scholarly journals Slope Activity Analysis in the Rogun Catchment Area, Tajikistan, using Remote Sensing Techniques

2020 ◽  
Author(s):  
Nina Jones ◽  
Andrea Manconi ◽  
Alexander Strom
Keyword(s):  
Remote Sensing ◽  
Catchment Area ◽  
Surface Displacement ◽  
Tien Shan ◽  
Slope Failures ◽  
Ground Acceleration ◽  
Mountain Areas ◽  
Hazard Potential ◽  
Slope Instabilities ◽  
Remote Sensing Techniques

<p>The stability and lifetime of construction projects in mountain areas are strongly dependent on local slope activity. Hydropower projects in particular are often affected and endangered by landslide damming and flood wave generation due to slope failures, and thus extensive studies of ground surface instability are vital to assess associated hazards. The Rogun Hydropower Project HPP located in Tajikistan in the Vakhsh – Surkhob River network is currently under construction. The site lies within the seismically active Tien Shan and Pamir Mountain ranges of Central Asia and in particular the Peter the First Range. This region is marked by extreme topography, steep slopes and extensive valley networks and has experienced large and catastrophic slope failures in the past, of which a multitude have been triggered by earthquakes of magnitude M≥4. Co-seismic failures are thus common in the area and present a high geotechnical hazard; however, to date no information on active slope instabilities in its catchment area exists.</p><p>Here we present an inventory of slope instabilities in the Rogun Dam catchment area based on optical and synthetic aperture radar differential interferometry (DInSAR) remote sensing techniques. Sentinel-1 multi–temporal differential interferograms are generated for summer periods of 2016 – 2018 to detect surface displacements. Slope velocities are estimated based on a comparison between differential interferograms, while landslide types are identified based on a geomorphological classification. A likelihood analysis is developed to understand the state of activity of slopes and provide a semi-quantitative confidence thereof. The collected data is subsequently integrated to perform spatial and statistical analyses in order to perform a proximity analysis, assess a co-seismic link and evaluate the damming hazard potential to the Rogun HPP. Results show that a clear majority of detected features are located within 10 km of major faults and in zones of high peak ground acceleration, indicating a potential seismic influence or triggering. Some active slopes show an increase in surface displacement after a particular earthquake event and equally suggest a potential link. Moreover, we developed a damming hazard analysis for slopes detected as active in Sentinel-1 differential interferograms, considering the likelihood of movements, their distance to rivers and faults, as well as estimated volume and velocity per year. The results indicate that a total of 29.6 % of all features constitute a high damming hazard potential in case of catastrophic failure, with 4.5 % located within 1 km of the Rogun Dam reservoir. Although many potential sites are not directly on the slopes rising above the future reservoir, hazardous locations in the catchment upstream pose a threat due to possibility of significant outburst floods in case of the dammed lake outburst.</p>

Remote sensing based assessment of hazards from glacier lake outbursts: a case study in the Swiss Alps

2002 ◽  
Vol 39 (2) ◽  
pp. 316-330 ◽  
Author(s):  
Christian Huggel ◽  
Andreas Kääb ◽  
Wilfried Haeberli ◽  
Philippe Teysseire ◽  
Frank Paul
Keyword(s):  
Remote Sensing ◽  
Hazard Assessment ◽  
Swiss Alps ◽  
High Mountain ◽  
Mountain Areas ◽  
Runout Distance ◽  
Hazard Potential ◽  
Empirical Relations ◽  
Scale Levels ◽  
Remote Sensing Techniques

Glacier lakes are a common phenomenon in high mountain areas. Outbursts from glacier lakes have repeatedly caused the loss of human lives as well as severe damage to local infrastructure. In several high mountain ranges around the world, a grave uncertainty about the hazard potential of glacier lakes still exists, especially with respect to the effects of accelerating rates of glacier retreat as a consequence of atmospheric warming. Area-wide detection and modeling of glacier lake hazard potentials is, therefore, a major challenge. In this study, an approach integrating three scale levels allows for the progressive focus on critical glacier lakes. Remote sensing methods for application in glacier lake hazard assessment are presented, and include channel indexing, data fusion, and change detection. Each method matches the requirements of a certain scale level. For estimating potential disaster amplitudes, assessments must be made of maximum discharge and runout distance of outbursts floods and debris flows. Existing empirical relations are evaluated and complementary ones as derived from available data are proposed. Tests with observations from a recent outburst event from a moraine-dammed lake in the Swiss Alps show the basic applicability of the proposed techniques and the usefulness of empirical relations for first hazard assessments. In particular, the observed runout distance of the debris flow resulting from the outburst does not exceed the empirically estimated maximum runout distance. A list of decision criteria and related remote sensing techniques are discussed in conclusion. Such a list is an essential tool for evaluating the hazard potential of a lake. A systematic application of remote sensing based methods for glacier lake hazard assessment is recommended.Key words: glacier lake outburst, hazard potential, remote sensing, empirical parameters.

