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Hydromorphology of the Unconfined Groundwater in the South of Klaten District (Data Before Earthquake Mei 27th 2006)
No full textThere are some characteristics and distributions of unconfined groundwater variation in the research area. Those are related to a system of water supply and consumptive use for drinking water. Variation of the groundwater characteristic depends on variation of morphology. Therefore, it is needed to delineate hydromorphology units of the regions as a base on groundwater resources management, especially for drinking water. The aims of the research are: (1) to study of the characteristic and distribution of unconfined groundwater variations base on landform units, (2) to study the factors that affect such variations, and (3) to establish the hydromorphology units of the regions for groundwater resources management, especially for drinking water. The method used in this research is landform approach and field survey. The sampling method is stratified sampling, based on landform as the analysis approach. Result of the research shows that there are some variations of groundwater characteristic at each landform. Landforms which have good groundwater characteristic are Hydromorphology Unit of Fluvio Volcanic Plain of Young Merapi (except Bayat region) and Hydromorphology Unit of Volcanic Foot Plain of Young Merapi. At those units, there are good quality of groundwater, bicarbonate water (hydrochemical type I), having low electric conductivity, shallow of water table, low in fluctuation, and middle to fast class in aquifer permeability. Those units are the most potential unconfined groundwater resources management for drinking water. The units which have poor groundwater characteristic are Hidromorphology Unit in Bayat Region, including Undulating Alluvial Plain, Fluvio Volcanic Plain of Young Merapi, and Swamp Alluvial Plain. Generally, the groundwater quality is medium to poor, the hydrochemical type is Va (initiation process of connate water) and type III (evaporate water), shallow up to medium of water table, and low to middle class of aquifer permeability. The taste of groundwater is brackish to saline with high concentration of chloride
Radar Data for Identifying the Characteristics of Tropical Forest Stands
Get PDFRadar is one of remote sensing technology which utilizes active electromagnetic energy and are able to provide information about the characteristics of forest stand. This study utilized JERS-1 and ERS-1 radar images to analyze the relationship between the radar backscatter and forest stand characteristics such as Diameter Breast Height (DBH), basal area, and canopy cover. This research was conducted in Jambi Province, Bungo Tebo District, Sumatra, Indonesia. The research site covered the forest concession, Suku Anak Dalam, the area adjacent to Pelepat and Batang Tebo River, and Kuamang Kuning village. Gamma Map Filter with 7 x 7 window size was applied to reduce speckle noise of the SAR images (ERS-1 and JERS-1). This study found out the positive significant correlation between basal area and DBH with JERS-1 radar backscatter (i.e., r = 0.75 and r = 0.70), while ERS-1 radar backscatter has correlation (r = 0.64) with the canopy cover
Kualitas Air Hujan dan Faktor Lingkungan yang Mempengaruhinya
No full textHujan merupakan masukan dalam sistem hidrologi. Ditinjau dari kualitasnya dibandingkan dengan air aami lainnya, air hujan merupakan air paling murni dalam arti komposisinya hampir mendekati H2O. Namun demikian, pada hakekatnya tidak pernah dijumpai air hujan yang betul-betul hanya tersusun atas H2O saja, berbagai faktor lingkungan telah mempengaruhi kualitas air hujan tersebut. Pencemaran udara yang terjadi di kota-kota besar, baik yang berupa buangan gas maupun emisi dari kendaraan bermotor. Serta buangan gas dari pabrik telah mempengaruhi kualitas air hujan yang jatuh di daerah kota. Air hujan di daerah pantai juga terpengaruh oleh laut dengan segala aktifitas dan komposisi airnya. Di daerah gunung api yang masih aktif air hujan juga dipengaruhi oleh aktifitas tersebut. Masing-masing lingkungan tersebut di atas mempengaruhi komposisi air hujan. Kajian kualitas air hujan dilakukan dengan mengambil hasil penelitian yang dilakukan oleh peneliti sebelumnya di daerah pulau Jawa, namun demikian hasil penelitian yang dilakukan di luar negeri juga digunakan sebagai pembanding
