scholarly journals A remote-sensing-based intensity–duration threshold, Faifa Mountains, Saudi Arabia

2019 ◽  
Vol 19 (6) ◽  
pp. 1235-1249 ◽  
Author(s):  
Sita Karki ◽  
Mohamed Sultan ◽  
Saleh Alsefry ◽  
Hassan Alharbi ◽  
Mustafa Kemal Emil ◽  
...  
Keyword(s):  
Field Data ◽  
Mass Movement ◽  
Google Earth ◽  
Archival Data ◽  
Backscatter Coefficient ◽  
Duration Threshold ◽  
Radar Imagery ◽  
Temporal And Spatial ◽  
Precipitation Events ◽  
Red Sea Hills

Abstract. Construction of intensity–duration (ID) thresholds and early-warning and nowcasting systems for landslides (EWNSLs) are hampered by the paucity of temporal and spatial archival data. This work represents significant steps towards the development of a prototype EWNSL to forecast and nowcast landslides over the Faifa Mountains in the Red Sea Hills. The developed methodologies rely on readily available, temporal, archival Google Earth and Sentinel-1A imagery, precipitation measurements, and limited field data to construct an ID threshold for Faifa. The adopted procedures entail the generation of an ID threshold to identify the intensity and duration of precipitation events that cause landslides in the Faifa Mountains, and the generation of pixel-based ID curves to identify locations where movement is likely to occur. Spectral and morphologic variations in temporal Google Earth imagery following precipitation events were used to identify landslide-producing storms and generate the Faifa ID threshold (I =4.89D−0.65). Backscatter coefficient variations in radar imagery were used to generate pixel-based ID curves and identify locations where mass movement is likely to occur following landslide-producing storms. These methodologies accurately distinguished landslide-producing storms from non-landslide-producing ones and identified the locations of these landslides with an accuracy of 60 %.

scholarly journals A Remote Sensing–based Intensity-Duration Curve, Faifa Mountains, Saudi Arabia

2018 ◽  
Author(s):  
Sita Karki ◽  
Mohamed Sultan ◽  
Saleh A. Al-Sefry ◽  
Hassan M. Alharbi ◽  
Mustafa Kemal Emil ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Saudi Arabia ◽  
Early Warning ◽  
Field Data ◽  
Early Warning Systems ◽  
Google Earth ◽  
Archival Data ◽  
Warning Systems ◽  
Temporal And Spatial ◽  
Red Sea Hills

Abstract. Construction of intensity-duration (ID) curves and early warning systems for landslides (EWSL) are hampered by the paucity of temporal and spatial archival data. We developed methodologies that could be used for the construction of an ID curve that could be used for the construction of an EWSL over the Faifa Mountains in the Red Sea Hills. The developed methodologies relies on temporal, readily available, archival Google Earth and Sentinel-1 imagery, precipitation measurements, and limited field data. These methodologies accurately distinguished landslide-producing storms from non–landslide producing ones and identified the locations of these landslides with an accuracy of 60 %.

scholarly journals Identificação de Cicatrizes de Movimentos de Massa na Borda Oriental da Bacia do Paraná com base em Imagens Landsat 5-TM (Identification of Landslides Scars in the Eastern Edge of the Paraná Basin)

2015 ◽  
Vol 8 (1) ◽  
pp. 056
Author(s):  
Mariana Madruga De Brito
Keyword(s):  
Image Processing ◽  
Mass Movement ◽  
Google Earth ◽  
Economic Losses ◽  
Mass Movements ◽  
Tm Image ◽  
Paraná Basin ◽  
Landsat 5 Tm ◽  
Parana Basin ◽  
Eastern Edge

