scholarly journals Geomorphological and Climatic Drivers of Thermokarst Lake Area Increase Trend (1999–2018) in the Kolyma Lowland Yedoma Region, North-Eastern Siberia

2021 ◽  
Vol 13 (2) ◽  
pp. 178
Author(s):  
Alexandra Veremeeva ◽  
Ingmar Nitze ◽  
Frank Günther ◽  
Guido Grosse ◽  
Elizaveta Rivkina
Keyword(s):  
Landsat Imagery ◽  
Lake Basin ◽  
Lake Area ◽  
The Holocene ◽  
Thermokarst Lake ◽  
Digital Elevation ◽  
Area Increase ◽  
High Precipitation ◽  
Elevation Model ◽  
Map Data

Thermokarst lakes are widespread in Arctic lowlands. Under a warming climate, landscapes with highly ice-rich Yedoma Ice Complex (IC) deposits are particularly vulnerable, and thermokarst lake area dynamics serve as an indicator for their response to climate change. We conducted lake change trend analysis for a 44,500 km2 region of the Kolyma Lowland using Landsat imagery in conjunction with TanDEM-X digital elevation model and Quaternary Geology map data. We delineated yedoma–alas relief types with different yedoma fractions, serving as a base for geospatial analysis of lake area dynamics. We quantified lake changes over the 1999–2018 period using machine-learning-based classification of robust trends of multi-spectral indices of Landsat data and object-based long-term lake detection. We analyzed the lake area dynamics separately for 1999–2013 and 1999–2018 periods, including the most recent five years that were characterized by very high precipitation. Comparison of drained lake basin area with thermokarst lake extents reveal the overall limnicity decrease by 80% during the Holocene. Current climate warming and wetting in the region led to a lake area increase by 0.89% for the 1999–2013 period and an increase by 4.15% for the 1999–2018 period. We analyzed geomorphological factors impacting modern lake area changes for both periods such as lake size, elevation, and yedoma–alas relief type. We detected a lake area expansion trend in high yedoma fraction areas indicating ongoing Yedoma IC degradation by lake thermokarst. Our concept of differentiating yedoma–alas relief types helps to characterize landscape-scale lake area changes and could potentially be applied for refined assessments of greenhouse gas emissions in Yedoma regions. Comprehensive geomorphological inventories of Yedoma regions using geospatial data provide a better understanding of the extent of thermokarst processes during the Holocene and the pre-conditioning of modern thermokarst lake area dynamics.

scholarly journals Lake Onego development in the late glacial assessed with the use of GIS technologies

2019 ◽  
pp. 83-90 ◽  
Author(s):  
D. A. Subetto ◽  
M. S. Potakhin ◽  
M. B. Zobkov ◽  
A. Yu. Tarasov ◽  
T. S. Shelekhova ◽  
...  
Keyword(s):  
Drainage Basin ◽  
Sediment Cores ◽  
Late Glacial ◽  
Lake Basin ◽  
Lake Area ◽  
Digital Maps ◽  
Digital Elevation ◽  
Spatial Parameters ◽  
Elevation Model ◽  
Maximum Development

The GIS-based reconstructions of Lake Onego development in the Late Glacial (14500–12300 yrs ago) were performed. Reconstructions have been based on the deglaciation model of the Lake Onego depression, digital elevation model of the lake depression, SRTM model of its drainage basin and on the data obtained from the palaeolimnological studies of numerous lake sediment cores. This allowed us to distinguish six main stages of the lake development for which a series of detailed schemes were produced. 1. Formation of the ice-dammed lake as a result of the ice sheet retreating (14.5 cal ka BP). 2. Emerging of the southern and central parts of the lake basin from the ice cover (14.0 cal ka BP). 3. The maximum development of the proglacial lake (13.3 cal ka BP). The lake area in this period was around 33 000 km2. 4. The first regression (13.2 ka BP). 5. The second regression (12.4 ka BP). 6. The third regression (12.3 ka BP), when the area of the lake dropped to 18 000 km2. We created detailed digital maps of the main stages of Lake Onego development during the Late Glacial and calculated the spatial parameters of the lake. The quantitative data obtained in this study would be used in estimation of the volumes of the lake and outflow discharges in the past. Maps are available in electronic form.

scholarly journals LANDSLIDE SUSCEPTIBILITY MODELLING IN SELECTED STATES ACROSS SE. NIGERIA

