Oleh :  Ahmad Faiz MUBAROK, Agung SETIANTO1) dan Tim PT. Asi Pudjiastuti Geosurvey 2)
1)Departmen Teknik Geologi, Fakultas Teknik, Universitas Gadjah Mada

LiDAR telah banyak dimanfaatkan untuk pemetaan skala detail, yang dapat dioptimalisasikan untuk perencanaan tata letak kota, pembangunan sarana
infrastruktur, penentuan zonasi wilayah banjir dan zonasi wilayah bencana dan juga pemetaan geologi. Namun, aplikasi LiDAR untuk geologi masih jarang
dilakukan di Indonesia, terutama yang berkitan dengan data intesity. LiDAR dapat memberikan data yang sangat detail karena resolusi spasial yang tinggi
sehingga dapat digunakan dalam interpretasi geologi. Oleh karena itu, dalam penelitian ini akan dikaji mengenai aplikasi LiDAR dalam penentuan batuan
dan kondisi geologi di daerah penelitian.

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By: Agung SETIANTO1) and SOETAAT2)
1)Department of Geological Engineering, Faculty of Engineering, Gadjah Mada University, Indonesia
2)Department of Geodetic and Geomatics Engineering, Faculty of Engineering, Gadjah Mada University, Indonesia

In order to reduce the urgent disaster due to Mt. Bawakaraeng Caldera wall collapse, the present condition of caldera wall in detail is needed to be mapping. This caldera wall is
an inaccessible and unstable area, because the wall face is very steep, about 800 meters in height and more than 1,000 meters of the width, and located at the top of Mt.
Bawakaraeng. The caldera wall was collapsed about ten years ago and millions cubic materials, mainly sand and rock, slide down to Jeneberang River as sedimentation.

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By : Dr. Agung Setianto, S.T., M.Si. and  Dr. Ibrahim Djamaluddin

The ground motion prediction from specific seismic source faults plays an important role in prevention of earthquake disasters. The three-dimensional (3D) fault at subsurface layer provides spatial information on underground characteristics by the factor of the geometry of faults such as depth, width, dip and strike direction which defined from the base information by engineering measure on the ground surface. In this paper, the geoprocessing method by specified algorithm process within Geographic Information System (GIS) technology has been developed for creating a 3D fault layer to be applied in all faults, simultaneously. In this geoprocessing method, the geometry of 3D polygon data structure as 3D fault layer is derived from the geometry of polyline data structure as fault lines. The fault lines were determined usually by referring to the lineaments. Besides, the fault information such as fault dip and depth was obtained from ground measurement. The algorithm process for the geometrical transformation from surface lines into 3D polygons was applied by the geoprocessing method, automatically. A method to estimate the 3D fault layer with a higher accuracy was divided into 3 steps: a) the fault’s depth and width was not uniform, therefore proposed a topography classification of lineaments were conducted using the topographical data as first step; b) the classified topographical geometric fault’s were analyzed by the transformation of the geometry from the boundary of polylines into the 3D polygons using the dip and strike orientation in the GIS projection system; and c) finally, the transformed boundary of 3D polygons were converted into GIS shapefile of 3D polygons referring to the topographical surface elevation. As the investigation of the capability of this method, the lineaments in the designed area were evaluated by modeling the 3D fault layers. This method provided the 3D fault databases within GIS in the consideration for the regional ground motion prediction. Furthermore, the 3D fault database was applied by the GIS method to the ground motion prediction simulation.

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Indra Arifianto ⁽¹⁾, Kartika Palupi Savitri ⁽¹⁾, Muhammad Rachmat Fadhil Priana ⁽¹⁾ and Agung Setianto ⁽¹⁾

⁽¹⁾Department of Geological Enginnering, Universitas Gadjah Mada.

