| Abstrak/Abstract |
Assessing seismic vulnerability is crucial for disaster preparedness and urban planning, especially in regions with complex geological conditions like the Yogyakarta Basin. The devastating 2006 earthquake caused severe structural damage, numerous casualties, and significant economic losses, highlighting the need for continuous seismic vulnerability assessment. This study assessed seismic vulnerability by determining the site’s resonant frequency, the horizontal-to-vertical spectral ratio (HVSR) peak amplitude, and the ground vulnerability index across the Yogyakarta Basin. Seismic microtremors were recorded at 707 locations within the Yogyakarta Basin. The analysis employed the lognormal distribution and automated frequency domain window rejection algorithms to process the microtremor data. These methods effectively eliminated noisy windows in high-variance datasets while minimizing the unnecessary exclusion of valid windows in low-variance datasets. Areas with Kg values exceeding 10 and low resonant frequencies were considered highly vulnerable because of the potential for ground motion amplification. Such regions include Sanden, Kretek, Pundong, Bambanglipuro, Jetis, Pleret, Sewon, Berbah, Prambanan, Banguntapan, Kalasan, and parts of Yogyakarta City, Depok, Gamping, and Kasihan. The results offer valuable insights for guiding land-use planning, prioritizing mitigation efforts, and informing seismic risk management. Moreover, the findings emphasize the need for integrated seismic hazard modeling to improve resilience and preparedness across the Yogyakarta Basin. |
