scholarly journals ANALISIS PENGINDERAAN JAUH DAN PEMODELAN 3D FAULT FRACTURE DENSITY (FFD) DALAM PENENTUAN ZONA PERMEABILITAS PERMUKAAN DI WILAYAH PANAS BUMI GUNUNG TAMPOMAS, JAWA BARAT

2021 ◽  
Vol 16 (2) ◽  
pp. 99-118
Author(s):  
Abizar Adi ◽  
Agus Didit Haryanto ◽  
Johanes Hutabarat ◽  
Dewi Gentana
Keyword(s):  
Fracture Density ◽  
Aster Gdem

Wilayah Gunung Tampomas yang terletak di Kecamatan Buahdua, Kecamatan Conggeang, dan Kecamatan Tanjungkerta, Kabupaten Sumedang, Jawa Barat dipilih sebagai daerah penelitian karena diperkirakan memiliki potensi panas bumi dengan hadirnya manifestasi panas bumi berupa mata air panas di sekitarnya. Kemunculan manifestasi berhubungan dengan zona permeabilitas yang dikontrol oleh struktur geologi. Kelurusan punggungan dan lembah diamati dan dianalisis menggunakan citra penginderaan jauh ASTER GDEM dan peta Rupa Bumi Indonesia (RBI), skala 1:25.000. Tujuan penelitian untuk mengetahui hubungan antara permeabilitas dengan kemunculan manifestasi panas bumi di daerah penelitian. Metode penelitian dengan melakukan analisis penginderaan jauh dan Fault Fracture Density (FFD) menggunakan pemodelan 3D micromine software. Hasil analisis penginderaan jauh dengan azimut penyinaran dari 0˚, 45˚, 90˚, 135˚ dan altitude 45˚ memperlihatkan pola utama kelurusan punggungan–lembah yang diinterpretasikan sebagai patahan memiliki arah relatif barat laut-tenggara dan timur laut-barat daya. Indikasi struktur geologi di lapangan diperlihatkan oleh morfologi bentuk punggungan lembah, di beberapa tempat memiliki tebing curam membentuk gawir sesar dan faset segitiga. Hasil analisis FFD di daerah penelitian memiliki tingkat permeabilitas yang bervariasi dengan nilai FFD rendah (0,00–3,00 km-1), sedang (3,00-6,00 km-1) dan tinggi (6,00–9,33 km-1). Manifestasi panas bumi muncul pada zona permeabilitas yang memiliki nilai FFD sedang hingga tinggi yang ditandai oleh warna jingga dan merah. Dari pemodelan 3D micromine software terhadap zona permeabilitas dan ploting mata air panas di permukaan terlihat secara jelas kemunculan mata air panas ke permukaan difasilitasi oleh patahan yang berkembang di daerah penelitian.

BEDROCK CLIFFS, COLLUVIAL SLOPES, AND FLUVIAL RELIEF COUPLED VIA FRACTURE DENSITY AND GRAIN SIZE

2017 ◽  
Author(s):  
Roman A. DiBiase ◽  
◽  
Matthew W. Rossi ◽  
Alexander B. Neely
Keyword(s):  
Grain Size ◽  
Fracture Density

Impact of Climatic Change on an Arid Watershed: Nahal Yael, Southern Israel

1979 ◽  
Vol 11 (2) ◽  
pp. 153-171 ◽  
Author(s):  
William B. Bull ◽  
Asher P. Schick
Keyword(s):  
Climatic Change ◽  
Sediment Yield ◽  
Fracture Density ◽  
Dense Networks ◽  
Valley Fill ◽  
Water And Sediment ◽  
Desert Varnish ◽  
Gravel Size ◽  
Induced Changes ◽  
Geomorphic Surfaces

The Nahal Yael basin is underlain chiefly by schist, amphibolite, and granite. Thin (generally <1 m thick), grussy colluvium which covered the lower portions of granitic hillslopes in the late Pleistocene has now been stripped completely, causing marked contrasts in outcrop morphologies, even where there is no contrast of fracture density or petrologic characteristics. Formerly mantled slopes are now smooth and crumbly, and lack desert varnish. Previously unmantled slopes are rough and craggy, and varnished but little weathered. Such stripping suggests a change from a semiarid to a drier and/or warmer climate. Slopes underlain by amphibolite responded similarly to the climatic change, but the amphibolite was more deeply weathered, and the colluvium was only partially stripped. The least stripping of colluvium occurred on schist hillslopes, partly because schist outcrops require more rain to generate runoff, and partly because angular blocks of schist require larger flows for transport, compared to other slope lithologies. The stream subsystem responded to the climatically induced changes in the discharge of water and sediment from the hillslopes. Increase in sediment yield caused valley alluviation in the early Holocene, and a decrease in sediment yield later in the Holocene caused entrenchment of the valley fill. More granite and amphibolite gravel-size particles are transported now than when the hillslopes were extensively mantled. Dense networks of trails are not common on Holocene geomorphic surfaces, but are present on remnants of Pleistocene surfaces.

Quality Assessment of Globally Available Digital Elevation Model (DEM) for Mountainous Region

2021 ◽  
Vol 5 (1) ◽  
pp. 11-21
Author(s):  
Sangay Gyeltshen ◽  
Krisha Kumar Subedi ◽  
Laylo Zaridinova Kamoliddinovna ◽  
Jigme Tenzin
Keyword(s):  
Digital Elevation Model ◽  
Vertical Displacement ◽  
Satellite System ◽  
Topographic Map ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
The Government ◽  
Elevation Model ◽  
The Individual

The study assessed the accuracies of globally available Digital Elevation Models (DEM’s) i.e., SRTM v3, ASTER GDEM v2 and ALOS PALSAR DEM with respect to Topo-DEM derived from topographic map of 5m contour interval. 100 ground control points of the elevation data were collected with the help of kinematic hand held GNSS (Global Navigation Satellite System), randomly distributed over the study area. The widely used RMSE statistic, NCC correlation and sub-pixel-based approach were applied to evaluate the erroneous, correlation, horizontal and vertical displacement in terms of pixels for the individual Digital Elevation Model. Following these evaluations, SRTM DEM was found to be highly accurate in terms of RMSE and displacement compared to other DEMs. This study is intended to provide the researchers, GIS specialists and the government agencies dealing with remote sensing and GIS, a basic clue on accuracy of the DEMs so that the best model can be selected for application on various purposes of the similar region.

Sign in / Sign up

Export Citation Format

Share Document