IDENTIFIKASI STRUKTUR SALURAN AIR PADA SITUS SUMBERBEJI, DESA KESAMBEN, KABUPATEN JOMBANG, MENGGUNAKAN METODE RESISTIVITAS DAN POLARISASI TERIMBAS

Abstract

The Sumberbeji found by residents of Jombang in July 2019, is thought to have existed before the Majapahit kingdom. The results of excavations carried out by BPCB found that there is an inlet water channel, which is still active today, from the west to the main structure of the site which caused the main building of the site to sink. Therefore, two geophysical methods were carried out, resistivity and induced polarization methods to map and delineate the continuity of the inlet structure, so that the presence of water sources that fill this site can be estimated. Six measurement paths, 3 paths in the direction of North - South and 3 tracks in the direction of West - East, have been carried out on the west side of the Main site building. The results of processing using the Res2DInv device produce resistivity and chargeability values from 1.40 - 308 ohm.m and 0.1 - 121 msec. Based on the correlation between the two results with geological conditions and real conditions in the field, it is interpreted that the resistivity value of 14.1 - 30.5 ohm.m and chargeability of 5.77 msec which is located at a depth of 2 meters from the surface as a water inlet structure. This structure is located under a layer of volcanic material, sand and clay with a resistivity of 66 - 308 ohm.m and a West - East direction.