Lahars in Java: Initiations, Dynamics, Hazard Assessment And Deposition Processes
Get PDFLahar has been applied as a general term for rapidly flowing, high-concentration, poorly sorted sediment-laden mixtures of rock debris and water (other than normal streamflow) from a volcano. Lahars are one of the most destructive phenomena associated with composite volcanoes, which are dominant in Java Island. Resulting deposits of lahar are poorly sorted, massive, made up of clasts (chiefly of volcanic composition), that generally include a mud-poor matrix. The aim of this research is threefold: to discuss the initiation of lahars occurrences, their dynamics, to assess the hazard and to analyse the deposition. Lahars are either a direct result of eruptive activity or not temporally related to eruptions. Syn-eruptive lahars may result from the transformation on pyroclastic flows or debris avalanches which transform to aqueous flows (e.g. at Papandayan in November 2002); They may be also generated through lake outburst or breaching (e.g. at Kelut in 1909 or 1966), and through removal of pyroclastic debris by subsequent heavy rainstorms. Post-eruptive lahar occurs during several years after an eruption. At Merapi, lahars are commonly rain-triggered by rainfalls having an average intensity of about 40 mm in 2 hours. Most occur during the rainy season from November to April. Non-eruptive lahars are flows generated without eruptive activity, particularly in the case of a debris avalanche or a lake outburst (e.g., Kelut). A lahar may include one or more discrete flow processes and encompass a variety of rheological flow types and flow transformations. As such, lahars encompass a continuum between debris flows and hyperconcentrated flows, as observed at Merapi, Kelut and Semeru volcanoes. Debris flows, with water contents ranging from 10 to no more than about 25% weight, are non-newtonian fluids that move as fairly coherent masses in what is thought to be predominantly laminar fashion. However, the relative importance of laminar versus turbulent regime is still debatable. Hyperconcentrated streamflows contain 25- to about 40%-weight-water; these flows possess some yield stress, but they are characteristically turbulent. Hazard-zone maps for lahar were produced for most of the the Javanese volcanoes, but these maps are on too small-scale to meet modern zoning requirements. More recently, a few large-scale maps (1/10,000 and 1/2,000-scale) and risk assessments have been completed for a few critical river systems at Merapi
Geomorphologycal Study for Flood and Mass Movement Occurrence at Parang Sub Village, Paranggupito District, Wonogiri Regency
Get PDFThe aim of this study are knowing factors that impacts to flood and mass movement hazard at karst region. Area of this study are covering Parang Sub Village, Ngasem, Paranggupito District, Wonogiri Regency. To achieve this objective, geomorphic approaches (static, as well as dynamic environmental geomorphology) were analyzed, using survey and secondary data collection. Results from this study are describe that Parang is a karst depression and had water accumulated from Parang boundaries area as upper landform. Mass movement at study area is caused by saturation of soil by water after rainfall. Supported by steep slope impact sliding mass movement. Based on the priority, to change the water running direction and will not concentrate to Parang Depresion, there are need the water-massbank stability. This bank will prevent the soil mass to stable
Acknowledgement for Reviewers in 2016
