scholarly journals Microzonation of Soil Amplification Based on Microtremor, Spt and Cptu Data in Bandung Basin

2019 ◽  
Vol 29 (1) ◽  
pp. 53
Author(s):  
Anggun Mayang Sari ◽  
Eko Soebowo ◽  
Afnindar Fakhrurrozi ◽  
Arifan Jaya Syahbana ◽  
Adrin Tohari
Keyword(s):  
Scientific Information ◽  
Standard Penetration Test ◽  
Alluvial Fan ◽  
Geographical Information ◽  
Coarse Grained ◽  
Site Classification ◽  
Soil Amplification ◽  
Site Class ◽  
Soil Class ◽  
Class E

Bandung Basin consists of Sunda-Tangkuban Perahu volcanic deposit that is made of lake sediment and an alluvial fan with fine to coarse-grained materials such as clay, silt and sand. The area is surrounded by several earthquake sources such as the Lembang, Cimandiri, and Baribis Faults. Therefore, it is important to understand soil dynamic problems with respect to seismic sources and soil properties. This research aims to investigate velocity amplification of the Bandung Basin using microtremor measurements and site classification based on the Standard Penetration Test (SPT) and Cone Penetrometer Test (CPTu). Velocity amplification was analyzed using the horizonal to vertical H/V spectral ratio, and site classification was determined using and  values. Microzonation maps were developed using Geographical Information System (GIS) to determine the correlation between soil velocity amplification and site class. The results revealed that velocity amplification levels in the Bandung Basin vary with a range of 1.3 to 26.5. Site classification ranges from very dense soil and hard rock (class C), stiff soil (class D) to soft clay soil (class E). Site class E dominates the southeast part of the Bandung Basin with a high value of soil amplification. This scientific information is critical for further spatial planning focusing on infrastructure and residential building. Cekungan Bandung berasal dari endapan vulkanik Sunda-Tangkuban Perahu yang terdiri dari sedimen danau dan kipas aluvial dengan material berbutir halus hingga kasar seperti lempung, lanau, dan pasir. Daerah ini juga dikelilingi oleh beberapa sumber gempa yakni sesar Lembang, Cimandiri, dan Baribis. Oleh karena itu masalah dinamika tanah yang dipengaruhi oleh sumber seismik dan sifat tanah perlu menjadi perhatian. Tujuan penelitian ini adalah untuk mengetahui amplifikasi kecepatan tanah di wilayah cekungan Bandung dengan menggunakan alat mikrotremor dan metode site classification berdasarkan uji SPT dan CPTu. Amplifikasi kecepatan dianalisis menggunakan perbandingan rasio spektral H/V dan site classification yang diperoleh dengan menggunakan nilai  dan . Peta mikrozonasi disusun menggunakan teknik Sistem Informasi Geografis (SIG) untuk menentukan korelasi amplifikasi tanah dan site class tanah. Hasil penelitian menunjukkan bahwa tingkat amplifikasi kecepatan di Cekungan Bandung bervariasi, berkisar 1,3 hingga 26,5. Site classification berkisar dari tanah yang sangat padat dan batuan keras (kelas C), tanah kaku (kelas D) hingga tanah lempung lunak (kelas E). Hasil penelitian menunjukkan site class E mendominasi bagian selatan Cekungan Bandung dengan nilai amplifikasi tanah yang tinggi. Informasi ilmiah ini diperlukan untuk perencanaan tata ruang kedepannya, dengan fokus pada infrastruktur dan bangunan tempat tinggal.

Site Characterization Using Microtremor Array and Seismic Hazard Assessment for Jakarta, Indonesia

2019 ◽  
Vol 109 (6) ◽  
pp. 2644-2657 ◽  
Author(s):  
Mohamad Ridwan ◽  
Phil R. Cummins ◽  
Sri Widiyantoro ◽  
Masyhur Irsyam
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Soft Soil ◽  
Site Characterization ◽  
Standard Penetration Test ◽  
Alluvial Fan ◽  
Earthquake Hazards ◽  
Ground Acceleration ◽  
Site Class ◽  
Near Surface

