scholarly journals PEMANTAUAN SEBARAN ABU VULKANIK MENGGUNAKAN PENGINDERAAN JAUH SATELIT HIMAWARI-8 DAN AURA/OMI (OZONE MAPPING INSTRUMENT)

2017 ◽  
Vol 19 (1) ◽  
pp. 33
Author(s):  
Fatkhuroyan Fatkhuroyan ◽  
Trinah Wati
Keyword(s):  
Remote Sensing ◽  
Volcanic Ash ◽  
Satellite Image ◽  
Volcanic Eruptions ◽  
Hazardous Substances ◽  
High Temporal Resolution ◽  
Volcanic Zone ◽  
Gas Emissions ◽  
Red Color ◽  
Color Composite

<p class="JudulABSInd"><strong>                                                                                  ABSTRAK</strong></p><p class="abstrak">Indonesia mempunyai jalur gunung api mulai dari Sumatera, Jawa, Bali, Nusa Tenggara, Sulawesi, Banda, Maluku hingga Papua (USGS,1999). Hal ini menyebabkan Indonesia rawan terjadinya bencana akibat erupsi gunung berapi seperti lahar, abu vulkanik serta pencemaran udara yang mengandung zat berbahaya seperti sulfur dioksida (SO<sub>2</sub>) dan hidrogen sulfida (H<sub>2</sub>S). Sebaran abu vulkanik letusan gunung berapi menimbulkan banyak kerugian di sektor pertanian, kesehatan dan juga penerbangan. Pemantauan sebaran abu vulkanik menggunakan analisis penginderaan jauh satelit Himawari-8 dan AURA/OMI dilakukan pada peristiwa erupsi Gunung Raung, Gamalama dan Rinjani pada tahun 2015 bertujuan untuk mendeteksi dan memantau abu vulkanik gunung berapi serta arah pergerakannya dan dikaitkan dengan aktivitas gunung tersebut. Analisis menggunakan teknik komposit warna RGB (<em>Red Green Blue</em>) pada beberapa kanal visible dan inframerah dengan perangkat lunak Sataid pada citra satelit Himawari-8, sedangkan pada citra satelit AURA/OMI dengan pendeteksian emisi gas SO<sub>2</sub>. Hasil Pantauan satelit Himawari-8 menunjukkan abu vulkanik hasil kombinasi RGB dapat dideteksi dengan visual warna merah terang, sedangkan dari satelit OMI berdasarkan emisi SO<sub>2</sub> dapat digunakan untuk melacak keberadaan abu vulkanik dan berkaitan dengan aktivitas gunung. Pemantauan menggunakan penginderaan jauh dengan resolusi temporal yang cukup tinggi pada satelit Himawari-8 (10 menit) dan OMI (harian) dapat digunakan untuk melacak keberadaan abu vulkanik dan arah sebaran yang bermanfaat untuk antisipasi bahaya dari abu vulkanik tersebut sehingga dapat dimanfaatkan untuk penyelamatan kebencanaan.</p><p><strong>Kata kunci: </strong>Abu Vulkanik, Himawari-8, OMI, penginderaan jauh</p><p class="judulABS"><em><strong>                                                                                   ABSTRACT</strong></em></p><p class="Abstrakeng"><em>Indonesia volcanic zone lanes sweep through along Sumatera, Java, Bali, Nusa Tenggara, Sulawesi, Banda, Molucca to Papua (USGS, 1999). It caused Indonesia become very vulnerable to disaster due to material from volcanic eruptions such as lava, volcanic ash and air pollution containing hazardous substances such as sulfur dioxide (SO<sub>2</sub>) and hydrogen sulfide (H<sub>2</sub>S). The distribution of Volcanic Ash due to volcanic eruption has caused many losses in the agricultural, health and aviation sectors. In this study, we observed the spread of volcanic ash using remote sensing analysis of satellite Himawari-8 and AURA / OMI at eruptions of Mount Raung, Gamalama and Rinjani in 2015. The aims are to detect and to monitor the volcanic ash as well as the direction of its movement that were associated to the mountain's activities. The analysis used the technique of color composite RGB (Red Green Blue) on several visible and infrared channels using Sataid software on satellite images Himawari-8 and SO<sub>2</sub> gas emissions detection on satellite image AURA / OMI. The result of RGB combination from Himawari-8 showed light red color for volcanic ash visualization, while SO<sub>2</sub> gas emissions from OMI can be use to track the vulcanic ash. The analysis showed that remote sensing with high temporal resolution of Himawari-8 (every 10 minutes) and OMI (daily) can be used to track the presence of volcanic ash and its direction of distribution and very useful to anticipate the hazards and for disaster rescue.</em></p><p><strong><em>Keywords: </em></strong><em>Volcanic Ash, Himawari-8, OMI, remote sensing</em></p>

