Analisis GIS Terhadap Gerakan Tanah di Girimulyo, Kulonprogo, D.I. Yogyakarta, dan Kajian Faktor – Faktor Pengontrolnya

Yogi Saktyan Respati¹, Asnanto Multa Putranto¹, Azim Suwardi¹, Irien Akinina Fatkhiandari¹, dan Salahuddin Husein²

1) Student at Geological Engineering Department Gadjah Mada University, corresponding email: yogi_onmail@yahoo.co.id, asnantomp@gmail.com, azim_suwardi@yahoo.co.id, qnz_qnina@yahoo.com

2) Lecturer at Geological Engineering Department, Gadjah Mada University

Abstract

There were several landslides had occurred at Girimulyo District, Kulonprogo Regency, Yogyakarta Special Province. These suggest that this area exhibits high potential of mass movement. This research is intended to map and analyze the mass movement potentail by using two methods, i.e. qualitative and quantitative, respectively. Direct observation is on site study for internal factors (e.g. lithologies and geologic structure) and external factors (e.g slope, vegetation, and landuses). Quantitative method utilizes Geographic Information System (GIS) spatial analysis on weighted parameters, i.e. slope, lithologies, geologic structures, and landuses. The research area is mainly composed of weathered lithologies of andesit breccia and breccia tuff covering steep slopes, whilst the rainfall rate reaches up to 2205 mm/y. Both factors are presumed to be the main trigger of mass movement. Result of this research is landslide susceptibility zonation which consist ot four levels which can be used as a basic information for hazard mitigation and regional planning. There were two types of mass movement exist at this area, fall movement were predominant in andesitic intrusion, whereas flow movement mainly took place in andesitic breccias, coralline limestones, and tuffaceous siltstones. This study suggests that more attention and awareness should be paid for areas with high and very high susceptibility levels such as Tanggulangin, Talunombo, and Giripurwo, particularly during high rainy sesason

(this is abstract of my second research and paper which is submitted at 2010 International Geosciences Conference and Exsposition)

Kajian Zona Kerentanan Gerakan Tanah dengan Pendekatan Analisis GIS
pada Daerah Girimulyo, Kulonprogo, D.I. Yogyakarta

Asnanto Multa Putranto (1) , Yogi Saktyan Respati (1) , dan Salahuddin Husein (2)
1) Student at Geological Engineering Department Gadjah Mada University, corresponding email: asnantomp@gmail.com, yogi_onmail@yahoo.co.id
2) Lecturer at Geological Engineering Department Gadjah Mada University

Abstract

Landslide susceptibility zoning is often using as a basic information for hazard mitigation and regional planning. This method was applied onto Girimulyo District, Kulonprogo Regency, Yogyakarta Special Province. This study area is composed of weathered lithologies of andesite and andesitic breccias covering steep slopes, which had considerable probability for mass movement to occur. This study utilizes quantitatively spatial analysis by using Geographic Information System (GIS) on weighted parameters, i.e. slopes, lithologies, geologic structures, and landuses. Verified by existing landslides, it is expected that outcomes from this research might be used to mitigate future events. There were two types of mass movement occurred in the study area, fall movement were predominant in andesitic intrusion, whereas flow movement mainly took place in andesitic breccias, coralline limestones, and tuffaceous siltstones. Most of the events were located along a structurally weak zone on NW-SE trend. This study suggests that more attention should be paid for areas with high and very high susceptibility levels, such as Tanggulangin, Talunombo, and Giripurwo, particularly during high rainy season.

Keywords: Landslide, GIS, Girimulyo Yogyakarta.

(this is abstract of my first research and paper which is submited at Annual Convention and Exhibition of Indonesian Association of Geologists)

HAPPY NEW YEAR!!
Let's be better!

Indonesia Tuan Rumah World Geothermal Congress (WGC) 2010

(sharing informations)

