scholarly journals Remote Monitoring of Ground Motion Hazards in High Mountain Terrain Using InSAR: A Case Study of the Lake Sarez Area, Tajikistan

2021 ◽  
Vol 11 (18) ◽  
pp. 8738
Author(s):  
Stephen Grebby ◽  
Andrew Sowter ◽  
David Gee ◽  
Ahmed Athab ◽  
Betsabé De la Barreda-Bautista ◽  
...  
Keyword(s):  
Ground Motion ◽  
Remote Monitoring ◽  
Land Surface ◽  
Significant Proportion ◽  
High Mountain ◽  
Mountain Areas ◽  
Sar Data ◽  
Small Baseline ◽  
Mountain Terrains

High mountain terrains, with steep slopes and deep valleys, are generally challenging areas to monitor using satellite earth observation techniques since the terrain creates perspective distortions and differences in illumination that can occlude or obfuscate a significant proportion of the land. This is particularly prominent in synthetic aperture radar (SAR) data, where the oblique geometry can result in large areas of layover and shadow, which must be excluded from any analysis. Interferometric SAR (InSAR) is an established technique for monitoring ground motion and this study assesses its potential for geohazard monitoring in mountainous areas using Lake Sarez in Tajikistan as a case study, applying SAR data from the Sentinel-1 mission. It is shown that, although the effect of layover and shadow is severe, a judicious combination of ascending and descending satellite passes is still capable of surveying 88% of the land surface. It is also demonstrated that, through the use of an advanced InSAR technique (the APSIS™ Intermittent Small Baseline Subset technique), near-complete coverage of ground motion measurements is possible, despite intermittent snow cover. Moreover, this is achieved without the need for ground control, which can be hazardous to establish in such areas. It is concluded that a combination of satellite passes and advanced InSAR techniques greatly facilitates the remote monitoring of ground motion hazards in high mountain areas.

Using small baseline Interferometric SAR to map nonlinear ground motion: a case study in Northern Tibet

2009 ◽  
Vol 3 (3) ◽  
Author(s):  
Zhenhong Li ◽  
Yanxiong Liu ◽  
Xinghua Zhou ◽  
Paul Cross ◽  
Wanpeng Feng
Keyword(s):  
Ground Motion ◽  
Northern Tibet ◽  
Small Baseline ◽  
Interferometric Sar

scholarly journals APPLICATIONS OF SENTINEL-1 SYNTHETIC APERTURE RADAR IMAGERY FOR FLOODS DAMAGE ASSESSMENT: A CASE STUDY OF NAKHON SI THAMMARAT, THAILAND

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1927-1931 ◽  
Author(s):  
G. Dadhich ◽  
H. Miyazaki ◽  
M. Babel
Keyword(s):  
Land Surface ◽  
Local Economic Development ◽  
European Space Agency ◽  
Weather Conditions ◽  
Economic Loss ◽  
Test Site ◽  
Flood Damage ◽  
Recurrent Event ◽  
Sar Data

<p><strong>Abstract.</strong> Flooding is one of the major disasters occurring in various parts of the world. Estimation of economic loss due to flood often becomes necessary for flood damage mitigation. This present practice to carry out post flood survey to estimate damage, which is a laborious and time-consuming task. This paper presents a framework of rapid estimation of flood damage using SAR earth observation satellite data.</p><p>In Nakhon Si Thammarat, a southern province in Thailand, flooding is a recurrent event affecting the entire province, especially the urban area. Every year, it causes lives and damages to infrastructure, agricultural production and severely affects local economic development. In order to monitor and estimate flood damages in near-real time, numerous techniques can be used, from a simply digitizing on maps, to using detailed surveys or remote sensing techniques. However, when using the last-mentioned technique, the results are conditioned by the time of data acquisition (day or night) as well as by weather conditions. Although, these impediments can be surpassed by using RADAR satellite imagery. The aim of this study is to delineate the land surface of Chian Yai, Pak Phanang and Hua Sai districts of that was affected by floods in December 2018 and January 2019. For this case study, Sentinel-1 C-Band SAR data provided by ESA (European Space Agency) were used. The data sets were taken before and after the flood took place, all within 1 days and were processed using Sentinel Toolbox. Cropland mapping has been carried out to assess the agricultural loss in study area using Sentinel-1 SAR data. The thematic accuracy has been assessed for cropland classification for test site shows encouraging overall accuracy as 82.63 % and kappa coefficients (&amp;kappa;) as 0.78.</p>

scholarly journals Predictions of changes of glacier mass balance in the Nepal Himalaya and Tibetan Plateau: a case study of air temperature increase for three glaciers

1992 ◽  
Vol 16 ◽  
pp. 89-94 ◽  
Author(s):  
Yutaka Ageta ◽  
Tsutomu Kadota
Keyword(s):  
Tibetan Plateau ◽  
Equilibrium State ◽  
Mass Balance ◽  
Air Temperature ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Mountain Areas ◽  
Nepal Himalaya ◽  
Ice Cap

Annual mass exchange differs between maritime and continental glaciers. A common characteristic of these glaciers in Asian high-mountain areas is that most of the annual accumulation occurs in summer. Since variations in mass balance of a summer-accumulation type of glacier are quite sensitive to variations in summer air temperature, shrinkages of such glaciers due to climate warming are predicted by the use of simplified experimental relations between air temperature and mass balance, disregarding variation of other climatic variables such as cloudiness and precipitation. The results predict that both small and large maritime glaciers are more sensitive to warming than a continental ice cap. A small glacier would disappear in a few decades if the air temperature persisted a few degrees above that of an equilibrium state of mass balance.