ABSTRACT

The research area is located in Camba-Camba Village, Batang, Jeneponto, South Sulawesi Province, Indonesia. This area is included in the the Indonesian Government ‘development acceleration program for underdeveloped regions’. This research area shows a flow ridge volcanic morphology consisting of volcanic breccia, tuffaceous sand, and laharic clay deposit from Lompobatang Volcanic Formation. The geological condition leads to a scarcity of groundwater in the area, which makes looking for a great groundwater source is challenging. On the other hand, such a groundwater source is needed to fulfil the water demands of plantation and rice field irrigation, particularly in the dry season. The geoelectric or resistivity method was used in this study to determine the location and depth of groundwater aquifers. The resistivity method used was the vertical electrical sounding (VES) “Schlumberger” method which aims to identify the variation of subsurface rocks resistivity value against depth. Through an inversion resistivity modeling, the true resistivity value in this area ranges from 0.87 to 6117 Ωm. There are five groups of subsurface rocks that could be identified based on these values, namely claystone aquiclude, shaly sand aquitard, tuffaceous sandstone aquifer, volcanic breccia aquitard-aquifuge, and lava aquifuge. Each group, respectively, showed a resistivity value of 0.87-10.63 Ωm, 12.74-22.91 Ωm, 18.83-58.25 Ωm, 62.46-159.5 Ωm, and 414-6117 Ωm. Based on the results of the correlation and modelling of these five groups, a drilling site location was set near the JPT 02 resistivity measurement point, where the model showed an aquifer at the depth of 50 meter. The presence of this aquifer was confirmed by the drilling.

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by : Agung SETIANTO+, Tetsuro ESAKI*, Yasuhiro MITANI**,
Ibrahim DJAMALUDDIN*** and Hiro IKEMI****
(Received May 8, 2009)
Abstract
The occurrence of the surface movement is the main focus of the
study regarding to the gold & copper underground block caving mining
in Papua, Indonesia. The underground mining has brought some
environmental problems on the terrain surface such as the lowering of
the elevation followed by growing of the waste pile as the result from
the failure of the rock slope.
In this study, the surface movements due to the underground mining
were analyzed by using the aerial photogrammetry method and the
Geographic Information System (GIS) technology. The detected surface
subsidence ranging from 1.5 to 2 meter and the development of the
sedimentation area has been identified in which the maximum deposit
thickness is about 2 meter. In addition, the correlations between
extraction thicknesses over the overburden versus ground movement
have been studied in order to find out the influence of some geological
conditions in the development of the surface changing.
The surface movement induced by underground mining causes some
serious environmental impact not only above the extraction zones but
also the surrounding areas. Some environmental impacts due to the
surface movement are reviewed and discussed in this paper in order to
describe the current situation of the underground mining in Papua,
Indonesia

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ITC (The Faculty of Geo-Information Science and Earth Observation), University of Twente, Belanda bersama Fakultas Teknik, Universitas Gadjah Mada (UGM) dan perusahaaan komersial penyedia layanan LiDAR Indonesia PT. ASI Pudjiastuti Geosurvey (PT. APG) melangsungkan survei udara di atas area potensial panasbumi dekat Bajawa, Kepulauan Flores, Nusa Tenggara Timur, Indonesia. Tujuan utama survei ini adalah untuk mendapatkan data udara gabungan dari data medan LiDAR dengan presisi tinggi dan data suhu permukaan untuk memetakan ekspresi permukaan dari potensi panasbumi yang mendasarinya. Perolehan data dari survei tersebut akan menjadi yang pertama di Indonesia.

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Penginderaan Jauh adalah ilmu, seni dan teknik untuk memperoleh informasi suatu objek, daerah, dan/atau fenomena melalui analisis data yang diperoleh dengan suatu alat tanpa harus kontak langsung dengan objek, daerah, atau fenomena yang dikaji (Lillesand & Kiefer, 1994 : 1;Bates & Jackson, 1987 : 434).

