Studi Variabilitas Spasial dan Pembentukan Gambut di Daerah Taman Nasional Sebangau, Palangka Raya, Kalimantan Tengah

Tirta Febrio Pramono, Prof. Dr. Ir. Ferian Anggara, S.T., M.Eng., IPM. ; Dr. Yan Restu Freski, S.T., M.Eng.

2025 | Skripsi | TEKNIK GEOLOGI

Penelitian sebelumnya terkait variabilitas gambut di Indonesia telah dilakukan pada dua lingkungan pengendapan berbeda, yakni pesisir dan intermontane. Taman Nasional Sebangau, Kalimantan Tengah, merupakan kawasan konservasi gambut tropis di topografi datar yang ideal untuk mempelajari variabilitas gambut pada lingkungan pengendapan dataran (inland). Penelitian ini bertujuan mengidentifikasi persebaran vertikal dan lateral karakteristik gambut inland di daerah tropis sebagai pelengkap studi variabilitas gambut tropis. Sebanyak 14 titik bor ditentukan menggunakan bor tangan MacCaulay. Sampel dideskripsikan berdasarkan klasifikasi tekstural tanah organik Wüst dan dianalisis menggunakan petrografi organik, analisis proksimat, ultimat, dan integrasi data penginderaan jauh. Ketebalan gambut berkisar antara 1,5–8 meter, dengan nilai Normalized Difference Vegetation Index (NDVI) antara 0,174–0,904. Ditemukan tiga jenis gambut: fibric, hemic, dan sapric. Lapisan puncak didominasi fibric yang tersusun oleh matriks organik dan maseral humodetrinite. Bagian tengah terdiri dari hemic dengan dominasi matriks dan jaringan teroksidasi (oxidized tissue), mengindikasikan proses oksidasi. Bagian dasar dan tepi didominasi sapric yang kaya jaringan kayu dan maseral textinite, mencerminkan tingkat dekomposisi yang tinggi. Secara lateral, ketebalan gambut menurun ke arah sungai dengan kadar abu meningkat terhadap kedalaman dan kedekatan tubuh air, mengindikasikan pengaruh sedimen anorganik. Kandungan sulfur yang rendah (<0>

Previously research on peat variability in Indonesia has been conducted in two different depositional environments: coastal and intermontane. Sebangau National Park, Central Kalimantan, is a tropical peat conservation area situated on a relatively flat topography, making it an ideal site for studying peat variability in inland depositional settings. This study aims to identify the vertical and lateral distribution of inland tropical peat characteristics to complement existing research on tropical peat variability. Fourteen boreholes were drilled using a MacCaulay hand auger. Peat samples were described based on the organic soil texture classificationWüstand analyzed through organic petrography, proximate and ultimate analysis, and remote sensing integration. Peat thickness ranges from 1.5 to 8 meters, with Normalized Difference Vegetation Index (NDVI) values ranging between 0.174 and 0.904. Three peat types were identified: fibric, hemic, and sapric. The upper layer is dominated by fibric peat composed of organic matrix and humodetrinite macerals. The middle layer consists of hemic peat characterized by organic matrix and oxidized tissue, indicating oxidative processes. The lower and marginal parts are dominated by sapric peat, rich in woody tissues and textinite macerals, reflecting a higher degree of decomposition. Laterally, peat thickness decreases toward the river, with ash content increasing with depth and proximity to water bodies, suggesting the influence of inorganic sediment. The very low sulfur content (<0>

Kata Kunci : Taman Nasional Sebangau, Endapan Gambut, inland, Variabilitas, pembentukan gambut