scholarly journals Taking Advantage of the ESA G-POD Service to Study Ground Deformation Processes in High Mountain Areas: A Valle d’Aosta Case Study, Northern Italy

2016 ◽  
Vol 8 (10) ◽  
pp. 852 ◽  
Author(s):  
Martina Cignetti ◽  
Andrea Manconi ◽  
Michele Manunta ◽  
Daniele Giordan ◽  
Claudio De Luca ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Northern Italy ◽  
High Mountain ◽  
Mountain Areas ◽  
Deformation Processes

scholarly journals Climate change over the high-mountain versus plain areas: Effects on the land surface hydrologic budget in the Alpine area and northern Italy

2017 ◽  
Author(s):  
Claudio Cassardo ◽  
Seon Ki Park ◽  
Marco Galli ◽  
Sungmin O
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Climate Model ◽  
Human Life ◽  
Northern Italy ◽  
Future Climate ◽  
High Mountain ◽  
Transfer Scheme ◽  
Mountain Areas ◽  
Alpine Area

Abstract. Climate change may intensify during the second half of the current century. Changes in temperature and precipitation can exert a significant impact on the regional hydrologic cycle. Because the land surface serves as the hub of interactions among the variables constituting the energy and water cycles, evaluating the land surface processes is essential to detail the future climate. In this study, we employ a trusted Soil-Vegetation-Atmosphere Transfer scheme, called the University of Torino model of land Processes Interaction with Atmosphere (UTOPIA), in offline simulations to quantify the hydrologic components changes in the Alpine area and northern Italy, on the basis of regional future climate (FC) conditions produced by the Regional Climate Model version 3 (RegCM3) via the IPCC A2 and B2 scenarios. In FCs, the evapotranspiration generally increases, especially over the plain areas, and consequently the surface soil moisture decreases during summer, falling below the wilting point threshold for one more month compared to present climate. In the high-mountain areas, due to the earlier snow melting, the land surface becomes snowless for an additional month. The annual mean number of dry (wet) days increase remarkably (slightly) in FCs; thus increasing the risk of severe droughts, and slightly increasing the risk of floods coincidently. Our results have serious implications on human life, including agricultural production, water sustainability and general infrastructures, and can be used to plan the managements of water resources, floods, irrigation, forestry, hydropower, and many other relevant activities.

scholarly journals Predictions of changes of glacier mass balance in the Nepal Himalaya and Tibetan Plateau: a case study of air temperature increase for three glaciers

1992 ◽  
Vol 16 ◽  
pp. 89-94 ◽  
Author(s):  
Yutaka Ageta ◽  
Tsutomu Kadota
Keyword(s):  
Tibetan Plateau ◽  
Equilibrium State ◽  
Mass Balance ◽  
Air Temperature ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Mountain Areas ◽  
Nepal Himalaya ◽  
Ice Cap

Annual mass exchange differs between maritime and continental glaciers. A common characteristic of these glaciers in Asian high-mountain areas is that most of the annual accumulation occurs in summer. Since variations in mass balance of a summer-accumulation type of glacier are quite sensitive to variations in summer air temperature, shrinkages of such glaciers due to climate warming are predicted by the use of simplified experimental relations between air temperature and mass balance, disregarding variation of other climatic variables such as cloudiness and precipitation. The results predict that both small and large maritime glaciers are more sensitive to warming than a continental ice cap. A small glacier would disappear in a few decades if the air temperature persisted a few degrees above that of an equilibrium state of mass balance.

scholarly journals Integrating dark diversity and functional traits to enhance nature conservation of epiphytic lichens: a case study from Northern Italy

2021 ◽  
Author(s):  
Diego Pires Ferraz Trindade ◽  
Meelis Pärtel ◽  
Carlos Pérez Carmona ◽  
Tiina Randlane ◽  
Juri Nascimbene
Keyword(s):  
Climate Change ◽  
Nature Conservation ◽  
Functional Traits ◽  
Growth Form ◽  
Northern Italy ◽  
Epiphytic Lichens ◽  
Mountain Areas ◽  
High Elevations ◽  
Harsh Conditions

AbstractMountains provide a timely opportunity to examine the potential effects of climate change on biodiversity. However, nature conservation in mountain areas have mostly focused on the observed part of biodiversity, not revealing the suitable but absent species—dark diversity. Dark diversity allows calculating the community completeness, indicating whether sites should be restored (low completeness) or conserved (high completeness). Functional traits can be added, showing what groups should be focused on. Here we assessed changes in taxonomic and functional observed and dark diversity of epiphytic lichens along elevational transects in Northern Italy spruce forests. Eight transects (900–1900 m) were selected, resulting in 48 plots and 240 trees, in which lichens were sampled using four quadrats per tree (10 × 50 cm). Dark diversity was estimated based on species co-occurrence (Beals index). We considered functional traits related to growth form, photobiont type and reproductive strategy. Linear and Dirichlet regressions were used to examine changes in taxonomic metrics and functional traits along gradient. Our results showed that all taxonomic metrics increased with elevation and functional traits of lichens differed between observed and dark diversity. At low elevations, due to low completeness and harsh conditions, both restoration and conservation activities are needed, focusing on crustose species. Towards high elevations, conservation is more important to prevent species pool losses, focusing on macrolichens, lichens with Trentepohlia and sexual reproduction. Finally, dark diversity and functional traits provide a novel tool to enhance nature conservation, indicating particular threatened groups, creating windows of opportunities to protect species from both local and regional extinctions.

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