No full textThe editors of Forum Geografi would like to express their sincere gratitude to the following reviewers for assessing manuscripts in Volume 30 2016. Prof. Dr. Junun Sartohadi, Universitas Gadjah Mada, IndonesiaProf. Dr. Ir. Hidayat Pawitan, Department of Geophysics and Meteorology, Bogor Agricultural University, IndonesiaDr Muhammad Kamal, UGM, IndonesiaSupari, BMKG Indonesia, Indonesia; Universiti Kebangsaan Malaysia, School of Environmental and Natural Resource Sciences, Bangi, MalaysiaMuhammad Haikal Karana Sitepu, University of Leeds, United KingdomDr. Yanto, Civil, Universitas Jenderal Soedirman, Indonesia R Muhammad Amin Sunarhadi, Universitas Muhammadiyah SurakartaDr. Sukamdi, IndonesiaDr. Peter Oberle, Institute for Water and River Basin Management (IWG)Karlsruhe Institute for Technology (KIT)KarlsruheGermany, GermanyProf. Dr. Muhammad Aris Marfai, Universitas Gadjah MadaDr. Pramaditya Wicaksono, Cartography and Remote Sensing Dept. of Geographic Information Science Faculty of Geography Universitas Gadjah Mada, IndonesiaDr. Sushil K. Joshi, Indian Institute of Remote Sensing (India), IndiaDr. Djati Mardiatno, UGM, IndonesiaDr. Purnama Budi Santosa, Gadjah Mada University, IndonesiaDr. Donaldi S. Permana, Center for Research and Development Indonesian Agency for Meteorology Climatology and Geophysics (BMKG); Byrd Polar and Climate Research Center and School of Earth Sciences, Ohio State University, Columbus, Ohio, USA, IndonesiaA Cipta, Geological Agency of Indonesia, Jalan Diponegoro No. 57, Bandung 40122, Indonesia Australian National University, Research School of Earth Sciences, Building 142, Mills Road, Canberra, ACT 0200, Australia, AustraliaDr Takanori Horii, Research and Development Center for Global Change (RCGC), Strategic Research and Development Area, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan, JapanHari Agung Adrianto, Institute Pertanian Bogor, IndonesiaDr. Adriana García-Rama, Department of Land, Environment, Agriculture and Forestry, University of Padova, Italy, ItalyDr. Kuswaji Dwi Priyono, Fak Geografi UMS, IndonesiaDr. Rini Rachmawati, Faculty of Geography, Universitas Gajah Mada, IndonesiaDr. Dyah R Hisbaron ,Faculty of Geography, Universitas Gajah MadaDr. Saut Sagala, Intitut Teknologi Bandung, Indonesia We greatly appreciate the contribution of expert reviewer, which is crucial to the journal’s editorial decision-making process and to the quality of the work that we publish.
Ibnu Battutah dan Perkembangan Ilmu Geografi di Indonesia
Get PDFlbnu Battutah sebagai seorang geografiwan muslim dan pengembara dunia atau journey geografi mempunyai kemampuan hebat dalam mengbasilkan karya besar yang dikagumi oleh dunia Barat. Dengan perjalanannya, bagian wilayah Indonesia telah dikunjungi sebanyak dua kali yakni pada tahun 1345 dan tahun 1346. Oleh karena itu dalam perkembangan ilmu geografi di Indonesia, sumbangan Ibnu Battutah tidak dapat diabaikan begitu saja. Hal ini mengingat babwa Battutah, sebagai geografiwan tertentu telah mencatat hasil-hasil perpelancongan geografisnya di Indonesia, khususnya di Samudera Pasai, Sumatera. Sekilas tentang biografi Battutah dan sumbangannya terhadap Geografi Indonesia disajikan dalam makalah ini
Pemahaman Karakteristik Hujan Sebagai Dasar Pemilihan Model Hidrologi (Studi Kasus di Das Bengawan Solo Hulu)
No full textThe research was conducted at the Upper Bengawan Solo Catchment, which was categorized as critical catchment. The problems of flood and drought became the main issue, and need to be handled sooner, therefore it need hydrological modelling to coupe the problems. As we know that the role of rainfall as an input to the model is very significant parameter in generating output (discharge), then the objective of this research is to know the rainfall characteristics. The rainfall distribution in the research area can be known by doing the spatial analysis, especially using Kriging method. It does the rainfall mapping for a certain duration to describe the spatial rainfall distribution. It uses the rainfall data from 20 rainfall stations with 5 minutes interval recording. It does the inter-stations correlation analysis on the amount of rainfall and the distance of inter-stations. The significant level used in this study is 5%. The result shows the tendency that the more of the station number decreased, the smaller the rainfall correlation coefficient inter-stations are. It can be meant that the numbers of the rainfall stations in catchment area have optimum number of gauge. The coverage area for each station is 13 km2 when we use 5’s minute interval data. Most of the rainfall which have intensity 30 mm/hr occur at minute 20th to 125th. As much as 17.5% of these rainfall have randomly distribution. There is a significant relationship (R2=65.2%) between daily maximum rainfall and minimum values of inter-stations correlation coefficient Base on above results it is very important to consider that in chosing the size of catchment area for hydrological modeling it should be related with its rainfall chracteristics
