Geomorphological analysis on the earthquake damage pattern: a case study of 2006 earthquake in Bantul, Yogyakarta, Indonesia

• Main Author: , Dwi Wahyuni Nurwihastuti
• Format: Article NonPeerReviewed
• Published: [Yogyakarta] : Fakultas Geografi Universitas Gadjah Mada 2013
• Online Access: https://repository.ugm.ac.id/95861/; http://repository.ugm.ac.id/digitasi/index.php?module=cari_hasil_full&idbuku=3679
• Institution: Universitas Gadjah Mada

<p>The research was carried out in Bantul District, Yogyakarta Province, Indonesia. The research objectives were: (I) to illustrate the earthquake damage pattern in Bantul, (2) to analyze the detail geomorphological characteristic of Bantul, (3) to analyze the subsurfiu:e c:haracteristicin Bantul, (4) to analyze the spatial correlation between earthquake damage pattern and geomorphological characteristic in Bantul, (5) to analyze the spatial correlation between geomorphological characteristic and subsurface characteristic in Bantul, and (6) to analyze the spatia1 correlation between earthquake damage pattern and the subsurfacecharacteristicin Bantul. <br /> Remote sensing and Geographical Information Systems techniques were applied to ana1yze the earthquake damage pattern and the geomorphological characteristic. This research employs two geophysical techniques, i.e. gmvity and geoelectric analysis for interpreting the subsurface characteristic. In addition, spatia1 correlatioo analysis was also applied to identifY the correlation between: earthquake damage pattern and geomorphological characteristic, geomorphological characteristic and subsurfiu:echaracteristic, earthquake damage patternand thesubsurfuce characteristic. <br /> The results show that the earthquake damage in Bantul District consist of 34.88% severely damage, 4.75% moderately damage, and 60.37% slightly damage. The severely and moderately damages occum:d in the plain area of Bantu!. Generally, the slightly damage occum:d in the hill and mountain area of Bantul. The general landforms of the Bantul area consist of6landforms based on their genesis, i.e. fluvial, marine, aeolian, solutiona1, denudationa1, and structural landform. In addition, the subsurfuce structure of BantuI lowland is an asymmetric gmben. The basement depth of gmben varies up to 1.6 Ian. The sediment depth is varied between 3- 150 m. The thick unconsolidated alluvium sediment occupies the eastern part of alluvial plain close to the Baturagung Range escarpment The shallow unconsolidated alluvium sediment occupies the western part of alluvial plain close to the isolated hill and the denudational hill. The shallower water level occupies fluvial, marine, and aeolian landforms. On the contrary, the deeper water level occupies structural, denudational, and solutional landforms. Moreover, the fluvial, marine, and aeolian landforms have low rock density value. These indicate that they were composed of thick unconsolidated material ofQuatemary alluvium. They were prone to earthquake. While denudationa1, structura1, and solutional landforms composed of consolidated materia1 of Tertiary rocks that have high rock density value that safe to earthquake. Based 00 the result, it can be concluded that: (1) geomorphological analysis can be applied for earthquake damage pattern analysis and (2) the research results can be applied for earthquake susceptibility analysis based on geomorphological analysis with scale range 1:100,000- 1:50,000.</p>