関門海峡における風速・視程の出現頻度および衝突海難に及ぼす影響

Abstract

The sea collision generally occurs as the results of complicated interaction of the natural and human factors, the representatives of the former being the topography, oceanographic and meteorological conditions, and those of the latter being the conditions of navigators in connection with the ship's performance. The collision in the Kanmon Strait apt to occur under strong wind and restricted visibility. For the purpose of safety traffic management, it is necessary to represent numerically the actual states of wind, visibility, and their relation to the frequency of sea collision therein, for only insufficient information were avairable in spite of the cardinal importance of this strait for marine traffic. In the present report, the following two formulae for evaluating the frequency of sea collision in the Kanmon Strait under respective conditions were proposed, basing on the fomulae showing the distribution of wind velocity and visibility estimated from the records offered by maritime and meteorological authorities concerned. 1) For wind velocity pc[V_W]=sin^2{3.38-2.19√<V_W+1>+0.04(V_W+1)} where pc[V_W] =collision probability in the wind velocity V_w=wind velocity in meter per second 2) For visibility pc[D_V]=sin^2(1.31<D_V>^<-0.30>) where pc[D_V]=collision probability in the visible distance D_V=visible distance in kilometer