Hazard Maps is a map represented dangerous area which is highly likely to suffer natural disaster. It is used to avert natural disaster such as eruption. “Hazard” means cause, dangerous material or obstacle.

　Volcanic hazard map is a map represented volcanic hazard and information about disaster prevention. Now, there are 29 volcanic hazard maps about active volcano in Japan.
　Eruption does not usually occur like weather phenomenon. So even we live in Japan called volcanic country, encountering with eruption is rare. If we hadn’t experienced it for long years, the wisdom about volcanic disaster would cease completely. Most people encountering volcanic disaster for the first time will become confused.
　Moreover, in the case of volcano, differently from earthquake, spend much time from starting eruption to finishing, and it is difficult to ascertain when it finish. Occurred disaster have so variety that the type of eruption such as fall of ash, pyroclastic and lava.
　 For these reasons, to make hazard map correspond to various volcanic disasters needs a lot of information.
　 We think it is important that we make hazard map about volcanic disasters in order not to repeat the past tragedy.

　National Land Agency made “Volcanic Disaster Danger Area Forecast Figure Creation Guideline” about 4 volcano including Mt.Fuji in 1992 and manualized hazard map. However, it did not spread among local government very much. It is because that there were budget problems to make hazard maps and volcano grasped its characteristic was few. What do you think you can do to spread hazard map larger?

　To predict when and where volcanic disaster occur is difficult, moreover, there are a lot of difficult things to predict ; what happen next to erupt, when it finish.
　The way to predict where and how erupt is only to examine the volcanic action in the past and guess. To examine the history of eruption, we can refer to historical documents or pictures, including secondhand information and estimate by future generations, it lacks credibility. About order eruption, we have only the way to examine ancient remains and geology survey.
　In this way, the map made from the result of field survey is “disaster map.” When we want to make hazard map, we decide the eruption period referred to, eruption scale and eruption phenomenon presumed.
　Then, we can make volcanic hazard map. So let’s see making hazard maps concretely.
　In the case of making hazard map about Mt.Fuji, two types of map, “drill map” and “probability map,” were made.

　 Drill map is a map represented range suffered each simulated disasters. This map enable us to have concretely image to where spread influence by a specific eruption. However, just this map, there is problem about misunderstanding that only a specific eruption on simulation will occur, other type of eruption will not occur. It is important that this is not true.

　 Probability map is a map gathered results of simulation about every place that have a probability of eruption. That is to say, this is a map represented zones which have likelihood of suffering each volcanic phenomenon, a map represented that the probability of suffering damage is high or low about the entire area around the mountain.
　We can know where is very dangerous about eruption when we see a probability map. However, these maps also have some problems that it may give misunderstanding that every place will be suffered damage and it is difficult to understand because of complicated diagrams.