Precipitation patterns control the distribution and export of large wood at the catchment scale
Large wood (LW) plays an important role in river ecosystems, but LW‐laden floods may cause serious damage to human lives and property. The relationship between precipitation patterns and variations in LW distribution and export at the watershed scale is poorly understood. To explore these linkages,...
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Published in | Hydrological processes Vol. 29; no. 24; pp. 5044 - 5057 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester
Wiley
29.11.2015
Blackwell Publishing Ltd Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Large wood (LW) plays an important role in river ecosystems, but LW‐laden floods may cause serious damage to human lives and property. The relationship between precipitation patterns and variations in LW distribution and export at the watershed scale is poorly understood. To explore these linkages, we examined differences in LW distribution as a function of channel morphologies in six watersheds located in southern and northern Japan and analysed the impacts of different precipitation patterns on the fluvial export of LW from river catchments. In southern Japan, intense rainfalls caused by typhoons or localized torrential downpours initiate landslides and debris flows that introduce massive amounts of LW into channels. Gravel bars formed by frequent flood events are widely prevalent, and the LW temporarily stored on these bars is frequently moved and/or broken into smaller pieces by floods. In these systems fluvial export of LW is supply‐limited, with smaller accumulations and shorter residence times than in northern Japan. Conversely, in northern Japan, where typhoons and torrential downpours rarely occur, LW is mostly recruited by bank erosion, tree mortality and windthrow into channels, rather than by landslides and debris flows. Recruited pieces accumulate in log jams on valley floors, particularly on floodplains supporting mature forests, resulting in larger accumulations and longer residence times. In these watersheds fluvial export of LW is transport‐limited, and the pieces gradually decompose during long‐term storage as log jams. |
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Bibliography: | http://dx.doi.org/10.1002/hyp.10473 Supporting info item Water Resources Environment Technology Center and the Grants in Aid for Scientific Research - No. 23248021 Forest Science and Technology Projects - No. S111214L050110 ark:/67375/WNG-C3Q5XKGT-9 ArticleID:HYP10473 istex:2E882C0F513DA98F19B48641FB83DD1CC89CAEC9 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0885-6087 1099-1085 |
DOI: | 10.1002/hyp.10473 |