KARAKTERISTIK MORFOLOGI POINT BAR PADA BAGIAN HILIR PENGGAL SUNGAI BOGOWONTO, KABUPATEN PURWOREJO, JAWA TENGAH

EKHANDOKO AJI W, Dr. Suprapto Dibyosaputro, M.Sc

2017 | Skripsi | S1 GEOGRAFI DAN ILMU LINGKUNGAN

Penelitian ini dilakukan di daerah hilir penggal Sungai Bogowonto dan sekitarnya. Lokasi penelitian memiliki suatu karakteristik morfologi yang khas akibat adanya proses geomorfologi berupa proses fluvial (erosi, transportasi, dan sedimentasi). Tujuan penelitian ini adalah: (1) Mengidentifikasi proses pengendapan sedimen di area point bar berdasarkan ukuran besar butir, (2) Mengetahui karakter perubahan morfologi point bar setiap perlapisan sedimen yang terbentuk, (3) Menganalisis ukuran butir sedimen sebagai dasar rekonstruksi morfologi point bar. Metode penelitian yang dilakukan dalam penelitian ini adalah observasi lapangan. Observasi lapangan bertujuan untuk mengidentifikasi kondisi geomorfologi dan kejadian penting yang mempengaruhi morfologi point bar. Pengambilan sampel sedimen secara vertikal dilakukan pada 2 titik dan secara horizontal dilakukan pada 3 titik. Sampel sedimen tersebut selanjutnya diuji di laboratorium dan dilakukan pengukuran fisik secara langsung. Hasil analisis dari proses pengendapan yang di area point bar, material yang terendapkan berupa pasir halus hingga pasir kasar dengan kecepatan aliran sungai sebesar 0,1 sampai 4 cm/s.

This research was conducted in the downstream segment of Bogowonto River area. The location of this research is considered to have a distinctive morphology characteristics due to the fluvial geomorphology processes (erosion, transport, and sedimentation). The purposes of the study are: (1) Identifiy the deposition process of sediments in the area of point bar based on grain size, (2) Understanding changes the characteristics of morphology of point bar based on the sedimentary layer that formed, (3) Analyze the grain size of sediment as the basis of the reconstruction of the point bar morphology. Research method used in this study was field observation. The aim of field observation area is to identification of geomorphology processes and the important events that affect the morphology of point bar. Vertically sediment sample were collected at 2 points and horizontally sediment sample were collected at 3 points. Sediment samples were analyzed in the laboratory and another sample were carried out during the physical measurement in the field. The results of the analysis of the deposition process in the area of point bar, the material were deposited is the form of fine sand and coarse sand with the flow velocity of the river are 0.1 to 4 cm/s.

Kata Kunci : Morfologi point bar, Proses Pengendapan, Ukuran Butir dan Bentuk Butir, Rekonstruksi