Geological Disaster Mitigation Research Articles

Landslide Susceptibility Mapping using Geographic Information System (GIS) and Remote Sensing Data in North Luwu, South Sulawesi Province, Indonesia

Climate, topography, and rock conditions in Indonesia are relatively diverse, both physical and chemical, these conditions can cause adverse consequences such as floods, landslides, forest fires, and droughts. The Information from Volcanology and Geological Disaster Mitigation on Monday, July 13, 2020, flash floods and flow of debris due to landslides have occurred in Masamba and Baebunta, North Luwu, South Sulawesi Province. The purpose of this paper is to map the distribution of landslide susceptibility area using remote sensing and GIS data. The Method used to analyze the landslide susceptibility estimation model refers to the Indonesian Center for Agricultural Land Resources Research and Development (ICALRD). The parameters used in this model are rainfall, soil type, rock type, slope, land use, and land movement. The ICALRD Landslide Susceptibility Estimation Model in study area shows that there are three classes of landslide susceptibility, such as low, medium, and high susceptibilities. There are six subdistricts which are in medium to high landslide susceptibility, and the others are low to medium landslide susceptibility. The locations of landslides and flash floods that occurred in Masamba and Baebunta indicate areas with medium to high landslide susceptibility.

Cyclic freeze–thaw induced stiffness anisotropy of sandy silt under all-round and unidirectional freezing modes

The stiffness anisotropy of soil is a critical factor that influences the deformation characteristics of soil in landform evolution, geological disaster mitigation and engineering applications. However, the effects of freeze–thaw cycles on the stiffness anisotropy of soil have not been clearly understood. In this study, a new thermal boundary-controlled triaxial testing system equipped with bender elements is developed to investigate the effects of cyclic freeze–thaw on the stiffness of a sandy silt under both unidirectional and all-round freezing modes. It is revealed that under all-round freeze–thaw cycles, the shear wave velocity in the horizontal and vertical planes undergoes a continuous increase of 14% and 8%, respectively. In contrast, unidirectional freeze–thaw leads to a non-monotonic evolution of shear wave velocity, eventually resulting in a 3% reduction in the horizontal plane and a 16% reduction in the vertical plane after 10 freeze–thaw cycles. The increase in shear stiffness anisotropy of the sandy silt after freeze–thaw cycles is more significant in the unidirectional freeze–thaw condition (from 1.11 to 1.49) compared with the all-round freeze–thaw condition (from 1.13 to 1.19). This study illustrates the significance of unidirectional freeze–thaw in the evolution of mechanical anisotropy of soils in cold regions.

Rancang Bangun Sistem Peringatan Dini Bencana Banjir Di Kabupaten Madiun Berbasis Website Dan SMS Gateway Menggunakan Mikrokontroller Arduino

Madiun Regency is one of the districts on the island of Java, precisely in the province of East Java. Based on research from the Center for Volcanology and Geological Disaster Mitigation (PVMBG), Madiun City has several potential disasters, one of which is flooding with a high category. This is because Madiun Regency has two streams, namely Kali Sono and Kali Piring which head up on the slopes of Mount Wilis, Madiun Regency. Both times it ended in the Jerohan River in the Balerejo District, Madiun Regency which is a tributary of the Bengawan Madiun River. When heavy rains fell, parts of Madiun City were immediately inundated by flood waters. To anticipate floods, this research proposes a prototype design of a flood disaster early warning system using multiple sensors based on the Global System for Mobile Communications (GSM) in Madiun Regency. Which in the design uses the waterfall and Arduino methods. The prototype built is able to provide early warning information. The data that has been taken can be displayed on the web which functions as a monitoring system, so that officers can carry out supervision more easily and take action when the situation is dangerous. With the prototype and the system made, it is expected to be able to minimize losses caused by floods.