Indonesia dipercaya menjadi tuan rumah pertemuan World Geothermal Congress (WGC) tahun 2010. Kongres yang akan diselenggarakan di Bali nanti merupakan pertemuan yang ke lima kalinya.World Geothermal Congress merupakan forum pertemuan bagi ilmuwan, pakar panasbumi, industri serta pihak-pihak lain yang terkait dengan panasbumi untuk bertemu, mempromosikan, menyebarluaskan informasi serta memperkenalkan teknologi terbaru dalam pengembangan panasbumi.Penunjukan Bali, Indonesia sebagai tuan rumah dilakukan setelah ditandatanganinya nota kesepahaman antara pihak International Geothermal Association [IGA] dan pihak Indonesia Geothermal Association [INAGA] yang disaksikan oleh Menteri Energi dan Sumber Daya Mineral Bapak Purnomo Yusgiantoro pada 29 April 2005. Kongres ini diadakan 5 tahun sekali mulai dari tahun 1995 di Pisa, Italy; tahun 2000 di Bepu, Japan; tahun 2005 di Antalya, Turkey dan tahun 2010 yang akan datang diadakan di Bali, Indonesia nanti.Penyelenggara WGC2010 adalah Asosiasi Panasbumi Indonesia yang didukung oleh Pemerintah Indonesia melalui Departemen Energi dan Sumber Daya Mineral [DESDM] serta dilaksanakan oleh Professional Congress Organizer [PCO] yang sudah ditunjuk yaitu Pacto Convex dibawah arahan dari pihak IGA maupun pihak INAGA. Tempat penyelenggaraan dari WGC2010 ini adalah di Bali International Convention Centre [BICC] Nusa Dua, Bali pada 25-30 April 2010.Indonesia merupakan salah satu negara yang memiliki cadangan panasbumi terbesar didunia. Sebagai negara yang memiliki banyak gunung berapi, Indonesia terbukti memiliki energi panas bumi yang sangat besar diperkirakan mencapai 27.510 MW dengan total kapasitas 1.052 MW. Potensi tersebut tersebar pada 256 lokasi.Akhir dari penyelenggaraan kongres ini diharapkan dapat menghasilkan ‘Bali Declaration’ yang akan mendorong pengembangan panasbumi pada masa yang akan datang yang merupakan energi terbarukan yang ramah lingkungan. WGC2010 ini juga akan menjadi forum yang sangat penting mengingat target pemerintah untuk menambahkan 4.700 MW dari panasbumi yang diharapkan bisa tercapai pada tahun 2014 disamping ikut mempromosikan pariwisata di Indonesia, khusus nya Bali.

Sumber:http://www.esdm.go.id

TSUNAMI
(sharing knowledges)

Hey Guys, it is the first time i wrote a blog. Since I study about geology, so i'm trying to share knowledges and experiences to all of you about geology. And hope it will gives benefits. Unfortunately i see that there's some problem for people to understand about geology clearly. One of them based on insufficient information of geology.

For example is Tsunami.You may still remember when the Yogyakarta Earthquake happened at May,2006. People were blind about what was happened. They're panic. So when issue of "Tsunami" raised,uncontrolled chaos happened. People running around,searching for higher place to save their self. Some accidents happened. People didn't care about the others, what they care was how to be saved. This condition shouldn't be happened if people had a knowledges towards this. And knowledges about geology are so related to this condition.

For example, if people know that the elevation of Yogyakarta is more than 100m above sea surface, so they will know that Yogyakarta will never be crushed by tsunami,because the highest Tsunami's wave that ever known never reach 20m above sea surface. And there will be no chaos because of issue of Tsunami.

Tsunami it self is happened because of the energy of earthquake.And the displacement of oceanic plate under sea because of energy of earthquake which transports a big mass of water.A bit confusing right? i give you a picture and let's make it simple :)

This is the picture of the displacement of oceanic plate.. and you can see some masses of water are transported.. Still difficult to understand?You can imagine you shake your hand under water, and some masses of water are transported to the other places. So this mass of transported water which transported to the land will raise as Tsunami.

As the tsunami approaches the coast and the waters become shallow, wave shoaling compresses the wave and its velocity slows below 80 kilometres per hour (50 mph). Its wavelength diminishes to less than 20 kilometres (12 mi) and its amplitude grows enormously, producing a distinctly visible wave. Since the wave still has such a long wavelength, the tsunami may take minutes to reach full height. Except for the very largest tsunamis, the approaching wave does not break (like a surf break), but rather appears like a fast moving tidal bore.Open bays and coastlines adjacent to very deep water may shape the tsunami further into a step-like wave with a steep-breaking front.When the tsunami's wave peak reaches the shore, the resulting temporary rise in sea level is termed run up. Run up is measured in metres above a reference sea level.

A large tsunami may feature multiple waves arriving over a period of hours, with significant time between the wave crests. The first wave to reach the shore may not have the highest run up.About 80% of tsunamis occur in the Pacific Ocean, but are possible wherever there are large bodies of water, including lakes.

FYI, Another things cause Tsunami are landslides, volcanic explosions, bolides and seismic activity.

Other informations should be approached to get clearer understanding about tsunami so we can get benefits towards it. And avoid more victims.Finally,I hope this information will gives benefits for us. I think it is enough for now, later information will be updated soon.

Thanks for reading :)

_yogirespati