STUDI KERAWANAN SEISMIK KECAMATAN TEMON, WATES, DAN PANJATAN, KABUPATEN KULONPROGO

• Main Authors: , Deasy Rimanda Cahyaningtyas, , Prof. Dr. Kirbani Sri Brotopuspito
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2012
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/98965/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=55514
• Institution: Universitas Gadjah Mada

Kulon Progo Regency is one of developing regency in Yogyakarta Province. Strategic issues related with new international airport, Tanjung Adikarto harbour, and south major road are parts of economic big development planning. Earthquake susceptibility map made as part of feasibility study. Temon, Wates, and Panjatan sub-district is selected as strategic area. The earthquake study including local effect and earthquake susceptibility maps. The local site effect study as follows: geology, geohydrology, local amplification, site frequency, and shear wave velocity. Four kinds of earthquake susceptibility are made: (1) Qualitative earthquake microzonation, (2) Peak ground accelaration map with Atkinson-Boore atenuation function based on MASW Survey, (3) Peak ground accelaration map with Atkinson- Boore atenuation function based on topography, (4) Peak ground acceleration with Kanai atenuation function. Based on its geological condition, the study area divided into 5 unit: (1) Andesite breccia unit as part of Old Andesite Formation, (2) Limestone unit as part of Sentolo Formation, (3) Clay � sand unit (alluvial origin), (4) Clay � sand unit (colluvial origin), and (5) Iron sand unit. Normal faults exist presents in the field forming minor normal faults and springs, and become the river path especially on andesite breccia unit. Clay � sand unit, based on borehole lithologic log has coarsening pattern from north to south. North parth of study area dominate with clay material. Sediment thickening present around Panjatan sub-district especially at Bojong, Depok, Wates, and Ngestiharjo village. The local site amplification value range from 1,35 to 7,56, the site frequency value range from 0,28 to 13,37 Hz, Vs30 value based on MASW survey range from 96,745 to 499,74 m/s, whereas Vs30 based on topography range from 181,95 to 651,80 m/s. Each local site condition is dependent. The high amplification area has thin Quarternary sediment layer, and the type of Tertiary sediment depend with lithological variations. Low frequency area has thick Quarternary sediment layer. Vs30 value correlate with sediment grain size, the bigger grain size, the higher Vs30 value. The four earthquake susceptibility map indicate Panjatan sub-district as the most susceptible area, due to the nearest area from earthquake source scenario. The four earthquake susceptibility maps present good correlation with sub-district damage house distribution, but these four earthquake susceptibility maps not present significant correlation with village damage house distribution. In this case, Quarternary sediment thickness becomes a very important parameter in order to get precise susceptibility level.