Letak Indonesia yang berada pada pertemuan antar lempeng tektonik menjadi penyebab utama Indonesia rawan terjadi bencana geologi. Bencana geologi yang sering melanda wilayah Indonesia meliputi erupsi gunungapi, gerakan tanah (tanah longsor), gempa bumi dan tsunami. Hal tersebut membuat penduduk harus tetap siaga dan tanggap dalam menghadapi bencana. Banyak hal yang bisa kita tempuh untuk mengurangi risiko bencana, salah satunya dengan cara mencukupkan informasi dan pengetahuan kita tentang bencana yang kerap terjadi di negeri ini, dengan cara yang mudah dan cepat. Seiring perkembangan zaman, teknologi informasi komputer dan smartphone terus berkembang dari hari ke hari, sehingga mudah bagi setiap orang untuk mendapatkan berbagai informasi dengan cepat. Salah satu teknologi yang dapat membantu untuk mendeteksi bencana alam dan bagaimana cara mitigasinya adalah dengan menggunakan penginderaan jauh. Dengan menggunakan data penginderaan jauh, wilayah yang sulit untuk diakses oleh penduduk sekalipun dapat terdeteksi dengan aktual dan cukup baik tanpa kontak langsung dengan objek atau daerah tersebut.

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Beberapa hari yang lalu masyarakat di daerah Kota Bandung di kejutkan dengan adanya banjir Cileuncang yang datang tiba-tiba dan mengalir sangat deras. Video datangnya air pun di rekam oleh sebagian warga Bandung dan menjadi viral di media sosial. Tidak hanya sampah yang hanyut dalam banjir tersebut tetapi harta benda berupa kendaraan bermotor pun ikut hanyut tak terselamatkan oleh dahsyatnya banjir tersebut.

Hujan deras dan lama yang turun sepanjang hari Senin (24/10), mengakibatkan banjir besar yang tak pernah terjadi sebelumnya. “Ini akibat meluapnya sungai Citepus, dan bobolnya irigasi Citepus. Meluapnya sungai juga disebabkan oleh dangkalnya sungai dan banyaknya sampah yang menyumbat aliran sungai. Sementara drainase perkotaan tidak mampu menampung aliran permukaan dari hujan yang lebat menyebabkan banjir parah,” kata Haryadi pula. (sumber : bbc.com)

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I Made IM Brunner, Ph.D

Department of Environmental Engineering

Universitas Bakrie, Jakarta, Indonesia

Jl. H.R. Rasuna Said Kav.C-22. Jakarta 12920

Email: made.brunner@bakrie.ac.id

Dr. Agung Setianto

Department of Geological Engineering

Faculty of engineering, Universitas Gadjah Mada, Yogyakarta

Email: agung.setianto@gmail.com

Abstract

Merapi, the most active volcano in Indonesia, sits on the northern part of Yogyakarta province where about 1.5 million residents live. In 2006 short after eruption, Merapi area was hit by a 5.9 magnitude earthquake that destroyed the Yogyakarta’s natural barrier, known as Geger Boyo.  The pyroclastic flow threat from Merapi becomes more imminent ever since. The Merapi eruption in 2006 and 2010 also brought up social drama when a local key person with several of his followers rejected the government’s evacuation mandatory. Those occasions could happen because the government who rely more on technological equipment failed to build effective communication with the local community. The government with an obligation to save people live have a tendency to give direct orders that need to be obeyed. On the other hand, local community has their own wisdom in dealing with the event, which could be more influential for them.

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Pedoman Penyusunan

PERATURAN KEPALA BADAN NASIONAL PENANGGULANGAN BENCANA NOMOR 02 TAHUN 2012 TENTANG PEDOMAN UMUM PENGKAJIAN RISIKO BENCANA,

Penyusunan Pedoman Umum Pengkajian Risiko Bencana ini ditujukan untuk :

1. memberikan panduan yang memadai bagi setiap daerah dalam mengkaji risiko setiap bencana yang ada di daerahnya;
2. mengoptimalkan  penyelenggaraan  penanggulangan  bencana  di  suatu  daerah  dengan berfokus  kepada  perlakuan  beberapa  parameter  risiko  dengan  dasar  yang  jelas  dan terukur;
3. menyelaraskan  arah  kebijakan  penyelenggaraan  penanggulangan  bencana  antara pemerintah pusat, provinsi dan kabupaten/kota dalam kesatuan tujuan.

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