2020 ◽  
Vol 4 (1) ◽  
pp. 23-27
Author(s):  
R. O. E. Ulakpa ◽  
V.U.D. Okwu ◽  
K. E. Chukwu ◽  
M. O. Eyankware
Keyword(s):  
Landslide Susceptibility ◽  
Landsat Imagery ◽  
Control Measures ◽  
Landslide Risk ◽  
Susceptibility Map ◽  
Landsat 8 ◽  
Aerial Photos ◽  
Anambra State ◽  
Digital Elevation ◽  
Elevation Model

Identification and mapping of landslide is essential for landslide risk and hazard assessment. This paper gives information on the uses of landsat imagery for mapping landslide areas ranging in size from safe area to highly prone areas. Landslide mitigation largely depends on the understanding of the nature of the factors namely: slope, soil type, lineament, lineament density, elevation, rainfall and vegetation. These factors have direct bearing on the occurrence of landslide. Identification of these factors is of paramount importance in setting out appropriate and strategic landslides control measures. Images for this study was downloaded by using remote sensing with landsat 8 ETM and aerial photos using ArcGIS 10.7 and Surfer 8 software, while Digital Elevation Model (DEM) and Google EarthPro TM were used to produce slope, drainage, lineament and elevation. From the processed landsat 8 imagery, landslide susceptibility map was produced, and landslide was category into various class; low, medium and high. From the study, it was observed that Enugu and Anambra state ranges from high to medium in terms of landslide susceptibility, Imo state ranges from medium to low.

scholarly journals Analisis Spasial Bencana Longsor Bukit Telogolele Kabupaten Banjarnegara Menggunakan Data Foto Udara UAV

2017 ◽  
Vol 1 (1) ◽  
pp. 77
Author(s):  
Ruli Andaru ◽  
Purnama Budi Santosa
Keyword(s):  
Spatial Data ◽  
3D Analysis ◽  
Geospatial Information ◽  
Aerial Photos ◽  
Vehicle Data ◽  
Digital Elevation ◽  
Before And After ◽  
Elevation Model ◽  
Digital Orthophoto ◽  
Map Data

Spatial data is a very important role in emergency command and disaster management, before, during or post disasters. When a disaster occurs, the currently geospatial information is very needed: where the center of the disaster, the area affected, the volumetric of the landslide, what facilities are damaged, and determine the location of temporary shelters. This study examines and analyze the landslide in Banjarnegara 2014 before and after the landslide using Peta Rupa Bumi Indonesia (RBI) and the UAV Aerial Photos (Unmanned Aerial Vehicle). Data before the landslide obtained from RBI, while data after landslide obtained by performing aerial photography using fixed-wing UAV in December 2014 and August 2015. These aerial photos processing with photogrammetry to produce digital orthophoto and DEM (Digital Elevation Model). Orthophoto and DEM data is used to perform geospatial analysis in both 2D and 3D. 3D analysis obtained from the extraction of DEM elevation map data values appearance of the earth (RBI) and the UAV Aerial Photo. Analysis was conducted on the four components: contouring, terrain profile/cross section, slope/gradient, and volumetric (cut and fill). Readiness management of geospatial data and information is necessary to minimize losses and speed up the process of rehabilitation and reconstruction in the areas affected by the disaster. With this spatial analysis, the estimated of volume of landslides, mapping the facility affected, and the manufacture of the soil profile (high landslide, landslide affected area) can be performed quickly and accurately.

scholarly journals Spatial and Temporal Variation of Net Snow Accumulation in a Small Alpine Watershed, Emerald Lake Basin, Sierra Nevada, California, U.S.A.

1989 ◽  
Vol 13 ◽  
pp. 56-63 ◽  
Author(s):  
K. Elder ◽  
J. Dozier ◽  
J. Michaelsen
Keyword(s):  
Sierra Nevada ◽  
Field Measurements ◽  
Snow Accumulation ◽  
Spatial And Temporal Variation ◽  
Lake Basin ◽  
Snow Properties ◽  
Digital Elevation ◽  
Snow Water ◽  
Elevation Model ◽  
Topographic Parameters

Distribution of snow-water equivalence (SWE) in the Emerald Lake watershed located in Sequoia National Park, California, U.S.A, was examined during the 1987 water year. Elevations at this site range from 2780 to 3416 m a.s.l., and the total watershed area is about 122 ha. A stratified sampling scheme was evaluated by identifying and mapping zones of similar snow properties, based on topographic parameters that account for variations in both accumulation and ablation of snow. Elevation, slope, and radiation values calculated from a digital elevation model were used to identify these zones. Field measurements of SWE were combined with characteristics of the sample locations and clustered to identify similar classes of SWE. The entire basin was then partitioned into zones for each set of survey data. The topographic parameters of the basin used in classification, namely slope and elevation, are constant in time and did not change between survey dates. The radiation data showed temporal variability providing a physically justified basis for changes in SWE distribution through time. Although results do not identify which of the classification attempts is superior to the others, net radiation is clearly of primary importance, and slope and elevation appear to be important to a lesser degree. The peak accumulation for the 1987 water year was 598 mm SWE, which is about half the 50 year mean.

