531

1 INTRODUCTION

Ships were significantly damaged by the Great East

JapanEarthquakeandtheensuingtsunamionMarch

11, 2011. Because Nankai Trough Earthquake and

Tokai Earthquake occurrence are highly probable in

thenearfuture,theimportanceofevacuationmeasure

for ships has become increasing. While various

measureshavebeendiscussed,ithasnotbeendoneto

clarify dangerous waters and safe place from actual

marine traffic analysis when the tsunami predicted.

To let the Tsunami go past safely, the navigators

normallynavigateshipstothedeep‐waterareathatis

sometimes said more than 200 meters (Kamaishi

Japan Coast Guard 2004). If it is not possible, they

instructabandontheshipandevacuateonthelandas

one choice. Actually, several ships are evacuated to

thesafedepthareaattheGreatEastJapanEarthquake

(Hidenari M. et al. 2011). Preliminary measures in

consideration ofthe marine traffic situation leads to

quicklyandsafelyevacuateshipstosafetydepthsea

area.

The authors introduced marine traffic analytical

methodsbasedontheGasmodel(GenF.etal.2013)

andOZT (GenF. &RuriS.2016).In this paper,one

year AIS data has been studied with both models.

Then results are compared with estimated fishery

tracksby hearing observation (Gen F. 2016). Finally,

shipsthatareactuallyheadingtoOZTareanalyzed.

2 CALCULATIONMODELS

2.1 Gasmodelbasedriskanalysis

The Gas model based calculation for the purpose of

developing Tsunami measure is introduced and

detailsareshowninGenF.&KyokoT.2015.Therisk

is become higher when more vessels exist and take

different courses in the area during the sampling

time. In this study, 1 hour average rate (TR) are

calculatedasfollows:

Development Of Analytical Method for Finding the

High Risk Collision Areas

G.Fukuda

TokaiUniversity,Tokyo,Japan

.Shoji

TokyoUniversityofMarineScienceandTechnology,Tokyo,Japan

ABSTRACT:ThetrafficconditionhasbeenanalyzedbymodelsthatarebasedonGasmodelandObstacleZone

byTarget(OZT)byusing1yearAISdataforTsunamimeasure.ByapplyingGasmodelbasedmethod,itis

possibleto analyzethe areainterms ofships’relative angle, size,speedand density.TheOZT isoriginally

developedtoshowthecollisionzoneonthetargetship’scourse. Byusing thismethodtothemarinetraffic

analysis,highpossibilityofcollisionareasareestimated.Moreover,shipsthatcoursesareheadingtoOZTare

identifiedandstudiedtheirpositionandhowlongtheyproceedcourseheadingtoOZT.

http://www.transnav.eu

the International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 11

Number 3

September 2017

DOI:10.12716/1001.11.03.20