Abstract Site characterization is one of the most important components in seismic hazard analysis because it accounts for the important effects of near‐surface geology on ground motion. It is usually quantified based on the time‐averaged S‐wave velocity (VS) for the top 30 m of the profile (VS30). In this study, we estimate the site class in Jakarta based on VS structure estimated using microtremor array observations. The results show that microtremor‐derived VS profiles agree well with standard penetration test‐derived profiles at nine sites. The site‐class estimates in the Jakarta area can be divided into two National Earthquake Hazards Reduction Program classes: (a) site class E (soft soil) located in alluvium, beach ridge, and alluvial fan deposits in northern and western Jakarta, and (b) site class D (stiff soil) found mainly in alluvial fan deposits in southeastern Jakarta. The variation of VS30 in Jakarta leads to different soil amplification factors that will impact the seismic hazard at the surface. We show that the seismic hazard resulting from selected ground‐motion models (GMMs) illustrates a clear influence of site effects at long periods (>1  s). However, the effect on peak ground acceleration and response spectra for short periods (0.2 s) appear to be less pronounced, due to the GMMs’ treatment of basin effects and nonlinear soil behavior. Available GMMs may not accurately account for such effects in the Jakarta basin, and GMMs specific to Indonesia should be developed to accurately assess seismic hazard there.

Assessment of land-use change in coastal areas through geographical information systems

2020 ◽  
Vol 13 (10) ◽  
Author(s):  
Verónica Lango-Reynoso ◽  
Karla Teresa González-Figueroa ◽  
Fabiola Lango-Reynoso ◽  
María del Refugio Castañeda-Chávez ◽  
Jesús Montoya-Mendoza
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Geographical Information Systems ◽  
Design Methodology ◽  
Scientific Information ◽  
Coastal Ecosystems ◽  
Coastal Areas ◽  
Geographical Information ◽  
Coastal Zones ◽  
Computer Based

Objective: This article describes and analyzes the main concepts of coastal ecosystems, these as a result of research concerning land-use change assessments in coastal areas. Design/Methodology/Approach: Scientific articles were searched using keywords in English and Spanish. Articles regarding land-use change assessment in coastal areas were selected, discarding those that although being on coastal zones and geographic and soil identification did not use Geographic Information System (GIS). Results: A GIS is a computer-based tool for evaluating the land-use change in coastal areas by quantifying variations. It is analyzed through GIS and its contributions; highlighting its importance and constant monitoring. Limitations of the study/Implications: This research analyzes national and international scientific information, published from 2007 to 2019, regarding the land-use change in coastal areas quantified with the digital GIS tool. Findings/Conclusions: GIS are useful tools in the identification and quantitative evaluation of changes in land-use in coastal ecosystems; which require constant evaluation due to their high dynamism.

scholarly journals Alluvial fan dynamics in the El'gygytgyn Crater: implications for the 3.6 Ma old sediment archive

2012 ◽  
Vol 8 (3) ◽  
pp. 2187-2222 ◽  
Author(s):  
G. Schwamborn ◽  
G. Fedorov ◽  
N. Ostanin ◽  
L. Schirrmeister ◽  
A. Andreev ◽  
...  
Keyword(s):  
Alluvial Fan ◽  
Coarse Grained ◽  
Lake Basin ◽  
Mass Wasting ◽  
Sandy Gravel ◽  
Modern Soil ◽  
Coarse Grained Material ◽  
Near Shore ◽  
Ice Content ◽  
Flooding Events

Abstract. A sedimentological program has been conducted using frozen core samples from the 141.5 m long El'gygytgyn 5011-3 permafrost well. The drill site is located in sedimentary permafrost west of the lake that partly fills the El'gygytgyn Crater. The total core sequence is interpreted as strata building up a progradational alluvial fan delta. Four structurally and texturally distinct sedimentary units are identified. Unit 1 (141.5–117.0 m) is comprised of ice-cemented, matrix-supported sandy gravel and intercalated sandy layers. Sandy layers represent sediments which rained out as particles in the deeper part of the water column under highly energetic conditions. Unit 2 (117.0–24.25 m) is dominated by ice-cemented, matrix-supported sandy gravel with individual gravel layers. Most of the unit 2 diamicton is understood to result from alluvial wash and subsequent gravitational sliding of coarse-grained material on the basin slope. Unit 3 (24.25–8.5 m) has ice-cemented, matrix-supported sandy gravel that is interrupted by sand beds. These sandy beds are associated with flooding events and represent near-shore sandy shoals. Unit 4 (8.5–0.0 m) is ice-cemented, matrix-supported sandy gravel with varying ice content, mostly higher than below. It consists of slope material and creek fill deposits. The uppermost meter is the active layer into which modern soil organic matter has been incorporated. The nature of the progradational sediment transport taking place from the western and northern crater margins may be related to the complementary occurrence of frequent turbiditic layers in the central lake basin as is known from the lake sediment record. Slope processes such as gravitational sliding and sheet flooding that takes place especially during spring melt are thought to promote mass wasting into the basin. Tectonics are inferred to have initiated the fan accumulation in the first place and possibly the off-centre displacement of the crater lake.

