subsurface Flow

Abstract Overland flow, which occurs when the rainfall intensity exceeds infiltration rate, is an important factor in hillslope hydrological processes. Recent studies have suggested that a cause of Hortonian overland flow on forested hillslopes water repellency surface soils. However, few addressed contribution storm runoff such catchments. The generated needs to reach stream channels order contribute from catchment. Therefore, spatial pattern rate essential for understanding runoff. To clarify hillslope, and its effect generation small catchment with repellent soil, we conducted artificial experiments along transect (49 m) 15 occasions over 20 months measured at plot (8 × m), outlet (0·43 ha), matric potential head transect. replicated measurements suggest relationship between soil moisture was positive due impact repellency, lower part significantly higher than upper middle parts. individual storms scale generally greater during dry periods wet periods, suggesting reduced as noted experiment scale. In contrast, stormflow all events showed opposite trend, indicating not sufficient or continuous enough measurable increases stormflow. For event < 100 mm total precipitation, comparison responses suggests subsurface rather contributed even though substantial amount plot. Copyright © 2010 John Wiley & Sons, Ltd.