Index of Active Tectonic Assessment: Quantitative-based Geomorphometric and Morphotectonic Analysis at Way Belu Drainage Basin, Lampung Province, Indonesia

The occurrence of subduction zones caused by the collision between the Eurasian-Western Indonesia Plate due to an increase tectonic, volcanic and magmatic activities along Sumatra Island. This study covers the area of Way Belu Drainage Basin, located near Bandar Lampung City, Lampung Province, southern part of Sumatra, Indonesia. The area composes of a complex geological structure as the result of tectonic activities. In this study, geomorphic indices assessment such as morphometric and morphotectonic quantitative analysis are undertaken to identify the Index of Active Tectonics (IAT). The morphometric analysis uses Drainage density (Dd) and Ratio of bifurcation (Rb). The value of Dd respectively from 1.45 to 4.05, Rb from  2 to 10. While the morphotectonic analysis uses basin shape index (Bs), valley floor width-valley height ratio (Vf), and asymmetry factor (AF). The value of Bs from 1.27 to 6.25, Vf   from 0.16 to 3.30, and AF from 22.73 to 83.77 in ranges which is derived average IAT value is 2.20. It may considered that at the Way Belu Drainage Basin has moderate to high tectonic activity. From the joint measurement results on the fracture zone express that the main pattern of faults has trend NWW-SSE, NE-SW, NNE-SSW, NW-SE, and W-E directions. Furthermore, based on the combination of the quantitative geomorphology indices assessment which is supported by remote sensing and field assessment shows that those features closely related to the Semangko Fault System with the NNW-SSE fault trend parallel to its fault

The Dynamics of the Developing Calcarenite Member of Pamutuan Formation In Cintaratu Area, Pangandaran, West Java

The investigated area is located in Cintaratu, Parigi District, Pangandaran Regency in the Southeastern part of Southern Mountain of West Java. The rock unit in the investigated area is described as the Calcarenite Member of the Pamutuan Formation. The present study applying detailed lithologic and paleontologic description reveals five lithologic units. Combining the field method with microscopic analysis leads to the verification of the age and environments of this carbonate rocks. The study concludes the development of reef complex in Early Mid Miocene, followed by the high energy of the dynamic environment producing the fragments of the lime clasts embedded in the packstone, indicates the deposition in the fore slope. The regression took place and moved the deposition environment to the low-energy condition at the back of the reef, producing bioclastic packstone containing larger foram. Rising seawater level amplified the dynamics of the seawater in mid-Middle Miocene. The formation of planktic packstone marked an initial transgression phase that was well-represented as regional transgressive in Southeast Asia. This phase continued until interbedded calcareous mudstone and sandstone were produced. Finally, in Late Mid Miocene the sea level regressive accumulated coarse materials of calcarenite grain size containing fragments of larger foram within shallower deposition environment. The NNW-SSE elongated distribution of five units of Calcerinite Member pointed out the configuration of Middle Miocene coastal line. In Early Middle Miocene, various carbonate rocks formation was primarily controlled by tectonic activities. Afterward, the rock deposition affected by the regional sea level rise and drop during Mid to Late Middle Miocene. The detailed description of the Calcarenite Member, therefore, contributed to the understanding of the paleogeography of Mid Miocene age and the dynamics of the environmental deposition

Tectonic Geomorphology of Upper Cimanuk Drainage Basin, West Java, Indonesia

The upper Cimanuk drainage basin is an inter-mountain basin. It is surrounded by volcanoes such as Mt. Tampomas, Mt. Guntur, Mt. Dano, Mt. Kamasan, Mt. Papandayan, and Mt. Cikuray. The objective of this research is to identify the degree of tectonic activity based on quantitative geomorphology analysis. Data are obtained from a topographic map, Digital Elevation Model, geological map, and field observation. Various morphometric variables are bifurcation ratio (Rb), drainage density (Dd), and mountain front sinuosity (Smf) index. The integrated analysis of morphometric and field data provides evidence of tectonic activity in Cimanuk drainage basin. Their streams have 1st until seventh order. The research area is proved to be an active tectonic area. This is confirmed by values of Rb, Dd, and Smf showing that some area in Cimanuk drainage basin has been affected by the tectonic activity. Rb values are ranging from 0.74 to 3.99, Dd values are ranging from 0.53 to 7.20, and Smf index area ranged from 1.2 to 1.6. These values can be classified into a medium class of tectonic activity level. The geological structure can be found in the middle to downstream of Cimanuk drainage basin and showed by primarily northwest-southeast trends. On the other hand, drainage pattern such as rectangular and trellis can reflect geological structures. Rectangular control is by joint and fault structure whereas trellis by dipping or folded sedimentary rocks. The Jatigede Reservoir is located in a strongly deformed area, so monitoring is necessary to reduce the impact of the disaster if some of the faults in the area are active again

Analisis Faktor-Faktor Yang Berhubungan Dengan Tingkat Adopsi Pengelolaan Tanaman Terpadu Pada Usahatani Padi Sawah” (Suatu Kasus di Desa Mekarhurip Kecamatan Talaga Kabupaten Majalengka)