Predictive Displacement Models Considering the Probability of Pulse-Like Ground Motions for Earthquake-Induced Landslides Hazard Assessment

ABSTRACT Predictive displacement models (PDMs) based on the Newmark sliding block method have been widely applied in earthquake-induced landslide hazard assessment (ELHA). Pulse-like ground motions (PLGMs) can cause significant structural damage. In this study, four PDMs that consider the probability of occurrence of PLGMs (PP) were created for strike-slip and non-strike-slip events. The results demonstrate that the model with PP has greater accuracy in non-strike-slip events than the model without PP, however, the effect of PP may be disregarded in strike-slip events. This result is applicable to the ELHA and can provide a basis for post-earthquake emergency and geological disaster mitigation.

Spectral And Fractal Analysis of Volcanic Tremor at Ijen Volcano, Indonesia

A volcanic tremor is one of the seismic events that is usually recorded at the Ijen volcano. In 2014 the status of the Ijen volcano had yet to be declared normal after being critical in 2012. Many volcanic tremors are still recorded since then. This study aims at analyzing the volcanic tremors of Ijen volcano using the January to March 2014 seismic recording data obtained from the Center for Volcanology and Geological Disaster Mitigation, Bandung, Indonesia. We analyzed the spectra and fractal of volcanic tremors. Fractal and spectral analysis was conducted to investigate the dynamical system regarding the sources of the mechanism. Spectral analysis was estimated using the Fast Fourier Transform method, and fractal analysis was estimated using the regularization method. The spectra of a single volcanic tremor had frequencies of 1.1-1.5 Hz. Fractal analyzes were performed to identify dynamic systems. The fractal of a single volcanic tremor had a dimension of 2-2.3. Based on the frequency and fractal dimension values obtained, we suspect that the trigger of the volcanic tremors of the Ijen volcano is a fluid-filled crack mechanism.

Socialization of Geological Disaster Mitigation at SMAN 23 Jakarta

The purpose of this Community Service is to provide knowledge about disaster mitigation, especially the earthquake and tsunami disaster at SMAN 23 Jakarta. This activity was carried out on January 21, 2022 through a zoom meeting which was attended by students of SMAN 23 Jakarta from the MIPA and IPS majors. This activity was initiated by providing a pre-socialization questionnaire through google form which aims to determine the knowledge of SMAN 23 Jakarta students related to disaster mitigation, especially the earthquake and tsunami disaster before socialization, then carried out socialization in the form of exposure to disaster mitigation through presentations and videos, then ended by giving back the socialization evaluation questionnaire which aims to see how far the benefits felt by students and students of SMAN 23 Jakarta from the socialization that has been delivered. Through an evaluation questionnaire given to 11 students after socialization, it appears that there is an increase in the knowledge of students at SMAN 23 Jakarta, where there is an increase of 18.2% in knowledge of students and students related to the mechanism of destruction caused by earthquakes, then there is an increase of 9, 1% knowledge of students related to tips for handling in the event of an earthquake, followed by an increase of 18.2% related to symptoms and early warning of a Tsunami and an increase of 9.6% in knowledge of students and students regarding tips for handling in the event of a Tsunami. From the questionnaire, it can be concluded that this socialization activity is useful and increases the knowledge of SMAN 23 Jakarta students regarding disaster mitigation, especially the earthquake and tsunami disaster, which is then expected to be able to fortify themselves if at any time an earthquake and tsunami disaster occurs in their neighborhood.

Management of Site Evaluation: A Lesson Learnt of 10 MW HTGR Experimental Power Reactor (RDE) Project Site Licensing