Movimentos de massa são fenômenos naturais caracterizados pelo deslocamento de solo e rocha vertente abaixo. Quando esses processos ocorrem em áreas urbanizadas, podem causar perdas econômicas, impactos sociais e, em casos extremos, perda de vidas humanas. Na tentativa de mitigar tais desastres, torna-se necessário mapear os locais já afetados pelos mesmos, uma vez que escorregamentos recentes podem sugerir futuros padrões de instabilidade. Nesse sentido, este trabalho teve por objetivo mapear as cicatrizes de movimentos de massa em um segmento da Borda Oriental da Bacia do Paraná, por meio do processamento de uma imagem Landsat 5-TM, órbita/ponto 220/80, data de passagem 28/08/2009. Para facilitar a discriminação destas feições, elaboraram-se composições coloridas RGB e processamentos tais como Ampliação Linear de Contraste (ALC), razão entre bandas e Análise por Componentes Principais (PCA). A fim de validar o inventário elaborado, utilizaram-se imagens de alta resolução disponíveis no software Google Earth®. Ao total, foram identificadas 63 cicatrizes com a imagem Landsat 5-TM e 121 cicatrizes com as imagens do Google Earth®. Os principais tipos de movimentos de massa mapeados são escorregamentos translacionais rasos e corrida de detritos. A identificação das cicatrizes foi possível devido às diferenças de tonalidade, cor, matiz e textura nas imagens orbitais após a ocorrência desses processos. Os resultados obtidos representam um passo inicial para a análise da suscetibilidade da área.     A B S T R A C T Mass movements are natural phenomena characterized by the downslope movement of soil and rock. When these processes occur in urban areas they can cause economic losses, social impacts and, in extreme cases, loss of human lives. In an attempt to mitigate such disasters, it is necessary to map sites affected by them, since recent landslides may suggest future patterns of instability. In this sense, this study aimed to map the mass movement scars in a segment of the Eastern Edge of the Paraná Basin, through the processing of a Landsat 5-TM image, 220/80 orbit-point and date of passage 08/28/2009. To facilitate the recognition of these features, RGB color compositions and image processing techniques such as contrast stretching, ratio between bands and Principal Component Analysis (PCA) were applied. In order to validate the inventory, high-resolution images available at Google Earth® software were used. Totally, 63 scars were identified with the Landsat 5-TM image and 121 with Google Earth® images. The main types of mass movements mapped are translational landslides and debris flows. The identification of the scars was possible due to differences in tone, color, hue and texture at the orbital images after the occurrence of such processes. Results obtained represent an initial step towards the susceptibility analysis of the area. Keywords: Landslide inventory; Digital image processing; Satellite images; Geoprocessing.  

scholarly journals Flood Prevention and Emergency Response System Powered by Google Earth Engine

2018 ◽  
Vol 10 (8) ◽  
pp. 1283 ◽  
Author(s):  
Cheng-Chien Liu ◽  
Ming-Chang Shieh ◽  
Ming-Syun Ke ◽  
Kung-Hwa Wang
Keyword(s):  
Emergency Response ◽  
Google Earth ◽  
River Channels ◽  
Time Data ◽  
Flood Prevention ◽  
Emergency Response System ◽  
Response System ◽  
Radar Imagery ◽  
Google Earth Engine ◽  
Inundation Map

This paper reviews the efforts made and experiences gained in developing the Flood Prevention and Emergency Response System (FPERS) powered by Google Earth Engine, focusing on its applications at the three stages of floods. At the post-flood stage, FPERS integrates various remote sensing imageries, including Formosat-2 optical imagery to detect and monitor barrier lakes, synthetic aperture radar imagery to derive an inundation map, and high-spatial-resolution photographs taken by unmanned aerial vehicles to evaluate damage to river channels and structures. At the pre-flood stage, a huge amount of geospatial data are integrated in FPERS and are categorized as typhoon forecast and archive, disaster prevention and warning, disaster events and analysis, or basic data and layers. At the during-flood stage, three strategies are implemented to facilitate the access of the real-time data: presenting the key information, making a sound recommendation, and supporting the decision-making. The example of Typhoon Soudelor in August of 2015 is used to demonstrate how FPERS was employed to support the work of flood prevention and emergency response from 2013 to 2016. The capability of switching among different topographic models and the flexibility of managing and searching data through a geospatial database are also explained, and suggestions are made for future works.

scholarly journals Oceanic protists with different forms of acquired phototrophy display contrasting biogeographies and abundance

2017 ◽  
Vol 284 (1860) ◽  
pp. 20170664 ◽  
Author(s):  
S. G. Leles ◽  
A. Mitra ◽  
K. J. Flynn ◽  
D. K. Stoecker ◽  
P. J. Hansen ◽  
...  
Keyword(s):  
Field Data ◽  
Distribution Patterns ◽  
Comprehensive Analysis ◽  
High Biomass ◽  
Marine Research ◽  
Marine Food Web ◽  
Temporal And Spatial Patterns ◽  
Functional Types ◽  
Marine Food ◽  
Temporal And Spatial