Quaternary evolution of the intermontane Val d'Agri Basin, Southern Apennines

2009 ◽  
Vol 72 (3) ◽  
pp. 431-442 ◽  
Author(s):  
Irene Zembo ◽  
Laura Panzeri ◽  
Anna Galli ◽  
Riccardo Bersezio ◽  
Marco Martini ◽  
...  
Keyword(s):  
Alluvial Fan ◽  
Optically Stimulated Luminescence ◽  
Coarse Grained ◽  
Subsequent Stage ◽  
Alluvial Fans ◽  
Southern Apennines ◽  
Short Period ◽  
Depositional Systems ◽  
Geochronological Constraints ◽  
Osl Age

AbstractOptically Stimulated Luminescence (OSL) enables the chronology of the late Pleistocene evolution for the Val d'Agri intermontane basin of Southern Apennines to be defined in the frame of Mediterranean geodynamic and climate changes. Quartz sand from braided floodplain and alluvial fan depositional systems was analyzed using the coarse-grained, single-aliquot regenerative-dose (SAR) technique. The obtained optical ages are mostly consistent with other assessments (radiocarbon, tephrochronology) and stratigraphic constraints. OSL allows for the dating to 56–43 ka of an asymmetric subsidence stage that forced alluvial fan progradation, filling of a former lacustrine area, and development of an axial alluvial plain. A short period of Mediterranean-type pedogenesis, recorded at the top of the prograding-aggrading fans (OSL age bracket 43–32 ka), corresponds with MIS 3. During the subsequent stage of decline of vegetation cover, possibly corresponding to MIS 2, the latest progradation of alluvial fans occurred. The subsequent uplift and breakthrough of the basin threshold during the latest Pleistocene and Holocene induced entrenchment of the drainage network. The results presented here provide an example of the usefulness of OSL dating in intermontane continental settings where other geochronological constraints are scarce.

scholarly journals Alluvial Fan Database: Presenting Geographical Information Using an Internet Map Server.

2000 ◽  
Vol 109 (1) ◽  
pp. 120-125
Author(s):  
Takashi OGUCHI ◽  
Kyoji SAITO ◽  
Midori HARA ◽  
Hiroshi KADOMURA ◽  
Zhou LIN
Keyword(s):  
Alluvial Fan ◽  
Geographical Information

scholarly journals Investigation of Soil Characterization in Hatay Province in Turkey by Using Seismic Refraction, Multichannel Analysis of Surface Waves and Microtremor

2021 ◽  
Vol 24 (4) ◽  
pp. 473-484
Author(s):  
Cengiz Kurtuluş ◽  
Ibrahim Sertcelik ◽  
Fadime Sertçelik ◽  
Hamdullah Livaoğlu ◽  
Cüneyt Şaş
Keyword(s):  
Surface Waves ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Seismic Refraction ◽  
Strong Motion ◽  
Site Classification ◽  
Eurocode 8 ◽  
Site Class ◽  
Multichannel Analysis

In this study, shallow seismic surveys, including seismic refraction, Multichannel Analysis of Surface Waves (MASW), Refraction Microtremor (ReMi), and Microtremor measurements were conducted to estimate site characterization at 26 strong-motion stations of AFAD (Disaster and Emergency Management Presidency) in the province of Hatay, situated in one of the most seismically active regions in southern Turkey. The Horizontal to vertical spectral ratio (HVSR) technique was applied, using smoothed Fourier spectra derived from a long duration series to determine dominant frequency values at different amplification levels. Shear wave velocity up to 30 m of the ground was detected with MASW analysis. In the ReMi analysis, up to 80 m was reached with a corresponding average of 650 m/s shear wave velocity. The shear wave velocities estimated by the MASW method up to 30 m were compared with those found by the ReMi method, and they were observed to be very compatible. The province of Hatay was classified according to Vs30 based NEHRP Provisions, Eurocode-8, the Turkish Building Earthquake Regulation (TBDY-2018), and Rodriguez-Marek et al. (2001). The shear-wave velocity (Vs30), Horizontal to Vertical ratio’s (H/V) peak amplitude, dominant period, and site class of each site were determined. The H/V peak amplitudes range between 1.9 and 7.6, while the predominant periods vary from 0.23 sec to 2.94sec in the study area. These results are investigated to explain the consistency of site classification schemes.

