Spatial Distribution of Drifted-wood Hazard following the July 2017 Sediment-hazards in the Akatani river, Fukuoka Prefecture, Japan

Mariko Shimizu(1), Sayaka Kanai(2), Norifumi Hotta(3), Candide Lissak(4), Christopher Gomez(5*)

(1) Kobe University, Graduate School of Maritime Sciences, Laboratory of Sediment Hazards and Disaster Risk
(2) Kobe University, Graduate School of Maritime Sciences, Laboratory of Sediment Hazards and Disaster Risk
(3) Graduate School of Agricultural and Life Sciences, The University of Tokyo
(4) Caen University, Dept. of Geography, Laboratory Geophen, France
(5) Kobe University, Graduate School of Maritime Sciences, Higashinada-ku, Fukae-Minamimachi 5-1-1, 658-0022 Kobe City, Japan
(*) Corresponding Author


In recent years, heavy rainfall leading to floods, landslides and debris-flow hazards have had increasing impacts on communities in Japan, because of climate change and structural immobilism in a changing and ageing society. Decreasing rural population lowers the human vulnerability in mountains, but hazards can still leave the mountain to the plains and sea, potentially carrying drifted-wood. The aim of the paper is to measure the distribution of wood-debris deposits created by the 2017 Asakura disaster and to rethink the distribution and spatial extension of associated disaster-risk zoning. For this purpose, the authors: (1) digitized and measured the distribution of drifted-wood, (2) statistically analyzed its distribution and (3) calculated the potential impact force of individual drifted timber as a minimal value. The results have shown that there is a shortening of the wood debris as they travel downstream and that the geomorphology has an important control over deposition zones. The result of momentum calculation for different stems’ length show spatially differentiated hazard-zones, which limit different disaster-risk potentials. From the present finding, we can state that we (1) need to develop separate strategies for sediments and wood debris (2) and for wood hazards, zonations can be generated depending on the location and the size of the deposited trees that differs spatially in a watershed.


drifted woods, heavy rainfall, landslide, debris flow, hazards.

Full Text:



Benda, L.E., Sias, J.C. (2003) A quantitative framework for evaluating the mass balance in-stream organic debris. Forest Ecology and Management Vol. 172, p. 1-16.

Benke, A.C., Wallace, B.J. (2003) Influence of wood on invertebrate communitites in streams and rivers. In Gregory, Boyer and Gurnell (Eds.). The ecology and management of wood in world rivers symposium proceedings, p. 149-177.

Blong, R. (1981) Some effects of tephra falls on buildings. S. Self, R.S.J. Sparks (Eds.). Tephra Studies. p. 405-420.

Chaithong, T., Komori, D., Sukegawa, Y., Anzai, S. (2018) Estimating woody debris recruitment in a stream caused by a typhoon-induced landslide: a case study of typhoon Lionrock in Iwaizumi, Iwate Prefecture, Japan. Geomatics, Natural Hazards and Risks vol. 9, p. 1071-1084.

Chen, J., Wang, D., Zhao, W., Chen, H., Wang, T., Nepal, N., Chen, X. (2020) Laboratory study on the characteristics of large wood and debris flow processes at slit-check dams. Landslides vol. 17, p. 1703-1711.

Comiti, F. (2012) How natural are alpine mountain rivers? Evidence from the Italian Alps. Earth Surface Proceses and Landforms vol. 37, p. 693-707.

Comiti, F., Agostino, V.D., Moser, M., Lenzi, M.A., Bettella, F., Agnese, A.D., Rigon, E., Gius, S., Mazzorana, B. (2012) Preventing wood-related hazards in mountain basins: from wood load estimation to designing retention structures. 12th INTERPRAEVENT congress 2012 – Grenoble, France, Conference proceedings p. 651-662.

Conley, W., Kramer, N. (2020) Riverine large wood and recreation safety: A framework to discretize and contextualize hazard. Earth Surface Processes and Landforms vol. 45, p. 2201-2216.

Cullen, A., Frei, H. (1999) Probabilistic Techniques in Exposure Assessment: Plenum Publishing.

Delignette-Muller, M.L., Dutang, C. (2020) Fitdistrplus: An R Package for Fitting Distributions. Available online: [1st October 2020]

Diehl, T.H. (1997) Potential drift accumulation at bridges. Report FHWA-RD-97028 of the US Department of Transportation, Federal highway Administration.

Efron, B. (1979) Bootstrap methods: another look at the jackknife. Annals of Statistics vol. 7, p. 1-26.

Efron, B. (1981) Nonparametric estimates of standard error: the jackknife, the bootstrap, and other methods. Biometrika vol. 65, p. 589-599.

