Analysis and Evaluation of Earthquake Hazard Zones Based on Spatial Models for Regency Regional Development Bantul

Abstract

Abstract Earthquakes are a natural disaster that occur frequently in Indonesia. A region susceptible to earthquakes is the Bantul district. Buildings and infrastructure could be damaged by this disaster, especially in highly populated metropolitan areas where the Bantul Regency earthquake (Mw 6.4) on May 27, 2006, resulted in significant damage.The purpose of this research is to identify the distribution of the region’s level of stability against the possibility of an earthquake occurring, as well as the degree of compatibility between the vulnerability zone and the Development Territory Unit (SWP) of Bantul district. This research uses data collection techniques by direct observation with microtremors to calculate surface peak ground acceleration (PGA) with a value of Vs.30. The regional stability weighting matrix approach is used in this study, which is governed by Minister of Public Works Regulation Number 21 of 2007 covering Guidelines for Spatial Planning in Volcanic Eruptions and Earthquake-Prone Areas. The research results for Bantul Regency have a distribution of Vs.30 values between 175 - 350 m/s which is included in the Soft Rock (SC) category with surface peak ground acceleration (PGA) values between 0.112 g - 0.418 g. The final score for Bantul Regency is 20 - 43 which falls into the stable and less stable categories. The Development Area Unit (SWP) of Bantul Regency SWP, which is in the unstable zone, is dominantly distributed around the Opak Fault. SWP II, III, IV, and V require mitigation measures when used for residential areas. Spatial planning that is in accordance with built-up and non-built zones will be able to reduce risk factors.