scholarly journals Optical, microphysical and compositional properties of the Eyjafjallajökull volcanic ash

2014 ◽  
Vol 14 (19) ◽  
pp. 10649-10661 ◽  
Author(s):  
A. Rocha-Lima ◽  
J. V. Martins ◽  
L. A. Remer ◽  
N. A. Krotkov ◽  
M. H. Tabacniks ◽  
...  
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Refractive Index ◽  
Optical Properties ◽  
Elemental Composition ◽  
Wavelength Range ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Mixed Modes

Abstract. Better characterization of the optical properties of aerosol particles are an essential step to improve atmospheric models and satellite remote sensing, reduce uncertainties in predicting particulate transport, and estimate aerosol forcing and climate change. Even natural aerosols such as mineral dust or particles from volcanic eruptions require better characterization in order to define the background conditions from which anthropogenic perturbations emerge. We present a detailed laboratorial study where the spectral optical properties of the ash from the April–May (2010) Eyjafjallajökull volcanic eruption were derived over a broad spectral range, from ultra-violet (UV) to near-infrared (NIR) wavelengths. Samples of the volcanic ash taken on the ground in the vicinity of the volcano were sieved, re-suspended, and collected on filters to separate particle sizes into fine and mixed (coarse and fine) modes. We derived the spectral mass absorption efficiency αabs [m2g−1] for fine and mixed modes particles in the wavelength range from 300 to 2500 nm from measurements of optical reflectance. We retrieved the imaginary part of the complex refractive index Im(m) from αabs, using Mie–Lorenz and T-matrix theories and considering the size distribution of particles obtained by scanning electron microscopy (SEM), and the grain density of the volcanic ash measured as ρ = 2.16 ± 0.13 g cm−3. Im(m) was found to vary from 0.001 to 0.005 in the measured wavelength range. The dependence of the retrieval on the shape considered for the particles were found to be small and within the uncertainties estimated in our calculation. Fine and mixed modes were also analyzed by X-ray fluorescence, exhibiting distinct elemental composition supporting the optical differences we found between the modes. This is a comprehensive and consistent characterization of spectral absorption and imaginary refractive index, density, size, shape and elemental composition of volcanic ash, which will help constrain assumptions of ash particles in models and remote sensing, thereby narrowing uncertainties in representing these particles both for short-term regional forecasts and long-term climate change.

scholarly journals Evaluating Changes in Land Use Land Cover using Remote Sensing Satellite Data and GIS (A Case Study in Patna Municipal Corporation Area) Patna, Bihar

2020 ◽  
pp. 346-353
Author(s):  
Mohammad Ahmad ◽  
Nikhat Hassan Munim
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Land Cover ◽  
Satellite Image ◽  
Land Use Land Cover ◽  
Rural And Urban ◽  
Multi Temporal ◽  
Color Composite ◽  
Irs P6 Liss Iv

