Distribution Pattern of Cave Entrance Based on Morphometry in Gunung Sewu Karst Landscape

Wonosari-Punung Formation of Middle Miocene-Pliocene and Semilir Formation of Early-Middle Miocene consists of Gunung Sewu Karst Landscape in Ponjong and Semanu District; Gunungkidul Regency. Gunung Sewu Karst Landscape has advanced karstification so that the morphology of exokarst and endokarst could be formed. Cave entrance as a marker of the endokarst morphology existence is formed by varying morphometry. This research aims to determine cave entrance distribution pattern based on a cave entrance morphometry. These research variables are cave entrance morphometry; geological formation; and geological structure (geological lineament). The analytical method uses nearest neighbour analysis (NNA) and lineament analysis. The result of this research shows that vertical cave entrance with oval; narrow; and irregularity shape have dispersed distribution pattern in Wonosari-Punung Formation. Horizontal cave entrance with irregular; rectangular; narrow; and an oval shape; have clustered pattern of distribution in the Wonosari-Punung and Semilir Formations. This research is used as a preliminary study for the development of underground water resources that are commonly found in caves of Gunung Sewu Karst Landscape