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CONSERVATION MEASURES OF CHANNEL STABILIZATION AND POOL-RIFFLE STRUCTURE RESTORATION IN THE HII RIVER

1 2 3 4 Tomoyuki NAGAI, Morihiro HARADA, Hironori HAYASHI and Kuniharu TAKAHASHI

1 812-0053 1 18 1

2 501-6021

3 819-0395 744 2 1008 4 812-0016 2-4-11

This paper reports a series of actions to conserve channel stabilization and pool-riffle structure in the Hii River disaster restoration works. The Hii River is an urban river which flow through Fukuoka city. First, the outline of heavy rainfall disaster in July 2009 is presented. Secondly, some concerning matters in the improvement plan are discussed. The largest issue was lack of channel stability after changing cross-sectional channel form by riverbed excavation. One dimensional bed deformation analyses were conducted to discuss channel stability and necessity of countermeasure. In result, the river administrator employed two new types of river structure to conserve channel stability and pool-riffle structure in the Hii River. This case study presents a way to resolve the conflict between disaster prevention and ecosystem conservation in urban rivers.

Key Words : pool-riffle structure, channel stabilization, movable bed simulation, rock riffle structure

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16 , pp.17-23, 2010. 2)

2013.( http://www.pref.fukuoka.lg.jp/gyosei-shiryo/houshin-dl.html) 3)

2010. 4)

B1( ), Vol.68, No.4, I_1291-I_1296, 2012.

5)

B1( ) Vol.70, No.4, I_997-I_1002, 2014. 6)

43-3, pp.148-159., 1970. 7)

17 , pp.113-118., 2011. 8)

, , 43(3), pp.289-296.,1995. 9)

pp.49-60, 2007. 10)

345 /II-1 pp.41-52., 1984.

11) - 12 p.4-5 2001.

12)

ELR2012, p.52, 2012.

13)

, Vol.19, pp.87-92, 2013. 14)

F Vol.66, No. 4, pp. 490-503, 2010.

2014.4.3

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