scholarly journals UAV-Derived Himalayan Topography: Hazard Assessments and Comparison with Global DEM Products

Drones ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 18 ◽  
Author(s):  
C. Watson ◽  
Jeffrey Kargel ◽  
Babulal Tiruwa
Keyword(s):  
Mass Movement ◽  
High Mountain ◽  
Lake Area ◽  
Digital Elevation ◽  
2015 Gorkha Earthquake ◽  
Order Of Magnitude ◽  
Hazard Assessments ◽  
Elevation Model ◽  
Terrain Elevation ◽  
Fine Resolution

Topography derived using human-portable unmanned aerial vehicles (UAVs) and structure from motion photogrammetry offers an order of magnitude improvement in spatial resolution and uncertainty over small survey extents, compared to global digital elevation model (DEM) products, which are often the only available choice of DEMs in the high-mountain Himalaya. Access to fine-resolution topography in the high mountain Himalaya is essential to assess where flood and landslide events present a risk to populations and infrastructure. In this study, we compare the topography of UAV-derived DEMs, three open-access global DEM products, and the 8 m High Mountain Asia (HMA) DEMs (released in December 2017) and assess their suitability for landslide- and flood-related hazard assessments. We observed close similarity between UAV and HMA DEMs when comparing terrain elevation, river channel delineation, landside volume, and landslide-dammed lake area and volume. We demonstrate the use of fine-resolution topography in a flood-modelling scenario relating to landslide-dammed lakes that formed on the Marsyangdi River following the 2015 Gorkha earthquake. We outline a workflow for using UAVs in hazard assessments and disaster situations to generate fine-resolution topography and facilitate real-time decision-making capabilities, such as assessing landslide-dammed lakes, mass movement volumes, and flood risk.

scholarly journals Spatial and Temporal Variation of Net Snow Accumulation in a Small Alpine Watershed, Emerald Lake Basin, Sierra Nevada, California, U.S.A.

1989 ◽  
Vol 13 ◽  
pp. 56-63 ◽  
Author(s):  
K. Elder ◽  
J. Dozier ◽  
J. Michaelsen
Keyword(s):  
Sierra Nevada ◽  
Field Measurements ◽  
Snow Accumulation ◽  
Spatial And Temporal Variation ◽  
Lake Basin ◽  
Snow Properties ◽  
Digital Elevation ◽  
Snow Water ◽  
Elevation Model ◽  
Topographic Parameters

Distribution of snow-water equivalence (SWE) in the Emerald Lake watershed located in Sequoia National Park, California, U.S.A, was examined during the 1987 water year. Elevations at this site range from 2780 to 3416 m a.s.l., and the total watershed area is about 122 ha. A stratified sampling scheme was evaluated by identifying and mapping zones of similar snow properties, based on topographic parameters that account for variations in both accumulation and ablation of snow. Elevation, slope, and radiation values calculated from a digital elevation model were used to identify these zones. Field measurements of SWE were combined with characteristics of the sample locations and clustered to identify similar classes of SWE. The entire basin was then partitioned into zones for each set of survey data. The topographic parameters of the basin used in classification, namely slope and elevation, are constant in time and did not change between survey dates. The radiation data showed temporal variability providing a physically justified basis for changes in SWE distribution through time. Although results do not identify which of the classification attempts is superior to the others, net radiation is clearly of primary importance, and slope and elevation appear to be important to a lesser degree. The peak accumulation for the 1987 water year was 598 mm SWE, which is about half the 50 year mean.

scholarly journals Development of a subglacial lake monitored with radio-echo sounding: Case study from the Eastern Skaftá Cauldron in the Vatnajökull ice cap, Iceland

2021 ◽  
Author(s):  
Eyjólfur Magnússon ◽  
Finnur Pálsson ◽  
Magnús T. Gudmundsson ◽  
Thórdís Högnadóttir ◽  
Cristian Rossi ◽  
...  
Keyword(s):  
Lake Area ◽  
Ice Cap ◽  
Lake Volume ◽  
Digital Elevation ◽  
Geothermal Activity ◽  
Before And After ◽  
Radio Echo Sounding ◽  
Water Volumes ◽  
Elevation Model ◽  
Echo Sounding

