Sinkholes Mapping in Tanjungsari, Gunung Kidul Regency, Yogyakarta: A Preliminary Data for the Assessment of Sinkhole’s Susceptibility

Abstract

Tanjungsari district is located in Gunung Kidul Regency, Yogyakarta, known as the karst region where the dissolution process has taken place and caused some sinkhole occurrence. However, there is no any study that carry out the characteristic and the specific number of sinkholes presence in this area yet. Therefore, this study aims to create a sinkhole map in the study area with the observation of its physical characteristics based on some important data such as lithological data, geomorphological feature, existed sinkhole location as well as its physical characteristic that were collected by field observation and the secondary data evaluation. Limestone is the only lithology type was found in the study area and it is likely to be influenced by the dissolution process. Furthermore, there are more than 20 sinkholes were found with approximate 1m to 80 m in diameter and a few meters onward in depth. Some of them formed like a shallow bowl and some are vertical wall. Most of them associated with the gentle slope and the soil cover area. The results from the study will serve as important information for further detail study such as sinkhole’s susceptibility mapping.