In 2013, a pre-project activity of Experimental Power Reactor (RDE Project) was started. The reactor type is a High Temperature Gas-cooled Reactor (HTGR) with a 10 MWth capacity. At present the project has been postponed due to some reason, however, there was an important stage that has been achieved, regarding the site evaluation process to obtain site permits from the Regulatory Body (BAPETEN). Site evaluation is an critical activity that will guarantee the safety of nuclear facilities from natural and human induced external events as well as the safety of population and the environment due to nuclear facility accidents. Site evaluation for the RDE project has the same process as a large NPP project, considering that at the time of the site evaluation process there were no specific regulations that considered a graded approach for a mini-scale NPP. The site evaluation process includes two stages, namely 1). Site Evaluation Program (SEP) and Management System of Site Evaluation (MSSE) Approval and 2) Site Evaluation Approval. SEP is intended to establish the scope and criteria for site evaluation safety. Whereas the Site Evaluation Management System is a managerial instrument that makes site safety as the top priority in each activity and process of RDE site evaluation. BATAN as the project owner delivered the SEP document and MSSE to BAPETEN on March 10, 2014. These documents was intensively discussed by BAPETEN and BATAN to determine agreement on the scope of site evaluation, criteria and management aspects based on site safety considerations. The technical aspects that must be evaluated are seismicity, volcanic hazard, geotechnical and foundation, meteorology, hydrology, human induced events, dispersion and population distribution. This document was approved by BAPETEN on March 2, 2015. Considering the very wide scope with various fields of competence and need supporting data for evaluation, this can not be done only by BATAN experts, it must collaborate with various institution that have competence related to the site aspect. The experts that involved in the site evaluation come from Meteorology and Geophysics Agency (BMKG) for seismic and meteorological aspects, Geospatial Information Agency (BIG) to support geospatial data and ground movements/deformation, Geological Survey Center (PSG) to support geological data and geological structures, Center for Volcanology and Geological Disaster Mitigation (PVMBG) to support volcanic catalog data and volcanic hazard, University to support geotechnical, foundation and hydrology evaluation. BATAN experts from various Centers involved for evaluating topography, human induced events, dispersion, dose assessment, population distribution, emergency preparedness, and technology aspects. Data acquisition activities such as geophysics, drilling, geological mapping, volcanic mapping, hydrology, satellite imagery and digitizing processes are contracted through third parties with guidance developed by the BATAN Expert Team. Considering the very limited time and financial resources availability, in order to achieve the effectiveness of all activities, a special organization was formed to control site evaluation with the BATAN Chairman as Top Management. The Site evaluation document was submitted in two stages. The first stage is administrative completeness and it was declared administratively complete on November 15, 2015. The second step is BAPETEN assessed and evaluated the technical documents submitted to determine the acceptability of the site. The process of evaluating the site evaluation document lasts quite a long and intensive. Finally, the site permit was issued on January 23, 2017. The valuable lessons during the site evaluation project are: 1) It require the same understanding and perception between applicant and regulator regarding the site licensing process; 2) The establishment and implementation of an effective organization; 3) controlling the project schedule.

Analisis Potensi Kelongsoran pada Ruas Jalan Raya Pangalengan menggunakan Sistem Informasi Geografis

Indonesian National Board for Disaster Management (BNPB) claimed the landslide incident on 5 May 2015 in Pangalengan District caused gas pipelines owned by PT. Geothermal Star Energy exploded, 9 people died, 154 displaced and 10 houses buried. Based on the facts, it is necessary to make an effort to reduce the risk of landslides by utilizing satellite imagery. The purpose of this study was to identify potential landslides on the Pangalengan highway and make recommendations mitigation actions for the local government. The method used was using 2 estimation system models made by the Directorate of Volcanology and Geological Disaster Mitigation in 2004 and 2005. The result of the DVMBG 2004 showed the very high classification had a percentage of 97.24% and the DVMBG 2005 result showed the high classification reached 53.26% and the very high classification reached 53.26%. The potential for landslides on the Pangalengan road is 98.37%. Recommended mitigation actions were cutting slopes or making soil retaining walls or drainage channel planning.

Remote Sensing Analysis of Lineaments using Multidirectional Shaded Relief from Digital Elevation Model (DEM) in Olele Area, Gorontalo