This first comprehensive analysis of the global biogeography of marine protistan plankton with acquired phototrophy shows these mixotrophic organisms to be ubiquitous and abundant; however, their biogeography differs markedly between different functional groups. These mixotrophs, lacking a constitutive capacity for photosynthesis (i.e. non-constitutive mixotrophs, NCMs), acquire their phototrophic potential through either integration of prey-plastids or through endosymbiotic associations with photosynthetic microbes. Analysis of field data reveals that 40–60% of plankton traditionally labelled as (non-phototrophic) microzooplankton are actually NCMs, employing acquired phototrophy in addition to phagotrophy. Specialist NCMs acquire chloroplasts or endosymbionts from specific prey, while generalist NCMs obtain chloroplasts from a variety of prey. These contrasting functional types of NCMs exhibit distinct seasonal and spatial global distribution patterns. Mixotrophs reliant on ‘stolen’ chloroplasts, controlled by prey diversity and abundance, dominate in high-biomass areas. Mixotrophs harbouring intact symbionts are present in all waters and dominate particularly in oligotrophic open ocean systems. The contrasting temporal and spatial patterns of distribution of different mixotroph functional types across the oceanic provinces, as revealed in this study, challenges traditional interpretations of marine food web structures. Mixotrophs with acquired phototrophy (NCMs) warrant greater recognition in marine research.

The sum of its parts? Sources of local legitimacy

2016 ◽  
Vol 51 (4) ◽  
pp. 522-538 ◽  
Author(s):  
Birte J Gippert
Keyword(s):  
Field Data ◽  
Local Behaviour ◽  
Effective Functioning ◽  
International Operations ◽  
Local Actors ◽  
Temporal And Spatial ◽  
International Peacebuilding ◽  
The Eu

The article analyses the sources of local actors’ legitimacy perceptions towards international peacebuilding operations. Local legitimacy perceptions are increasingly recognised as shaping local behaviour towards international peacebuilding, which influences the effective functioning of the operation. Legitimacy debates in peacebuilding are either absent or imported from the literature on domestic legitimacy, without respect to the specific temporal and spatial situation of international operations. The article first explores which legitimacy sources influence local legitimacy perceptions of international peacebuilding operations. It finds that two sources are relevant: output and procedure. Second, it investigates how exactly legitimacy arises from them. In doing so, it demonstrates that output and procedure are umbrella terms comprising several sub-elements which influence legitimacy in different, sometimes contradictory, ways. Finally, the article empirically explores which of the sources are important to local actors’ legitimacy perceptions using field data from the EU peacebuilding operations EULEX in Kosovo and EUPM Bosnia-Herzegovina.

scholarly journals A note on a Comparison of Starting Points for the Generation of D-optimal Second-order Designs

2020 ◽  
Vol 7 (2) ◽  
pp. 1001-1008
Author(s):  
Ngozi Chizoma Umelo-Ibemere
Keyword(s):  
Climate Change ◽  
Mathematical Analysis ◽  
Field Data ◽  
Satellite Images ◽  
Cultivated Land ◽  
Temporal And Spatial ◽  
Land Surfaces ◽  
Optical Satellite Images ◽  
Agricultural Areas ◽  
Sentinel 2

Agricultural monitoring has become an absolute necessity in the Sahel countries, especially with climate change which constitutes a real threat for this sector. The aim of this work is to develop a methodology for identifying crops and mapping agricultural areas using Sentinel-2 data from the Copernicus program. The purpose of this work consisted in discriminating the crops of millet, maize and peanuts. This is to analyse the scientific and technical obstacles related to this problem. For this, we have made a mathematical analysis of optical satellite images. High temporal and spatial resolution images (10m to 60m) of Sentinel 2 sensors were used in this work. This unique set of data coupled with field data, has permitted to carry out a diagnosis of land cover and cultivated land surfaces, and evaluating the contribution of this type of data for crop forecast

scholarly journals Study on the Causes of Inaccuracy of Qibla Direction of the Great Mosque Baitul Makmur West Aceh

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Riza Afrian Mustaqim ◽  
Reza Akbar
Keyword(s):  
Field Data ◽  
Legal Status ◽  
Descriptive Analysis ◽  
Field Research ◽  
Google Earth ◽  
Earth Observation ◽  
Minor Role ◽  
Interview Techniques ◽  
Analysis Technique

