Spatio-temporal streamflow generation in a small,steep headwater catchment in western Japan |
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| Authors: | Haotian Sun Tamao Kasahara Kyoichi Otsuki Takami Saito Yuichi Onda |
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| Institution: | 1. Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan;2. Faculty of Agriculture, Kyushu University, Fukuoka, Japan;3. Kasuya Research Forest, Kyushu University, Fukuoka, Japan;4. Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan;5. Centre for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Ibaraki, Japan |
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| Abstract: | Headwaters contribute a substantial part of the flow in river networks. However, spatial variations of streamflow generation processes in steep headwaters have not been well studied. In this study, we examined the spatio-temporal variation of streamflow generation processes in a steep 2.98-ha headwater catchment. The time when baseflow of the upstream section exceeded that downstream was coincident with the time when the riparian groundwater switched from downwelling to upwelling. This suggests that upwelling of the riparian groundwater increased considerably in the upstream section during the wet period, producing a shift in the relative size of baseflow between the upstream and downstream sections. The timing of fluctuations among hillslope soil moisture, hillslope groundwater and streamflow reveals that the hillslope contributed to storm flow, but this contribution was limited to the wet period. Overall, these results suggest that streamflow generation has strong spatial variations, even in small, steep headwater catchments. EDITOR A. Castellarin ASSOCIATE EDITOR X. Chen |
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| Keywords: | Headwater water yield groundwater soil moisture spatio-temporal streamflow generation |
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