DEBRIS FLOW OCCURRENCE FACTORS WITH ROUGH SETS THEORY

摘要

The Island of Taiwan located on the suture of the Philippine Sea Plate and Eurasian Plate has a very fragile geology. During a typhoon or a torrential rain, the unstable geology leads to debris flow processes. Especially, in the aftermath of the earthquake on September 21, 1999, debris flow has become a recurrent and frequent phenomenon. Hence, significant research activity has been focusing on the subject of hazard prevention recently. In the past, significant efforts were dedicated to search and collect the rainfall, geological, and landform data for debris flow occurrence. Using all these information, it is possible to make informed decision as to which streams would result in debris flow. Although, these information are useful factors in deciding which streams would experience debris flow, not every factor is all that useful for the decision-making process. Hence, this will" be the salient feature discussed in this paper. The study uses 'Rough Sets Theory' to examine all the factors affecting debris flow. Numerous earlier applications of rough set theory in various scientific domains suggest that it can competently settle inexact, uncertain, or vague data. Unlike using data analysis, we can extract effective information for debris-flow using this theory of Reduce and Core and use it to set up a rule which can define the occurrence of debris flow.