Fuzzy logic application for cave entrance identification

Fuzzy logic allows ambiguity and obscurity. Fuzzy logic explains that truth is not an absolute way. Rather, it presents data in ranges. This becomes the advantage of fuzzy logic in categorizing spatial data in a natural way. Cave entrance identification in karst landscape has an important value because caves are the alternative water resources and conservation region for biota biodiversities, archaeological heritage, and other research for the different discipline of science. This research was conducted in Gunung Sewu Karst Landscape with varied physiography, Ponjong and Semanu District, Gunungkidul Regency. The purpose of this research is to examine the accuracy of fuzzy logic in identifying cave entrance. This research is an integration between geographic information system and remote sensing. Alos Palsar imagery is processed to produce drainage density, slope, and elevation region, while Sentinel 1 imagery processing produces lineament density. Other spatial data used in this research include monthly rainfall data and geology formation. All variables in raster format are reclassified using fuzzy membership and then overlaid with fuzzy overlay. The result is that cave entrance is found in the region with high fuzzy logic value range. Fuzzy logic has high accuracy in identifying cave entrance in Ponjong and Semanu District, Gunungkidul Regency.