Perbandingan Pendapatan, Curahan Jam Kerja, dan Tenaga Kerja Usaha Tani Tebu Rakyat Intensifikasi (TRI) dengan Usaha Tani Padi di Desa Karangmojo Kecamatan Tasikmadu Kabupaten Karanganyar Tahun 1992/1993
Get PDFProgram Tebu Rakyat Intensifikasi (TRI) adalah program nasional yang mulai dilaksanakan sejak dikeluarkannya Inpres Nomor 9 Tahun 1975. Mengingat arti pentingnya program TRI sebagai program nasional dan kelompok sasaran yang dituju yakni para petani, maka penelitian ini bertujuan untuk mengukur besarnya perbandingan pendapatan petani dari usaha tani TRI dengan pendapatan petani dari usaha tani padi. Penelitian ini juga bertujuan untuk mengukur besarnya curahan jam kerja yang dimanfaatkan dari masing-masing cabang usaha tani di Desa Karangmojo, Kecamatan Tasikmadu, Kabupaten Karanganyar. Dalam penelitian ini metode yang digunakan yakni metode survai dan penentuan sampel dilaksanakan secara sampling. Sampel wilayah dan sekaligus sebagai daerah penelitian, ialah ditentukan secara purposife. Responden dalam penelitian ini ialah petani yang berusaha pada TRI, petani padi, dan buruh tani. Pengambilan responden dilakukan dengan cara mengambil 55 responden, terdiri dari Kelompok I sebanyak 11 sampel petani TRI dan padi, Kelompok II sebanyak 27 sampel petani TRI dan padi, dan Kelompok III sebanyak 23 sampel petani TRI dan padi. Data yang diambil dalam penelitian ini yakni data primer dan sekunder ditambah data yang diperoleh melalui wawancara bebas kepada pamong penduduk yang ada hubungannya dengan penelitian ini. Jenis data primer yang dikumpulkan berupa pendapatan petani dari usaha tani TRI dan usaha tani padi. Data sekunder yang dikumpulkan antara lain data penduduk, luas penggunaan lahan, pengairan, curah hujan dan pengolahan TRI beserta besarnya rendemen tebu. Hasil penelitian ini menunjukkan bahwa pendapatan dari usaha tani TRI lebih kecil daripada pendapatan usaha tani padi (pendapatan usaha tani padi banyak Rp. 2.297.363,90 sedangkan usaha TRI Rp. 7.927.866,12). Curahan jam kerja (jam kerja dan tenaga kerja) yang dimanfaatkan dari usaha tani TRI lebih kecil daripada usaha tani padi (jumlah jam kerja usaha tani padi sebanyak 2.237,29 jam dan usaha TRI sebanyak 7.937,95 jam, jumlah tenaga kerja usaha tani padi 758 orang dan usaha TRI 7 05 orang). Disamping, itu ada keluhan perihal persoalan-persoalan yang dihadapi oleh para petani sistem target glebagan, yang tanpa disadari pertimbangan-pertimbangan, perhitungan kadar rendemen tebu tidak jelas dan potongan-potongan yang tidak jelas pula
The Role of Geomorphology in Phisical Geography and its Application in Research
No full textGeomorphology as a part of earth sciences has a already known for along time, however the development and application is relatively slow, especially in Indonesia. There is a tendency that the concept as well as the application of geomprphology will increase rapidly. The aims of this paper are to discuss the concept of geomorphology. The role of geomorphology in the physical geography studies and its application research activities. Geomorphology deal with land form as subject of study and stressed on relief, processes, materials (lithology and its structure), and chronology has important role in the physical geography. Geomorphology be able to support of other sciences related to physical environment such as geology, pedology, hydrology, and archaelogy. In the practical application, geomorphology can be used in engineering purposed and regional development planning. In the research activities geomorphology can be used as basic frame work to determine sample areas, and also can be used as frame work to land resources evaluation with land form unit as land mapping unit or evaluation unit.