Penelitian dilaksanakan di Desa Mekarhurip Kecamatan Talaga Kabupaten Majalengka, dari bulan Juli sampai September 2014. Tujuan Penelitian ini adalah untuk mengetahui : 1).Faktor-faktor yang diduga berhubungan dengan tingkat adopsi petani pengelolaan tanaman terpadu (PTT), 2). Hubungan adopsi petani dengan komponen Pengelolaan Tanaman Terpadu (PTT) padi sawah,   3).Hubungan antara faktor-faktor yang diduga berhubungan dengan tingkat adopsi petani Pengelolaan Tanaman Terpadu (PTT) padi sawah.Metode yang digunakan dalam penelitian ini adalah metode survei. Pengambilan sampel penelitian menggunakan metode acak sederhana (simple random sampling) pada populasi Kelompok Tani yang mengikuti kegiatan sekolah lapang Pengelolaan Tanaman Terpadu (PTT) padi sawah yaitu Kelompok Tani Sadahurip yang berjumlah 18 orang dan kelompok Tani Pangkalan yang berjumlah 16 orang di Desa Mekarhurip Kecamatan Talaga Kabupaten Majalengka.             Hasil Penelitian Menunjukan terdapat hubungan yang signifikan atau cukup kuat antara faktor-faktor tingkat adopsi petani dengan pengelolaan tanaman terpadu pada usahatani padi sawah.Hubungan inovasi termasuk kategori tinggi, saluran komunikasi termasuk kategori tinggi, kegiatan promosi termasuk kategori tinggi, jenis keputusan inovasi termasuk kategori tinggi.Kata Kunci :Pengelolaan Tanaman Terpadu, Kelompok tani, Tingkat Adops

PERANAN KOMUNITAS LOKAL DALAM PERENCANAAN PENGEMBANGAN GEOSITE DI KAWASAN GEOPARK BELITONG

This research is aimed to determine how the local community as geosite operator in making geosite development planning in Belitong Geopark. The research method is a descriptive study with a qualitative approach where the local community becomes the main source of research information. This research is not based on hypothetical but operational definition concepts analysis that have been formulated based on research questions. However, the mathematical analysis is used through the “Weight Scoring System” Technique or weighted assessment system to analyze the patterns and meaning of relationships between the categories. Meanwhile, a review of the literature is still undertaken to determine the theories that have been applied in related research. Data is collected by the observation techniques, documentation, and interviews. This research was conducted in 4 (four) Geosite locations: 1) Bukit Peramun Geosite in Sijuk Sub-District of Belitung Regency, 2) Juru Sebrang Geosite in Tanjungpandan Sub-District of Belitung Regency, 3) OpenPit Namsalu Geosite in Kelapa Kampit Sub-District of East Belitung Regency and 4) Tebat Rasau Geosite in Simpang Renggiang Sub-District of East Belitung Regency. With the purposive sampling technique, there are 16 respondents that are distributed in proportionately for every research location. The study have found that local communities generally have a good ability to structure and formulate Geosite development planning but still have to enhance in the future by optimizing knowledge, participation and development planning skill through human resource development (HRD) strategies in geosite management in accordance with the top 10 focus area of UNESCO Global Geopark.Penelitian ini bertujuan untuk mengetahui bagaimana masyarakat setempat sebagai pengelola geosite membuat perencanaan pengembangan geosite di Kawasan Geopark Belitong. Dalam hal ini masyarakat setempat menjadi sumber utama informasi penelitian. Metode penelitian yang digunakan adalah studi deskriptif dengan pendekatan kualitatif. Penelitian ini  tidak didasarkan pada pengujian hipotetis tetapi dengan menggunakan analisis terhadap definisi operasional konsep yang telah dirumuskan berdasarkan pertanyaan penelitian. Namun demikian, peneliti juga melakukan analisis matematika menggunakan Teknik “Weight Scoring System” atau sistem penilaian berbobot untuk menganalisis pola dan arti hubungan antar kategori. Sementara itu, peninjauan literatur masih tetap dilakukan untuk mengetahui teori-teori yang telah diterapkan dalam penelitian terkait. Instrumen pengumpulan data menggunakan teknik observasi, dokumentasi, dan wawancara. Penelitian ini dilakukan di 4 (empat) lokasi Geosite yang terdiri dari 1) Geosite Bukit Peramun di Kecamatan Sijuk Kabupaten Belitung, 2) Geosite Juru Sebrang di Kecamatan Tanjungpandan  Kabupaten  Belitung, 3) Geosite OpenPit Namsalu di Kecamatan Kelapa Kampit Kabupaten Belitung Timur dan 4) Geosite Tebat Rasau di Kecamatan Simpang Renggiang Kabupaten Belitung Timur. Dengan teknik "purposive sampling", maka jumlah Informan yang digunakan adalah sebanyak 16 orang yang didistribusikan secara proporsional untuk  setiap lokasi penelitian. Penelitian ini menemukan fakta bahwa masyarakat lokal pada umumnya memiliki kemampuan yang baik untuk menyusun dan merumuskan perencanaan pengembangan Geosite namun tetap berpotensi untuk lebih ditingkatkan dengan mengoptimalkan pengetahuan, partisipasi dan keterampilan teknis dalam perencanaan melalui strategi peningkatan kapasitas sumber daya manusia (HRD) dalam pengelolaan Geosite sesuai dengan top 10 fokus area UNESCO  Global Geopark