KARAKTERISTIK MORFOMETRI SEBAGIAN DAS CIJAMPANG SEBAGAI RESPON VARIASI LITOLOGI DI KECAMATAN KADUPANDAK, KABUPATEN CIANJUR, PROVINSI JAWA BARAT
Daftar Isi:
- ABSTRACT Basically, the research is located in the Cijampang watershed and surrounding area. Administratively, it is lies within Kadupandak sub-district, Cianjur sub-province, West Java, Indonesia. According to Java’s physiographic map by Van Bemmelen (1949), this area can be included as a part of Southern Mountain Zone. This research is being held as a purpose to observe the respon of into the lithology on the research area. The activity of the research covers the analysis of the geologycal data through Geological Reigion Map (scale 1:25000) and surface data sampling, remote sensing analysis, statistical test, and morphometry characteristic analysis. Drainage watershed morphomethry is indices of geomorphologic aspect used to analyzed the characteristic of lithological variation. Several parameter of drainage watershed morphometry were measured, i.e. linear morphomethry such as river order, length of order segment, cummulative range of river segments (Lu), bifurcation ratio (Rb), and areal morphomethry such as drainage density (Dd). Drainage watershed morphomethry is indices of geomorphologic aspect used to analyzed the characteristic of lithological variation. Several parameter of drainage watershed morphometry were measured, i.e. linear morphomethry such as river order, length of order segment, cummulative range of river segments (Lu), bifurcation ratio (Rb), and areal morphomethry such as drainage density (Dd). The validation of quantitative value of morphometric parameter was been calculated by statistic method approach, that include normality test, homogenity test and t-test.The data of result analysis and field survey are verified using t-test. The test shows significant difference among both lithology, where “tcalculation > ttable”. It is mean that there were difference between morphomethry parameter of each lithology.The result of the morphometry caracteristic analysis in units of Tmbp and Tmbx show that the landscape characteristic texture is modarate with birds feather watershed. In the other hand, Tpt unit have rough texture of landscape and radial watershed shape. Based on the linear morphometry caracteristic (Rb), the units which have many river bifurcation is Rmbp and Tmbx unit, nevertheless Tpt unit have less river bifurcation. Beside to differ character of those both lithology, Rb value can also show most developing stuctural influence in Tpt unit area. ABSTRAK Daerah penelitian mencakup sub DAS Cijampang dan sekitarnya yang secara administratif termasuk di Kecamatan Kadupandak dan sekitarnya, Kabupaten Cianjur, Provinsi jawa barat. Berdasarkan Van Bemmelen (1949), fisiografi daerah penelitian terletak pada Zona Pegunungan Selatan. Penelitian ini bertujuan untuk mengetahui respon karakteristik morfometri terhadap litologi daerah penelitian. Kegiatan penelitian dilakukan dengan analisis data geologi melalui Peta Geologi skala 1:25000 dan Peta Geomorfologi skala 1:25000, analisis pengindraan jauh, analisis uji statistik dan analisis karakteristik morfometri. Morfometri DAS merupakan perhitungan aspek-aspek geomorfologi yang dapat menganalisa karakteristik dari variasi litologi. Beberapa parameter morfometri yang dihitung, diantaranya, linear morfometri, seperti orde sungai, panjang dari segmen sungai, total panjang dari semua segmen sungai (Lu), dan nisbah percabangan/bifurcation ratio (Rb), serta areal morfometri, seperti drainage density (Dd)dan bentuk sub DAS. Hasil dari analisis linear maupun areal morfometri menunjukkan bahwa terdapat perbedaan nilai antara sub DAS pada setiap satuan batuan. Nilai-nilai dari parameter tersebut divalidasi melalui uji statistika, yang mencakup uji normalitas, uji homogenitas dan uji beda. Hasil analisis data-data tersebut diverifikasi melalui t-test (uji beda). Pengujian menunjukkan perbedaan signifikan antara kedua litologi, dimana “thitung> t tabel”. Hal ini mengartikan bahwa memang terdapat perbedaan pada parameter morfometri pada litologi masing-masing. Hasil dari analisis karakteristik areal morfometri (Dd) pada Tmbp dan Tmbx menunjukan karakteristik bentang alam bertekstur sedang dengan bentuk sub DAS berupa bulu burung. Sedangkan pada Tpt mempunyai karakteristik bentangalam bertekstur kasar dan bentuk sub DAS radial. Dari analisis karakteristik linear morfometri (Rb) banyaknya percabangan sungai terbentuk pada satuan Tmbp dan Tmbx, sedangkan Tpt memiliki percabangan sungai yang lebih sedikit. Nilai Rb tersebut selain dapat membedakan sifat-sifat dari kedua litologi, juga dapat menunjukkan pengaruh struktur yang lebih berkembang pada daerah Tpt.