| dc.description.abstract | Managing an area for further planning requires information on risk level of area from natural hazard. Since May 29th 2006, a sea of hot mud has been gushing from the ground in Sidoarjo, East Java which caused economic, social, health and environmental impacts. Determining vulnerable area of hot mud volcano is important to provide information on the extent of the areas affected by the hazard. Vulnerability analysis requires set of factors determining dangerous level of particular area from a defined hazard source. Vulnerability analysis for natural hazard also deals with vagueness arising from expert judgment on related parameters. The objectives of this research were to develop multi-criteria evaluation method using fuzzy analysis approach for mud volcano vulnerable area and to develop mud volcano vulnerable map using proposed method. This research handles imprecision and subjectiveness involved in expert knowledge by using Fuzzy Analytical Hierarchy Process (AHP). The alpha cut analysis and lambda function was performed in Fuzzy AHP process to assess the confidence level of experts about their preference. The method was then applied to generate mud volcano vulnerability for settlement area in Sidoarjo. The criteria used in the evaluation consist of subsidence, bubble gases, mud flooded and water quality. The experts that give their judgment in form of Pairwise Comparison Matrix (PCM) represent all elements of the society such as The National Sidoarjo Mudflow Mitigation Team (BPLS), Settlement Agency of Sidoarjo, Centre of Environmental Geology, academic disaster researchers and the public as a victim of Lapindo mud. Having established Fuzzy AHP to obtain criterion performance, the spatial analysis was done by applying this performance to criterion layer to create vulnerability area. The sensitivity analysis of the method was analyzed by using alpha cut (values 0.4, 0.6 and 0.8) and lambda function (values 0, 0.5 and 1). Performing these alpha cut and lambda value showed the highest sensitivity could be observed at alpha 0.4 and lambda 0. The comparison of vulnerability map resulted from applying Fuzzy AHP method at 100% confidence level with impacted area prepared by BPLS showed that these two maps have different class of vulnerability. The result of multi-criteria analysis showed that settlement areas located in impacted area were mostly categorized as high and moderate vulnerable class, while impacted area prepared by BPLS was categorized as high hazardous area. However, the surface area of the merged class Z1 and Z2 from vulnerability analysis covered area was almost same with impacted area prepared by BPLS. | id |