Gomez, C. (2018) The Asakura Sediment and Tree Disaster: Drifted Wood Distribution and Flow Dynamics from UAV and Aircraft Remote Sensing. Seminar at the Ministry of Land, Infrastructure and Transport, SABO division, Tsukuba University (June 2018).

Gurnell, A. (2013) Wood in fluvial systems, Treatise on Geomorphology vol. 9, p. 163-188.

Iroume, A., Cartagena, M., Villablanca, L., Sanhueza, D., Mazzorana, B. Picco, L. (2020) Long-term large wood load fluctuations in two low-order streams in Southern Chile. Earth Surface Processes and Landforms vol.45, Issue 9, p. 1959-1973.

Kimura, N., Tai, A., Hashimoto, A. (2017) Flood caused by driftwood accumulation at a bridge. International Journal of Disaster Resilience in the Built Environment vol. 8. p.466-477.

Komatsu, M., Uchida, T., Sakurai, W. (2019) An analysis for premonitory phenomena from recent sediment-related disasters. Journal of the Japan Society of Erosion Control Engineering vol.72, No.1 p.37-44

Le Lay, Y.F., Piegay, H., Moulin, B. (2013) Wood entrance, deposition, transfer and effects on fluvial forms and processes: problem statements and challenging issues, Treatise of Geomorphology vol. 12, p. 20-36.

Li, M., Hasemi, Y., Nozoe, Y. (2019) Study on disaster risks and countermeasures influenced by the impact of the modernization process in historical mountain villages: A case study of Hanazawa historical village, Japan. International Journal of Disaster Risk Reduction vol. 41, p. 1-14.

Lucia, A., Schwientek, M., Eberle, J., Zarfl, C. (2018) Planform changes and large wood dynamics in two torrents during a severe flash flood in Braunsbach, Germany 2016. Science of the Total Environment vol. 640-641, p. 315-326.

Lyn, D., Cooper, T., Condon, D., Gan, L. (2007) Factors in debris accumulation at bridge piers. Department of Transportation, Federal Highway Administration Research and Development, Turner-Fairbank Highway Research Centre, Washington.

Nakatani, K., Kosugi, M., Satofuka, Y., Mizuyama, T. (2016) Debris-flow Flooding and Debris Deposition Considering the Effect of Houses: Disaster Verification and Numerical Simulation. International Journal of Erosion Control Engineering vol. 9, p. 145-154.

Sahara, K., Ikeda, T., Iwai, Y., Kakuta, K., Kanazawa, A., Gonda, Y., Saitou, Y., Shuin, Y., Tagata, S., Fujita, M., Miyata, S., Miwa, H. (2019) Sediment disasters in Shikoku region in July, 2018.Journal of the Japan Society of Erosion Control Engineering vol.71, No.5, p. 43-53

Sato, H., Nagasawa, Y., Asai, T., Terazawa, K. (2006) Quantification of the woody debris in Appetsu river basin by Typhoon 0310, Etsu. Journal of the Japan Society of Erosion Control Engineering, vol.58, No.6, p.11-17

Shimizu, O., Kodama, R., Kasai, M. (2018) Proposal of a new idea for designating hazard areas based on travel distance of sediment and woody debris discharged from rainfall-induced landslides in Aso caldera walls. Journal of the Japan Society of Erosion Control Engineering, vol.70, No.5, p.3-14

Steeb, N., Rickenmann, D., Badoux, A., Rickli, C., Waldner, P. (2017) Large wood recruitment processes and transported volumes in Swiss mountain streams during the extreme flood of august 2005. Geomorphology vol. 279, p. 112-127.

Tanaka, T., Tsuchiya, S., Yukawa, N., Furuta, K., Nakazawa, K. (2019) Landslides and sediment runoff caused by the long-duration rain of July 2018 in Gujo-shi, Gifu prefecture. Journal of the Japan Society of Erosion Control Engineering vol.71, No.5, p38-42

Wohl, E., Cenderelli, D.A., Dwire, K.A., Ryan-Burkett, S.E., Young, M.K., Fausch, K.D. (2010) Large in-stream wood studies: A call for common metrics. Earth Surface Processes and Landforms vol. 35, p. 618-625.

Yamada, K., Nagasaka, Y., Tsushima, T., Abe, T. (2006) Quantitative study of the area of damage and the amount of lost or trapped timber in a riparian forest in the Appetsu River basin caused by Typhoon 0310 (Etau). Journal of the Japan Society of Erosion Control Engineering vol.59, No.1, p.13-20

Article Metrics

Abstract view(s): 638 time(s)
HTML: 386 time(s) PDF: 315 time(s)


  • There are currently no refbacks.