The Gorontalo fault zone is an active fault that crosses Gorontalo Province with a movement of about 11 mm/year. The existence of this fault zone affects the morphological lineaments and offsets along its path and increases the potential of geological disaster hazards. The Olele area is located in the Gorontalo fault zone that makes it potential to landslide disaster. This study aims to analyze the lineaments of the Olele area and its surroundings. The results of this analysis will help to determine the geological structures distribution pattern that develops in the study area and its impact on the mitigation of landslide disasters in the study area. This study uses a spatial analysis method using Digital Elevation Model (DEM) image to analyze slope and lineaments data in the study area. The results of the analysis will be correlated with regional geological structures and give recommendations for geological disaster mitigation that can be implemented. The results showed that the slope class in the study area was dominated by the range of 16-35° and even in several places with a slope of 35-55°. The results of the extraction and processing of lineaments data get 203 data. The lineaments direction is relatively NNW - SSE. This direction indicates that mostly the morphologies are influenced by the existence of the Gorontalo fault zone. The existence of the Gorontalo fault zone makes this area prone to landslide disasters in the case of Gorontalo fault movement. Some prevention recommendations are to increase the slope stability level.

Crisis Management Policy of Natural Disaster

Abstract
 Indonesia is the country that has the most active volcanoes in the entire world. The Eurasian Plate, the Pacific Plate, and the Indo-Australian Plate are three active tectonic plates that cause collision zones to form these volcanoes. Indonesia is estimated to have 129 volcanoes, all of which are carefully monitored by the Centre for Volcanology and Geological Disaster Mitigation. This is done because several volcanoes in Indonesia continue to show activity. Moreover, it is estimated that more than five million people live in the "danger zone" of a volcano where they must be immediately evacuated if the mountain shows significant upward activity (Indonesia-Investment, 2019). However, efforts to reduce the risk of natural hazards remain largely uncoordinated in different types of hazards and do not necessarily focus on areas with the highest disaster risk.
 This paper uses a descriptive qualitative approach as the main writing approach and uses crisis management theory by Rosenthal, that crisis management involves efforts: (1) to prevent a crisis from occurring; (2) to prepare better protection against the impact of crisis agents; (3) to make effective responses to the actual crisis; and (4) to provide plans and resources for post-crisis recovery and rehabilitation.
 The results of this study are: (1) to accelerate forest recovery, the government can engage the community with security and welfare approach; (2) natural disaster management is the main responsibility of the government; (3) In crises due to natural disasters, form a team that is responsive to critical situations. This team was formed by involving government agencies, community leaders, and NGOs; and (4) to increase the government's capacity to reduce the impact of natural disasters, assessment of potential damage, the establishment of an early warning system, and the improvement of disaster-resistant capabilities are needed.
 Keywords: Crisis Management; Natural Disaster; Policy.

IDENTIFIKASI POTENSI LONGSOR MENGGUNAKAN SISTEM INFORMASI GEOGRAFIS DI KECAMATAN SALEM KABUPATEN BREBES

Berdasarkan BNPB, korban tanah longsor pada tanggal 22 Februari 2018 sejumlah 11 Orang meninggal dan 7 orang hilang. Longsor terjadi akibat kemiringan lereng yang curam serta bentuk material geologi yang berupa napal sehingga dapat dijadikan sebagai bidang gelincir gerakan tanah. Pengolahan data Peta geologi dan tutupan lahan berupa shapefile dilakukan clip pada daerah penelitian. Penetapan tingkat kerawanan kawasan longsor di daerah penelitian didasarkan kepada model pendugaan kawasan rawan tanah longsor oleh Direktorat Vulkanologi dan Mitigasi Bencana Geologi/DVMBG (2004).Skor = (30 % x faktor kelas curah hujan) + (20% x geologi) + (20 % x faktor kelas Erodibilitas) + (15% x penggunaan lahan) + (15 % x faktor kelas lereng). Berdasarkan penelitian yang dilakukan, daerah rawan longsor tertinggi berada di desa ciputih seluas 943 Ha dan wanoja dengan luas 684 Ha, daerah berkawasan sedang longsor berada di desa citimbang seluas 893 Ha dan wanoja seluas 708,37 Ha. Sedangkan daerah rendah longsor berada di desa Salem seluas 1193 Ha. . Faktor yang berpengaruh paling besar yaitu kemiringan lereng 46 % dan Erodibilitas 35 %. Kedua parameter ini berpotensi menyebabkan longsor.