Evaluation of land use land cover (LULC) change is an essential aspect of development in rural and urban sectors. This paper investigates the changes in LULC aspects of an environmentally vulnerable Patna Municipal Corporation (PMC) area in the middle-Ganga Plain, India. We offer Remote Sensing (RS), and Geographic Information System (GIS) techniques delineated LULC types include water bodies, agriculture land, fallow land, wasteland, built-up land and vegetation of the study area. LULC mapping of the study area was done through False Color Composite (FCC) Satellite image Resourcesat-1 (IRS P6 LISS-IV) and Resourcesat 2A (IRS-R2A LISS-IV) with 5.8-meter spatial resolution data of the year 2007 and 2018 respectively. The supervised classification and maximum likelihood equation were used to classified two multi-temporal images. Then temporal changes were detected by comparison between two LULC classified maps of 2007 and 2018, which was produced independently. Patna Municipal Corporation (PMC) area, Patna is one of the environmentally vulnerable areas under the threat of environmental and ecological degradation as a result of human activities due to improper land cover management. The main objective of using change detection is an important technique to detect changes in LULC over time in PMC, Patna between 2007-2018, and it is significant for updating land cover or natural resource management. The interpretation of this study has substantial changes in LULC occurred in the Patna Municipal Corporation (PMC) area, Patna within the period 2007-2018, related to urbanisation and economic development. The analysis outcome indicates the most remarkable changes occurred an increase in Built-up, (+) 21.86 % between 2007-2018, whereas the area of cropland and vegetation decreased (-) 8.95 % and (-) 5.8% respectively between 2007-2018. In the spatial distribution pattern, other changes have also occurred. This study will give the benefit in future action plans in land use and urban development and avoid LULC changes without proper planning. It will be most significant for the natural environment.

Random Forest (RF) and Artificial Neural Network (ANN) Algorithms for LULC Mapping

2020 ◽  
Vol 38 (4A) ◽  
pp. 510-514
Author(s):  
Tay H. Shihab ◽  
Amjed N. Al-Hameedawi ◽  
Ammar M. Hamza
Keyword(s):  
Neural Network ◽  
Remote Sensing ◽  
Artificial Neural Network ◽  
Random Forest ◽  
Satellite Image ◽  
Landsat 8 ◽  
Optical Remote Sensing ◽  
Data Set ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

In this paper to make use of complementary potential in the mapping of LULC spatial data is acquired from LandSat 8 OLI sensor images are taken in 2019.  They have been rectified, enhanced and then classified according to Random forest (RF) and artificial neural network (ANN) methods. Optical remote sensing images have been used to get information on the status of LULC classification, and extraction details. The classification of both satellite image types is used to extract features and to analyse LULC of the study area. The results of the classification showed that the artificial neural network method outperforms the random forest method. The required image processing has been made for Optical Remote Sensing Data to be used in LULC mapping, include the geometric correction, Image Enhancements, The overall accuracy when using the ANN methods 0.91 and the kappa accuracy was found 0.89 for the training data set. While the overall accuracy and the kappa accuracy of the test dataset were found 0.89 and 0.87 respectively.

scholarly journals The fate of volcanic ash: premature or delayed sedimentation?

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eduardo Rossi ◽  
Gholamhossein Bagheri ◽  
Frances Beckett ◽  
Costanza Bonadonna
Keyword(s):  
Residence Time ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Theoretical Description ◽  
Particle Sedimentation ◽  
Weather Modeling ◽  
Explosive Volcanic Eruptions ◽  
Travel Distances ◽  
Ash Dispersal

AbstractA large amount of volcanic ash produced during explosive volcanic eruptions has been found to sediment as aggregates of various types that typically reduce the associated residence time in the atmosphere (i.e., premature sedimentation). Nonetheless, speculations exist in the literature that aggregation has the potential to also delay particle sedimentation (rafting effect) even though it has been considered unlikely so far. Here, we present the first theoretical description of rafting that demonstrates how delayed sedimentation may not only occur but is probably more common than previously thought. The fate of volcanic ash is here quantified for all kind of observed aggregates. As an application to the case study of the 2010 eruption of Eyjafjallajökull volcano (Iceland), we also show how rafting can theoretically increase the travel distances of particles between 138–710 μm. These findings have fundamental implications for hazard assessment of volcanic ash dispersal as well as for weather modeling.

