Pengaruh Drainase terhadap Perubahan Sifat Morfologi di Rawa Gambut Tripa Kabupaten Aceh Barat Daya

Abstract

Abstrak. Awal dari pembentukan gambut terjadi didataran rawa, yang mana pertama kali berupa aluvium dan setelahnya terjadi endapan disuatu tempat/kawasan yang lingkungannya memungkinkan terjadinya endapan tersebut, seperti sifatnya salin/payau, dan  juga  terdapat dibagian laut dangkal. Pengaturan tata air drainase pada lahan gambut harus mempertimbangkan beberapa karakteristik gambut yang sangat spesifik, diantaranya kemampuan gambut yang sangat tinggi dalam menyerap air (bersifat hidrofilik) bisa berubah menjadi hidrofobik (menolak air), jika gambut telah mengalami proses kering tak balik (irreversible drying). Parameter yang dianalisis terdiri dari pengamatan lapangan dan analisis laboratorium. Pengamatan lapangan yaitu tingkat kematangan gambut, kedalaman gambut, penurunan permukaan tanah (subsidence), warna tanah, daya menahan beban (bearing capacity) dan sifat kering tak balik (irreversible drying. Hasil pengamatan di lapangan menunjukkan bahwa pada drainase kecil, sedang dan besar yaitu: tingkat kematangan gambutnya hemik, kedalaman gambut yaitu  dalam, warna tanah gambut pada penelitian ini yaitu hitam sampai coklat kehitaman,  subsidence dipengaruhi  oleh drainase pada setiap lahan kelapa sawit yang ditandai dengan akar yang muncul di permukaan tanah, irreversible drying  pada tanah gambut masih belum mengalami kering tak balik, dan bearing capacity tanaman mengalami kondisi yang tidak tegak (condong).

Effect of Drainage on Changes in Soil Morphological Properties in the Tripa Peat Swamp Aceh Barat Daya District

Abstract. The beginning of the formation of peat occurs in the swampy plains, which is the first alluvium, and after that, there is sediment in a place/area where the environment allows the sediment to occur, such as saline/brackish, and is also found in shallow seas. The regulation of drainage water systems on peatlands must consider several very specific characteristics of peat, including the very high ability of peat to absorb water (hydrophilic) which can turn into hydrophobic (water repellent), if the peat has undergone an irreversible drying process. The parameters analyzed consisted of field observations and laboratory analysis. Field observations were peat maturity level, peat depth, subsidence, soil color, bearing capacity, and irreversible drying. Laboratory analysis, namely bulk density, water content, porosity. The results of field observations show that in small, medium, and large drainage, namely: the maturity level of the peat is hemic, the peat depth is deep, the color of the peat soil in this study is black to blackish brown, subsidence is influenced by drainage in each oil palm land which is marked by roots. that appears on the soil surface, irreversible drying on peat soil has not yet experienced irreversible drying, and the bearing capacity of plants is in a condition that is not upright (sloping). The results of the analysis in the laboratory show that in small, medium, and large drainage the average values are:  varying water content, which is between 227.0 – 480.7%, peat soil volume weight ranges from 0.22 to 0, 68 g cm-3, and the porosity of peat soil ranged from 73.84 - 91.54%.