Abstract. We present repeated radio-echo sounding (RES, 5 MHz) on a profile grid over the Eastern Skaftá Cauldron (ESC) in Vatnajökull ice cap, Iceland. The ESC is ~3 km wide and 50–150 m deep ice cauldron created and maintained by subglacial geothermal activity of ~1 GW. Beneath the cauldron and 200–400 m thick ice, water accumulates in a lake and is released semi-regularly in jökulhlaups. The RES record consists of annual surveys with 200–400 m between profiles in early summers of 2014–2020. Comparison of the RES surveys (2D migrated profiles) reveals variable lake area (0.5–4.1 km2) and enables traced reflections from the lake roof to be distinguished from bedrock reflections. This allows construction of a digital elevation model (DEM) of the bedrock in the area, further constrained by two borehole measurements at the cauldron centre. It also allows creation of lake thickness maps and an estimate of lake volume at the time of each survey, which we compare with lowering patterns and released water volumes obtained from surface DEMs obtained before and after jökulhlaups. The estimated lake volume is 250 × 106 m3 in June 2015 but 320 ± 20 × 106 m3 drained from the cauldron in October 2015. In June 2018, RES profiles reveal a lake volume of 185 × 106 m3 while 220 ± 30 × 106 m3 was released in a jökulhlaup in August 2018. Considering the water accumulation over the periods between RES surveys and jökulhlaups, this indicates 10–20 % uncertainty in the RES-derived volumes at times when significant jökulhlaups may be expected.

scholarly journals Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan

Geosciences ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 468
Author(s):  
Mirlan Daiyrov ◽  
Chiyuki Narama ◽  
Andreas Kääb ◽  
Takeo Tadono
Keyword(s):  
Tien Shan ◽  
Glacial Lake ◽  
Lake Basin ◽  
Lake Area ◽  
Outburst Flood ◽  
Field Surveys ◽  
Digital Elevation ◽  
Summer Temperatures ◽  
Satellite Radar ◽  
Northern Tien Shan

In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudden drainage on 8 August 2019 of the Toguz-Bulak glacial lake in the Tosor river basin of the northern Tien Shan region. In this study, we used remote sensing and field surveys to examine the reasons for the outburst. We found that the lake area changed from 0.021 km² to 0.002 km2 due to the outburst, in which most of the initial 130,000 m3 of water discharged within four hours. In examining the longer-term behavior of this lake, we found that from 2010 through 2019, it appears in June and disappears in September every year. Its maximum area occurs in late July and early August. With the expansion of the lake basin between 2010 and 2019, the lake also increased greatly in size, particularly so in the three years before the outburst, linked to high summer temperatures and the resulting higher inflow of glacier meltwater, finally leading to the sudden drainage in 2019. Before this outburst, a 2-m high moraine dam retained the lake. Continuously inflowing meltwater and the related increasing pressure by the lake water mass eventually broke the moraine dam. Satellite radar interferometry revealed active displacement fringes in the lake basin and moraine dam due to the melting and subsidence of buried ice. An analysis using digital elevation models from 1964 and 2010 also confirms the surface lowering in the lake basin by up to 8.5 m and on the moraine dam by 2 m. Such lowering of the proglacial moraine complex destabilized the moraine dam.

scholarly journals Technical Methodology for ASTER Global Water Body Data Base

2018 ◽  
Author(s):  
Hiroyuki Fujisada ◽  
Minoru Urai ◽  
Akira Iwasaki
Keyword(s):  
Sea Ice ◽  
Water Body ◽  
Lake Area ◽  
Unique Challenge ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Elevation Data ◽  
Data Points ◽  
Data Files ◽  
Elevation Model

A waterbody detection technique is an essential part of digital elevation model (DEM) generation to delineate land-water boundaries and set flattened elevations. This paper describes the technical methodology for improving the initial tile-based waterbody data that are created during production of the ASTER GDEM, because without improvement such tile-based waterbody data are not suitable for incorporating into the new ASTER GDEM Version 3. Waterbodies are classified into three categories: sea, lake, and river. For sea-waterbodies, the effect of sea ice is removed to better delineate sea shorelines in high latitude areas, because sea ice prevents accurate delineation of sea shorelines. For lake-waterbodies, the major part of the processing is to set the unique elevation value for each lake using a mosaic image that covers the entire lake area. Rivers present a unique challenge, because their elevations gradually step down from upstream to downstream. Initially, visual inspection is required to separate rivers from lakes. A stepwise elevation assignment, with a step of one meter, is carried out by manual or automated methods, depending on the situation. The ASTER GWBD product consists of a global set of 1º latitude-by-1º longitude tiles containing water body attribute and elevation data files in geographic latitude and longitude coordinates and with one arc second posting. Each tile contains 3601-by-3601 data points. All improved waterbody elevation data are incorporated into the ASTER GDEM to reflect the improved results.

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