scholarly journals Near-real-time volcanic cloud monitoring: insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
S. Engwell ◽  
L. Mastin ◽  
A. Tupper ◽  
J. Kibler ◽  
P. Acethorp ◽  
...  
Keyword(s):  
Real Time ◽  
Volcanic Activity ◽  
Volcanic Ash ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Volcanic Hazards ◽  
Process Data ◽  
Cloud Monitoring ◽  
Satellite Sensors ◽  
Volcanic Cloud

AbstractUnderstanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

More accurate less meaningful? A critical physical geographer’s reflection on interpreting remote sensing land-use analyses

2021 ◽  
pp. 030913332199181
Author(s):  
Andreas Christian Braun
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Geographic Information Systems ◽  
Image Classification ◽  
Satellite Image ◽  
Physical Geography ◽  
Data Availability ◽  
Scientific Results ◽  
Normative Considerations

Land-use and land-cover analyses based on satellite image classification are used in most, if not all, sub-disciplines of physical geography. Data availability and increasingly simple image classification techniques – nowadays, even implemented in simple geographic information systems – increase the use of such analyses. To assess the quality of such land-use analyses, accuracy metrics are applied. The results are considered to have sufficient quality, exceeding thresholds published in the literature. A typical practice in many studies is to confuse accuracy in remote sensing with quality, as required by physical geography. However, notions such as quality are subject to normative considerations and performative practices, which differ between scientific domains. Recent calls for critical physical geography have stressed that scientific results cannot be understood separately from the values and practices underlying them. This article critically discusses the specific understanding of quality in remote sensing, outlining norms and practices shaping it and their relation to physical geography. It points out that, as a seeming paradox, results considered more accurate in remote sensing terms can be less informative – or meaningful – in geographical terms. Finally, a roadmap of how to apply remote sensing land-use analyses more constructively in physical geography is proposed.

scholarly journals A Computational Methodology for the Calibration of Tephra Transport Nowcasting at Sakurajima Volcano, Japan

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 104
Author(s):  
Alexandros P. Poulidis ◽  
Atsushi Shimizu ◽  
Haruhisa Nakamichi ◽  
Masato Iguchi
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Remote Sensing Data ◽  
Volcanic Eruptions ◽  
Weather Research And Forecasting ◽  
Sakurajima Volcano ◽  
Observation Network ◽  
Complementary Strategy ◽  
Physical Quantities ◽  
Do So

Ground-based remote sensing equipment have the potential to be used for the nowcasting of the tephra hazard from volcanic eruptions. To do so raw data from the equipment first need to be accurately transformed to tephra-related physical quantities. In order to establish these relations for Sakurajima volcano, Japan, we propose a methodology based on high-resolution simulations. An eruption that occurred at Sakurajima on 16 July 2018 is used as the basis of a pilot study. The westwards dispersal of the tephra cloud was ideal for the observation network that has been installed near the volcano. In total, the plume and subsequent tephra cloud were recorded by 2 XMP radars, 1 lidar and 3 optical disdrometers, providing insight on all phases of the eruption, from plume generation to tephra transport away from the volcano. The Weather Research and Forecasting (WRF) and FALL3D models were used to reconstruct the transport and deposition patterns. Simulated airborne tephra concentration and accumulated load were linked, respectively, to lidar backscatter intensity and radar reflectivity. Overall, results highlight the possibility of using such a high-resolution modelling-based methodology as a reliable complementary strategy to common approaches for retrieving tephra-related quantities from remote sensing data.

scholarly journals Volcanic Ash, Insecurity for the People but Securing Fertile Soil for the Future

2019 ◽  
Vol 11 (11) ◽  
pp. 3072 ◽  
Author(s):  
Dian Fiantis ◽  
Frisa Ginting ◽  
Gusnidar ◽  
M. Nelson ◽  
Budiman Minasny
Keyword(s):  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Positive Outcome ◽  
Natural Event ◽  
Fertile Soil ◽  
The People ◽  
The World ◽  
The Future ◽  
Security View ◽  
Agricultural Areas