scholarly journals Brief Communication: A case study of risk assessment for facilities associated with earthquake-induced liquefaction potential in Kimhae City, South Korea 

2021 ◽  
Author(s):  
Sang-Soo Jeon ◽  
Daeyang Heo ◽  
Sang-Seung Lee
Keyword(s):  
Geographical Information Systems ◽  
Standard Penetration Test ◽  
Geographical Information ◽  
Liquefaction Potential ◽  
Risk Levels ◽  
Potential Index ◽  
Secondary Damage ◽  
Yangsan Fault ◽  
The Nakdong River ◽  
High Level

Abstract. Liquefaction causes secondary damage after earthquakes; however, liquefaction related phenomena were rarely reported until after the Mw = 5.4 November 15, 2017 Pohang earthquake in Korea. Both the Mw = 5.8 September 12, 2016 Gyeongju earthquake and Mw = 5.4 November 15, 2017 Pohang earthquake occurred in the fault zone of Yangsan City (located in the south-eastern part of Korea), and both of these earthquakes induced liquefaction. Moreover, they demonstrated that Korea is not safe against the liquefaction induced by earthquakes. In this study, estimations and calculations were performed based on the distances between the centroids of administrative districts and an epicenter located at the Yangsan Fault, the peak ground accelerations (PGAs) induced by Mw = 5.0 and 6.5 earthquakes, and a liquefaction potential index (LPI) calculated based on groundwater level and standard penetration test results from 274 locations in Kimhae City (adjacent to the Nakdong river and across the Yangsan Fault). Then, a kriging method using geographical information systems was used to evaluate the liquefaction effects on the risk levels of facilities. The results indicate that a Mw = 5.0 earthquake induces a small and low level of liquefaction, resulting in slight risk for facilities, but a Mw = 6.5 earthquake induces a large and high level of liquefaction, resulting in a severe risk for facilities.

scholarly journals ANALYSIS OF LAND USE CHANGES AND THEIR INFLUENCE ON SOIL FEATURES. CASE STUDY: SECAȘ VILLAGE, TIMIȘ COUNTY (ROMANIA)

2019 ◽  
Vol 13 (2) ◽  
pp. 157-166
Author(s):  
Loredana Copăcean ◽  
Ionut Zisu ◽  
Valentina Mazăre ◽  
Luminiţa Cojocariu
Keyword(s):  
Land Use ◽  
Rural Communities ◽  
Geographical Information Systems ◽  
Agricultural Land ◽  
Scientific Information ◽  
Land Use Changes ◽  
Arable Land ◽  
Geographical Information ◽  
Soil Features ◽  
The North

The soil, regarded as a natural resource, but also as a determinant element of the living standards of rural communities, manly agricultural, may be influenced, directly and indirectly, by the modality of land organizing and use. Starting from this consideration, through this study, the spatial and temporal evolution of land use is being pursued, particularly that of forest areas and wooded grasslands. The goal is to notice the changes that have occurred over a 30-year period and the manner how these changes are reflected on the soil features. The researches presented in this paper have been taking place in the north-eastern hilly area of Timiş County, that area having entirely a rural character. For realizing this study satellite images, topographical and cadastral maps, from different time periods, national and international databases, data from specialty literature were used. To all these we should add direct observations in the field, topographic surveys and information collected from local authorities. The processing of cartographic materials and data and scientific information has been realized with Geographical Information Systems specific applications. The obtained result has been expressed in the form of thematic maps, in graphic form or as statistical analysis. At the level of the analyzed area, the obvious changes in the land use, registered over time, are caused by a number of factors, such as: the organization form, from communist to capitalist policies, leaving agricultural land as fallow ground, reduction in livestock, changing land use etc. All these changes have caused the extension of the wooded grasslands, reduction of arable land, installing inferior forest vegetation in qualitative and quantitative terms etc. As a result, the soil, one of the most important natural resources, is degraded qualitatively, underexploited, and on the other hand, its role as a direct and indirect food producer for local communities is significantly reduced.

PRELIMINARY NEHRP SITE CLASSIFICATION AND SOIL AMPLIFICATION MAP OF OKLAHOMA

2017 ◽  
Author(s):  
Jefferson C. Chang ◽  
◽  
Brittany N. Pritchett ◽  
Brittany N. Pritchett ◽  
Julie M. Chang ◽  
...  
Keyword(s):  
Site Classification ◽  
Soil Amplification
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