| Abstract | It is well-known that there exists a very attractiv e volcano situated in Central Java and Yogyakarta, Indonesia, called Mount Merapi. Deposit s produced by its activity in Sleman Regency, Yogyakarta can be divided into four rock u nits, namely Ancient Merapi, Middle Merapi, Recent Merapi, and Modern Merapi. The erupt ion of Mount Merapi, in the year 2010 was categorized as the biggest eruption during last thousand years. The type of eruption was changed from Merapi type in the activi ty period of 2006 and before to become the combination of Vulcanian type and Pelean type. Due to the activities of the volcano that is very intensive, it can be underline d that threats of geohazard to people living in surrounding areas of Yogyakarta is the im pact of volcanic eruptions. Therefore the georisk of the area is indeed. Geohazards in th e study area are related to volcanic activities, namely lava flow, pyroclastic flow, ash fall, and lahar. There are four districts that able to be reached by pyroclastic flow, includ ing Turi, Pakem, Cangkringan, and Ngemplak districts. All of districts in the study a rea are threatened by ash fall, such as Turi, Pakem, Cangkringan, Tempel, Sleman, Ngaglik, Ngemplak, Minggir, Sayegan, Mlati, Gamping, Godean, Depok, and Kalasan district s. While areas which threatened by lahar are Turi, Pakem, Cangkringan, Tempel, Ngaglik , Ngemplak, and Kalasan districts. By applying scoring method on the geohazard vulnera bility, threats, and risks, the study area can be classified into three classification, t hose are high, moderate, and low. |
