Electronic Theses and Dissertation

Kawasan Situs Benteng Inong Balee merupakan situs warisan budaya yang berada
pada lereng tebing pantai dan mengalami ancaman kerusakan akibat erosi, serta
potensi longsor yang dapat mempengaruhi kestabilan lereng dan struktur arkeologi.
Penelitian ini bertujuan untuk mengetahui litologi penyusun lereng dan
mengidentifikasi zona berpotensi longsor berdasarkan model resistivitas 2D di
kawasan Situs Benteng Inong Balee, Aceh Besar. Metode yang digunakan adalah
geolistrik resistivitas 2D dengan konfigurasi Wenner-Schlumberger. Data hasil
pengukuran diolah menggunakan perangkat lunak inversi untuk menghasilkan
penampang distribusi resistivitas bawah permukaan. Hasil penelitian menunjukkan
bahwa variasi nilai resistivitas bawah permukaan berhasil digunakan untuk
mengidentifikasi tiga lapisan utama penyusun lereng, yaitu lempung pasiran dengan
nilai resistivitas 27,4–83,4 Ωm, pasir gampingan dengan nilai resistivitas 83,4–314
Ωm, dan batugamping kompak dengan nilai resistivitas 314–910 Ωm. Litologi
bawah permukaan didominasi oleh batugamping kompak yang diselingi oleh
lapisan pasir gampingan dan lempung pasiran pada bagian dangkal. Interpretasi
model resistivitas 2D juga menunjukkan adanya zona berpotensi longsor yang
dicirikan oleh lapisan lempung pasiran dan zona resistivitas rendah yang
berkembang di antara massa batugamping kompak. Zona tersebut diinterpretasikan
sebagai area yang mengalami pelapukan, rekahan, sehingga membentuk zona
lemah yang dapat menurunkan kestabilan lereng. Keberadaan zona lemah yang
teridentifikasi pada kedua lintasan menunjukkan adanya kontinuitas kondisi bawah
permukaan yang berpotensi menjadi jalur pergerakan massa batuan. Berdasarkan
kondisi litologi, morfologi lereng yang curam, serta pengaruh , kawasan Benteng
Inong Balee diinterpretasikan memiliki potensi gerakan massa berupa longsoran
batuan (rock slide) yang dapat memengaruhi kestabilan lereng dan berpotensi
mengancam kelestarian struktur arkeologi di kawasan situs.
Kata Kunci: Benteng Inong Balee, Metode Geolistrik, Potensi Longsor, Res2dinv,
Wenner- Schlumberger.

The Benteng Inong Balee Site is a cultural heritage area located on a coastal cliff slope that is threatened by erosion and potential landslides, which may affect slope stability and the preservation of archaeological structures. This study aims to identify the slope-forming lithology and delineate potential landslide zones based on a 2D resistivity model in the Benteng Inong Balee Site, Aceh Besar. The method employed was a 2D electrical resistivity survey using the Wenner–Schlumberger array configuration. The acquired data were processed using inversion software to generate subsurface resistivity distribution models. The results indicate that variations in subsurface resistivity values successfully identified three main lithological layers: sandy clay with resistivity values ranging from 27.4–83.4 Ωm, calcareous sand with resistivity values of 83.4–314 Ωm, and compact limestone with resistivity values of 314–910 Ωm. The subsurface is predominantly composed of compact limestone, overlain by calcareous sand and sandy clay in the shallow zone. The interpretation of the 2D resistivity model also revealed potential landslide zones characterized by sandy clay layers and low-resistivity zones developed within the compact limestone mass. These zones are interpreted as areas affected by weathering and discontinuities (fractures), forming weak zones that may reduce slope stability. The occurrence of weak zones on both survey lines indicates the continuity of subsurface conditions that may act as pathways for rock mass movement. Based on the lithological conditions, steep slope morphology, and the influence of weathering and water infiltration, the Benteng Inong Balee area is interpreted to have the potential for mass movement in the form of a rock slide, which may affect slope stability and pose a threat to the preservation of archaeological structures within the site. Keywords:Inong Balee Fortress, Electrical Resistivity Method, Landslide Potential, Res2DInv, Wenner–Schlumberger.