LANDSLIDE SUSCEPTIBILITY ANALYSIS AFTER THE MAY 2006 EARTHQUAKE AROUND PLERET AND PUNDONG, BANTUL REGENCY, YOGYAKARTA

PROCEEDINGS JOINT CONVENTION BALI 2007
The 32^nd HAGI, The 36^th IAGI, and The 29^th IATMI Annual Conference and Exhibition

LANDSLIDE SUSCEPTIBILITY ANALYSIS AFTER THE MAY 2006 EARTHQUAKE AROUND PLERET AND PUNDONG, BANTUL REGENCY, YOGYAKARTA

Wiyarti Wardhani*, Efriyansyah*, Ahmad Junaidi* and Dwikorita Karnawati**

* B.Eng Student in Geological Engineering Department, FT UGM Yogyakarta
** Lecturer in Geological Engineering Department, FT UGM Yogyakarta

ABSTRACT

The earthquake of Yogyakarta on last May 27^th 2006 with a magnitude 5.9 Richter scale has destroyed hundreds of thousand building along Yogyakarta and part of Central Java which had horrifying effect that caused more than 6000 peoples died.

The earthquake has also caused several landslides and rockfalls which occurred at the slope of the Southern Mountain that lays along the eastside the Opak Fault. Those landslides and rockfalls have become a threat for the local people along districts Pundong - Pleret. The earthquake has also created and re-opened many existing cracks, which generate new problems of unstable slopes. These threats will be intensifying when the rainy season occurs as the rainwater infiltrates the cracks and reduces the shear strength; later these processes increase the landslide susceptibility of the slope.

The level of landslide susceptibility depends on geological conditions such as morphology, geological structures, rock types and its physical characteristics, stratigraphy and groundwater. This research has purposes to study those geological conditions along Pleret – Pundong area and has done by using aerial photographs interpretation and geological mapping. The results are given by a landslide susceptibility map which has benefits for local authorities to enhance the land use managements and to establish hazard management strategies.