Vegetative engineering as landslide reduction and handling alternative

This paper is prepared as the results of review study approach of landslide-affected location a week after the event and analysis of literature study. The landslide event on April 1st, 2017 that caused the death of 26 people in Banaran village on the slopes of Mount Wilis, Ponorogo, East Java, as an example of events occured due to loss of natural elements in the form of perennials. Vegetative engineering effort is one of alternatives in reducing or preventing landslides, by utilizing hardwoods with strong roots in order to withstand landslide scours. The Center for Volcanology and Geological Disaster Mitigation estimated that landslide on Mount Wilis slopes was initiated bythe absence of plant species as water absorber and land cover disappearance that led to increased critical land and environmental degradation. The purpose of vegetative engineering research was to select plants with function to prevent landslides. Type of this research was descriptive qualitative analysis through method of vegetative engineering in selecting right kind of plant species to be cultivated on the land with altitude 0-2000 MASL (Meter Above Sea Level).

Curriculum Development Training Improvement in the Competence Geological Disaster Mitigation Community Based

This research was motivated still many natural disasters in Indonesia. Geological disasters would always be an important issue in the Indonesian Nation as a consequence Indonesia's geological conditions unique region, rich in natural resources but full of potential disasters. Disaster handling required the participation of all components of the nation led to the importance of the massive dissemination of disaster information to all levels of society. The role of the community in the society was considered to be very strategic as agents of change. Unfortunately, the competence of members of the community who were still considered weak in disaster mitigation and counseling techniques became constraints the achievement of objectives disaster-conscious society. Increased competence was absolutely necessary and training could be selected as an option to improve competence. Research conducted using the method of research and development which was divided into three main stages. First, the needs analysis as a preliminary study, the second, the development of a model curriculum, and the third trials of the curriculum model to determine the effectiveness in improving the competence fields of geological disaster mitigation. This study was conducted to determine the curriculum development process proper training to improve competence in community-based geological disaster mitigation. The results showed that the model developed training curriculum based on the needs analysis proven effective in improving participants's competence to do counseling disaster mitigation. Pre-post test results showed an increase in the cognitive aspects of participants in Trial I and Trial II. Significant improvement occurred on the competence of counsel which showed a success rate of Trial II in improving the competence of counsel practice of training participants. Factors supporting the development of a model curriculum Extension Disaster Mitigation Training Community-Based Ground Motion were: (a) the competence of lecturers geological disaster mitigation; (B) the interests of members of community volunteers; and (c) the support of policy makers, while the factors that impeded the development of curriculum models were limited clump of competence training in geology, low educational background and knowledge of the geology and ground motion, and limited time.

Study on Failure Mechanism of Gongjiafang Bank Slope in Wu Gorge of the Three Gorges, the Yangtze River, China

During running period of the Three Gorges reservoir ,failure mechanism of bank slope is one of the important scientific problems of geological disaster mitigation for reservoir bank. GongJiafang bank slope is located in left of Wu Gorge in Three Gorges of the Yangtze River, where damage events appeared in 175 m experimental water storage in 2008 and 175 m normal water storage in 2011.Study shows that, GongJiafang bank slope located in the core of the Heng Shi stream anticline developes two group of tectonic fractures .The first one is unloading fracture of bank slope, whose upper part is in transfixion or intermittent transfixion status,and the second one belongs to shear shear fracture. Bank slope presents cataclastic rock mass structure ,whose water physical properties are poor. The shear strength parameters of bank slope soil reduce after being immersed, a decreas of about 52 % on cohesion, and 30 % on friction. Regional new tectonic stress field control the macroscopic law for failure of GongJiafang bank slope .Especially max2 shear zone in new tectonic stress field is consistent with the first group fracture, which strengthen progress of the unloading fracture developement .Bank slope basically appear unstable failure along with the first group fracture. About 50% unbroken lower part of unloading fracture in GongJiafang bank slope locate in reservoir water level change belt between 145m and 175m.During the reservoir water level rising, stability coefficient of bank slope decreases from 1.31 to 0.88 after being immersed, and it is inevitable for bank slope to fail suddenly. Research results for further exploration on the formation mechanism of bank landslide in the Three Gorges reservoir and its mitigation has positive significance.