The accuracy of the Qibla direction at the Baitul Makmur Great Mosque in West Aceh cannot tolerate. The reason is that the value of deviation is so high that it does not face ainul ka'bah or even jihatul ka'bah. This Qiblah direction is not by the minimum limit of tolerance for the variation of the Qibla direction and is not by the Islamic legal status. This study examines the causes of the inaccuracy of the Qibla of the Great Mosque of Baitul Makmur Meulaboh West Aceh, namely the lack of role of figures and efforts to maintain the architecture of the mosque building. This research belongs to qualitative field research, by verifying the direction of the Qiblah with the rashdul qibla method and google earth observation to explore causes of inaccuracy. Interview techniques are also used to obtain in-depth field data. The analysis technique used is descriptive analysis. This study indicates that the inaccuracy of the Qibla direction of the Baitul Makmur Great Mosque in West Aceh is inseparable from the minor role of religious figures and leaders at the beginning of the Mosque's construction. Until now, the direction of the Mosque's Qiblah is still parallel to the mihrab. Renovations were also not carried out because of maintaining the architecture of the mosque building. Renovation of the mosque building to calibrate the Qibla direction would reduce the aesthetics of the mosque building.

scholarly journals Drought Effects on Forests and Rangelands in the US Caribbean

2016 ◽  
Keyword(s):  
Puerto Rico ◽  
Climate Models ◽  
Virgin Islands ◽  
Severe Drought ◽  
Temporal And Spatial Distribution ◽  
The Third ◽  
The Us ◽  
Temporal And Spatial ◽  
The U.S ◽  
Precipitation Events

Issues of water quality and scarcity are of great concern across the U.S. Caribbean. In recent years Puerto Rico and the U.S. Virgin Islands have experienced uncommonly dry weather that has caused moderate to severe droughts. In 2014-2015, severe drought in Puerto Rico required the implementation of water restrictions that affected millions of people. The summer of 2015 was the third driest period in Puerto Rico since 1898, forcing the strictest water rationing in its history. Emerging climate models for the region (Figure 1) predict an overall decrease in precipitation over the next century, but also to greater variance in seasonality and an increase in intense precipitation events. The temporal and spatial distribution of rainfall can have profound effects on the hydrology as well as the phenology and life-cycle of trees, rangeland species, pests and pollinators. Changing rainfall patterns will mean major adjustments in how working lands are managed by producers and planners.

scholarly journals Natural Afforestation on Abandoned Agricultural Lands during Post-Soviet Period: A Comparative Landsat Data Analysis of Bordering Regions in Russia and Belarus

2022 ◽  
Vol 14 (2) ◽  
pp. 322
Author(s):  
Dmitry V. Ershov ◽  
Egor A. Gavrilyuk ◽  
Natalia V. Koroleva ◽  
Elena I. Belova ◽  
Elena V. Tikhonova ◽  
...  
Keyword(s):  
Time Series ◽  
Field Data ◽  
Forest Cover ◽  
Arable Land ◽  
Google Earth ◽  
Soviet Period ◽  
Ecosystem Functions ◽  
Landsat Data ◽  
Agricultural Lands ◽  
Post Soviet Period

Remote monitoring of natural afforestation processes on abandoned agricultural lands is crucial for assessments and predictions of forest cover dynamics, biodiversity, ecosystem functions and services. In this work, we built on the general approach of combining satellite and field data for forest mapping and developed a simple and robust method for afforestation dynamics assessment. This method is based on Landsat imagery and index-based thresholding and specifically targets suitability for limited field data. We demonstrated method’s details and performance by conducting a case study for two bordering districts of Rudnya (Smolensk region, Russia) and Liozno (Vitebsk region, Belarus). This study area was selected because of the striking differences in the development of the agrarian sectors of these countries during the post-Soviet period (1991-present day). We used Landsat data to generate a consistent time series of five-year cloud-free multispectral composite images for the 1985–2020 period via the Google Earth Engine. Three spectral indices, each specifically designed for either forest, water or bare soil identification, were used for forest cover and arable land mapping. Threshold values for indices classification were both determined and verified based on field data and additional samples obtained by visual interpretation of very high-resolution satellite imagery. The developed approach was applied over the full Landsat time series to quantify 35-year afforestation dynamics over the study area. About 32% of initial arable lands and grasslands in the Russian district were afforested by the end of considered period, while the agricultural lands in Belarus’ district decreased only by around 5%. Obtained results are in the good agreement with the previous studies dedicated to the agricultural lands abandonment in the Eastern Europe region. The proposed method could be further developed into a general universally applicable technique for forest cover mapping in different growing conditions at local and regional spatial levels.

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