PROPAGATION AND AMPLIFICATION/ATTENUATION OF A STRONG BORE WITH TWO-DIMENSIONALITY IN PLANE SPACE

Abstract

 Aiming for the grasp of behavior characteristics of edge bore formed by tsunami, propagation and amplification/attenuation of an obliquely incident strong bore with two-dimensionality in plane space over a uniformly sloping beach are examined through the consideration and theoretical analysis of basic equations derived for the wave ray method for strong bores. As the results, it is indicated that 1) the bore propagation velocity depends on the static water depth h_0fc in front of bore, ratio h_fc/h_0fc of the total water depth h_fc of the bore front to h_0fc, bottom slope tanβ in the direction perpendicular to the bore propagation direction and slope dΔ(y)/dy of the bore height distribution Δ(y), 2) the straight propagation property of strong bore is higher than that of water wave except for some conditions, 3) the amplification/attenuation factor dh_fc/dt of h_fc depeds on h_0fc, h_fc/h_0fc, tanβ, bottom slope tanγ and water surface slope tanδ in the bore propagation direction and dΔ(y)/dy, 4) in the case that dΔ/dy=0 and bore is strong, analytical solutions of h_fc are derived and the larger tanγ and tanδ are the higher amplification height of h_fc becomes, and so on.