The Estimation and Analysis of the Domestic Shipping Flow in the Japan Coastal Waters

Abstract

K. Hara published the method to estimate the shipping flow between ports (The Journal of the Nautical Society of Japan, No. 52, 1974). The authors tried to use the method for all the Japanese ports. But it ended up with the results that the estimation is greatly different from the fact of the research on the coastal shipping flow performed by the Marine Safety Agency. Therefore the authors proposed the modified method in this paper. In the former method, wij-to be understood as the factor determining the degree of the relationship between port i and j-is 0(i=j) or 1(i=⃥j). But in the modified method, it is determined by the two independent parameters, the one is rij: the distance between port i and j, the other is qij: the quantity of cargoes carried between those ports. The results of the estimation using the modified method are well fit with the various facts as the first approximation. For example, the number of coastal ships except fishing boats and car ferries which are at sea in a moment is about 3500.