scholarly journals Assessment of Imja Glacier Lake outburst Flood (GLOF) Risk in Dudh Koshi River Basin using Remote Sensing Techniques

1970 ◽  
Vol 7 (1) ◽  
pp. 75-91 ◽  
Author(s):  
Kamal P Budhathoki ◽  
OR Bajracharya ◽  
BK Pokharel
Keyword(s):  
Remote Sensing ◽  
Risk Assessment ◽  
Statistical Methods ◽  
Linear Regression Analysis ◽  
Coefficient Of Determination ◽  
Lake Area ◽  
Decision Criteria ◽  
Outburst Flood ◽  
Hazard Potential ◽  
Remote Sensing Techniques

Glacier lakes are common phenomena in the Himalaya region of Nepal. Glacier lake outburst floods have repeatedly caused the death tolls and severe damage to downstream infrastructures. In Himalayas, a vital uncertainty about the glacier lake hazard potential still exists, thereby the effects of accelerating rates of glacier retreat and expansion of Glacier Lake could be the wake of recent global warming and resulting climatic changes. The paper, first describes the general different-level approach upon which the study is based. Then, in the methodological part, applicable remote sensing techniques, geographic information system (GIS) and statistical methods are presented. Observed data of lake area, volume, and depth having similar lake characteristics reported in the different literature are used to develop empirical equations by using statistical methods. The values of r2 (coefficient of determination) - obtained are very high (r2=0.939 for depth – area relationship and r2= 0.990 for volume – area relationship). The comparison of the empirical expression clearly indicated that there is more than 90% variation in the dependent variable, lake volume,as explained by the linear regressions in both cases. Area of Imja glacier lake for different years are determined from the available satellite imagery and volume of the Imja glacier lake are estimated using the expression: V = 0.094A1.453.developed from linear regression analysis of the observed data. Similarly, mean depth can be estimated by using the expression: D = 0.94A0.452. After the preparation of maps and data, a scheme of decision criteria for the evaluation of hazard potential of Imja glacier lake is established. A list of decision criteria is a documented set of factors that are used to examine and compare for evaluating the hazard potential of a glacier lake. The empirical scores are given in terms of hazard magnitude for hazard rating. Analysis of Imja glacier lake based on the empirical scoring system clearly indicated that GLOF risk of the possible outburst from Imja glacier lake is MODERATE. A systematic application of remote sensing based methods for glacier lake outburst flood risk assessment is applicable and thus recommended. Keywords: Glacier lake outburst; remote sensing; risk assessment; hazard potential; empirical parameters; climate change DOI: http://dx.doi.org/10.3126/jhm.v7i1.5618 JHM 2010; 7(1): 75-91

scholarly journals On the influence of topographic, geological and cryospheric factors on rock avalanches and rockfalls in high-mountain areas

2012 ◽  
Vol 12 (1) ◽  
pp. 241-254 ◽  
Author(s):  
L. Fischer ◽  
R. S. Purves ◽  
C. Huggel ◽  
J. Noetzli ◽  
W. Haeberli
Keyword(s):  
Slope Failure ◽  
Temporal Distribution ◽  
High Mountain ◽  
European Alps ◽  
Permafrost Degradation ◽  
Slope Failures ◽  
Mountain Areas ◽  
Investigation Area ◽  
Rock Avalanches ◽  
Slope Instabilities

Abstract. The ongoing debate about the effects of changes in the high-mountain cryosphere on rockfalls and rock avalanches suggests a need for more knowledge about characteristics and distribution of recent rock-slope instabilities. This paper investigates 56 sites with slope failures between 1900 and 2007 in the central European Alps with respect to their geological and topographical settings and zones of possible permafrost degradation and glacial recession. Analyses of the temporal distribution show an increase in frequency within the last decades. A large proportion of the slope failures (60%) originated from a relatively small area above 3000 m a.s.l. (i.e. 10% of the entire investigation area). This increased proportion of detachment zones above 3000 m a.s.l. is postulated to be a result of a combination of factors, namely a larger proportion of high slope angles, high periglacial weathering due to recent glacier retreat (almost half of the slope failures having occurred in areas with recent deglaciation), and widespread permafrost occurrence. The lithological setting appears to influence volume rather than frequency of a slope failure. However, our analyses show that not only the changes in cryosphere, but also other factors which remain constant over long periods play an important role in slope failures.

scholarly journals G.I.S. technologies for data collection, management and visualization of large slope instabilities: two applications in the Western Italian Alps

