Chun-chon city is the area that is estimated to be damaged by breaking of Dam by a flood among several natural disaster. If so, what is the way that minimize the damageulcorner There are many ones but it may be best that we take shelter from it before the breaking of Dam. Then when must we doulcorner By what instrument can we minimize the damage of people. And how do we compute the timeulcorner In this study, using buffering, overlap and network, GIS ability based on ARC/INFO. I chose six routesto take shelter outside of Chun-chon city, calculated the traffic volume of each ones, and estimated the time for decentralization of risks.