Volcanic eruptions affect land and humans globally. When a volcano erupts, tons of volcanic ash materials are ejected to the atmosphere and deposited on land. The hazard posed by volcanic ash is not limited to the area in proximity to the volcano, but can also affect a vast area. Ashes ejected from volcano’s affect people’s daily life and disrupts agricultural activities and damages crops. However, the positive outcome of this natural event is that it secures fertile soil for the future. This paper examines volcanic ash (tephra) from a soil security view-point, mainly its capability. This paper reviews the positive aspects of volcanic ash, which has a high capability to supply nutrients to plant, and can also sequester a large amount of carbon out of the atmosphere. We report some studies around the world, which evaluated soil organic carbon (SOC) accumulation since volcanic eruptions. The mechanisms of SOC protection in volcanic ash soil include organo-metallic complexes, chemical protection, and physical protection. Two case studies of volcanic ash from Mt. Talang and Sinabung in Sumatra, Indonesia showed the rapid accumulation of SOC through lichens and vascular plants. Volcanic ash plays an important role in the global carbon cycle and ensures soil security in volcanic regions of the world in terms of boosting its capability. However, there is also a human dimension, which does not go well with volcanic ash. Volcanic ash can severely destroy agricultural areas and farmers’ livelihoods. Connectivity and codification needs to ensure farming in the area to take into account of risk and build appropriate adaptation and resilient strategy.

scholarly journals Constructing Damage Indices Based on Publicly Available Spatial Data: Exemplified by Earthquakes and Volcanic Eruptions in Indonesia

2021 ◽  
Author(s):  
Emmanuel Skoufias ◽  
Eric Strobl ◽  
Thomas Tveit
Keyword(s):  
Spatial Data ◽  
Volcanic Ash ◽  
Satellite Images ◽  
Fragility Curves ◽  
Volcanic Eruptions ◽  
Damage Indices ◽  
Damage Indicator ◽  
Time Period ◽  
Peak Ground Motion

AbstractThis article demonstrates the construction of earthquake and volcano damage indices using publicly available remote sensing sources and data on the physical characteristics of events. For earthquakes we use peak ground motion maps in conjunction with building type fragility curves to construct a local damage indicator. For volcanoes we employ volcanic ash data as a proxy for local damages. Both indices are then spatially aggregated by taking local economic exposure into account by assessing nightlight intensity derived from satellite images. We demonstrate the use of these indices with a case study of Indonesia, a country frequently exposed to earthquakes and volcanic eruptions. The results show that the indices capture the areas with the highest damage, and we provide overviews of the modeled aggregated damage for all provinces and districts in Indonesia for the time period 2004 to 2014. The indices were constructed using a combination of software programs—ArcGIS/Python, Matlab, and Stata. We also outline what potential freeware alternatives exist. Finally, for each index we highlight the assumptions and limitations that a potential practitioner needs to be aware of.

Chemical Composition of Ice Containing Tephra Layers in the Byrd Station Ice Core, Antarctica

1988 ◽  
Vol 30 (3) ◽  
pp. 315-330 ◽  
Author(s):  
Julie M. Palais ◽  
Philip R. Kyle
Keyword(s):  
Chemical Composition ◽  
Silicate Glass ◽  
Residence Time ◽  
Volcanic Ash ◽  
Global Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Tephra Layers ◽  
The Antarctic ◽  
Hydrolysis Of

The chemical composition of ice containing tephra (volcanic ash) layers in 22 sections of the Byrd Station ice core was examined to determine if the volcanic eruptions affected the chemical composition of the atmosphere and precipitation in the vicinity of Byrd Station. The liquid conductivity, acidity, sulfate, nitrate, aluminum, and sodium concentrations of ice samples deposited before, during, and after the deposition of the tephra layers were analyzed. Ice samples that contain tephra layers have, on average, about two times more sulfate and three to four times more aluminum than nonvolcanic ice samples. The acidity of ice samples associated with tephra layers is lowered by hydrolysis of silicate glass and minerals. Average nitrate, sodium, and conductivity are the same in all samples. Because much of the sulfur and chlorine originally associated with these eruptions may have been scavenged by ash particles, the atmospheric residence time of these volatiles would have been minimized. Therefore the eruptions probably had only a small effect on the composition of the Antarctic atmosphere and a negligible effect on local or global climate.

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