2004 ◽  
Vol 4 (2) ◽  
pp. 197-211 ◽  
Author(s):  
M. Giardino ◽  
D. Giordan ◽  
S. Ambrogio
Keyword(s):  
Remote Sensing ◽  
Data Collection ◽  
Single Case ◽  
Regional Distribution ◽  
Slope Instability ◽  
Geographical Information ◽  
Local Analysis ◽  
Italian Alps ◽  
Mountain Areas ◽  
Slope Instabilities

Abstract. Large slope instabilities are gravitational phenomena whose main characteristics are the multi-km2 area extension and the complex geometrical, geomorphological and geomechanical settings. Several studies outlined their importance in spatial and temporal occurrence of natural hazards on wide mountain areas and their possible interaction in human activities. For the study of large slope instability and deep seated slope gravitational deformations in the Susa and Aosta Valleys (Western Italian Alps) a complete multiscale program (spatial and temporal) analysis has been performed, giving contributions to the reconstruction and settings of their possible evolution. A complex geodatabase has been created, including thematic elements from field-data collection (geomorphology, hydrology, lithology, structural geology) and instability events analysis from data archives and remote sensing images. To facilitate the management of a large amount of collected data a G.I.S. (Geographical Information System) has been developed, including two main levels of information: local and regional. Local information is mainly devoted to detailed geothematic mapping of single instability phenomena. Clot Brun case study is presented, where original and derived landslide features have been elaborated through arithmetical and statistical operations, in order to identify different instability zones and to assess displacements and state of activity through-time. Regional information collected for a landslide inventory of Aosta Valley (IFFI project) summarizes historical and remote sensing data, combined with metadata from local analysis, in order to assess spatial and temporal hazards. To avoid problems of data accuracy (quality and positioning) due to different source archives, a semi-automatic system for selection and validation of data has been created, based on their spatial characteristics (buffer analysis and control). G.I.S. technologies have been used to archive, manage and visualize collected data through 2-D and 3-D models of single case studies and regional distribution of large slope instabilities.

scholarly journals Active landslides in the Rogun Catchment, Tajikistan, and their river damming hazard potential

Landslides ◽  
2021 ◽  
Author(s):  
Nina Jones ◽  
Andrea Manconi ◽  
Alexander Strom
Keyword(s):  
Satellite Imagery ◽  
Land Use Planning ◽  
Slope Failures ◽  
Regional Seismicity ◽  
Hazard Potential ◽  
River Damming ◽  
Hydropower Plants ◽  
Surface Displacements ◽  
Slope Instabilities ◽  
Under Construction

AbstractThe region of Tajikistan where the Rogun Hydropower Project is currently under construction has experienced large and catastrophic slope failures in the past, often triggered by earthquakes. Co-seismic slope failures are thus common and pose a high hazard potential; however, to date, no specific analysis of slope activity in this area has been presented in international journals. Here, we present an inventory of active landslides identified through satellite imagery analysis and in particular by exploiting space-borne differential radar interferometry. Surface displacements provide the basis for the detection of active slope instabilities, which are then further classified by using geomorphological indicators visible in optical satellite imagery. Additionally, the proximity of active landslides to tectonic lineaments, as well as regional seismicity, is analysed to investigate potential relationships and to provide an integrated river damming hazard potential. The results show that approximately 31% of all detected landslides would have a high damming hazard potential upon catastrophic failure, highlighting the importance of such phenomena for efficient long-term land use planning and management of hydropower plants.

scholarly journals Remote Sensing Calculation of the Influence of Wildfire on Erosion in High Mountain Areas

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1459
Author(s):  
Yolanda Sánchez Sánchez ◽  
Antonio Martínez Graña ◽  
Fernando Santos- Francés
Keyword(s):  
Remote Sensing ◽  
Fire Severity ◽  
High Mountain ◽  
Mountain Areas ◽  
High Severity ◽  
Natural Reserve ◽  
Remote Sensing Techniques ◽  
Normalized Burn Ratio ◽  
The Moment ◽  
Very High

Soil erosion is one of the most important environmental problems of the moment, especially in areas affected by wildfires. In this paper, we study pre-fire and post-fire erosion using remote sensing techniques with Sentinel-2 satellite images and LiDAR. The Normalized Burn Ratio is used to determine the areas affected by the fire that occurred on 18 August 2016 in the Natural Reserve of Garganta de los Infiernos (Cáceres). To calculate the erosion, the multi-criteria analysis is carried out from the RUSLE. Once all calculations were performed, there was a considerable increase in sediment production from 16 June 2016 (pre-fire) with an erosion of 31 T/ha·year to 16 June 2017 of 74 T/ha·year for areas of moderate fire severity, and an increase from 11 T/ha·year in 2016 to 70 T/ha·year for areas with a very high severity. From the NDVI, it was possible to verify that this also affected the recovery of post-fire vegetation, decreasing the NDVI index 0.36 in areas of moderate severity and 0.53 in areas of very high severity.

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