scholarly journals Using aerial photography to study glacier changes in Norway

2002 ◽  
Vol 34 ◽  
pp. 343-348 ◽  
Author(s):  
Liss Marie Andreassen ◽  
Hallgeir Elvehøy ◽  
Bjarne Kjøllmoen
Keyword(s):  
Aerial Photography ◽  
Traditional Method ◽  
Aerial Photographs ◽  
Multiple Models ◽  
Volume Loss ◽  
Traditional Methods ◽  
Digital Terrain ◽  
Terrain Models ◽  
Glacier Changes ◽  
The 1960S

AbstractThe Norwegian Water Resources and Energy Administration has photographed glacial areas in Norway for several decades. Detailed maps or digital terrain models have been made for selected glaciers from vertical aerial photographs. Multiple models of seven glaciers have been used here to calculate glacier volume change during the time between mappings using the geodetic method. Analyses and results are presented and compared with traditional mass-balance measurements. We estimated uncertainties of ±1.3–2.7mw.e. for the geodetic method, and ±1.3 –3.5mw.e. for the traditional method. The discrepancies between the methods varied between 0.4 and 4.7 mw.e. All glaciers decreased in volume from the 1960s/70s to the 1990s, except Hardangerjøkulen. This glacier experienced a significant increase in volume: the geodetic and traditional methods showed net balance values of +6.8m and +9.4mw.e., respectively. Trollbergdalsbreen had the largest total volume loss: the geodetic and traditional methods showed net balance values of –12.3 and –16.8mw.e.

Improving the accuracy of forming a digital terrain model along the railway

2021 ◽  
pp. 22-29
Author(s):  
Dmitriy A. Roshchin
Keyword(s):  
High Efficiency ◽  
Digital Terrain Model ◽  
Digital Processing ◽  
Aerial Photographs ◽  
Railway Track ◽  
Technical Solution ◽  
Digital Terrain Models ◽  
Terrain Model ◽  
Digital Terrain ◽  
Terrain Models

The problem of improving the accuracy of digital terrain models created for monitoring and diagnostics of the railway track and the surrounding area is considered. A technical solution to this problem is presented, which includes a method for joint aerial photography and laser scanning, as well as a method for digital processing of the obtained data. The relevance of using this solution is due to the existence of zones of weak reception of signals from the global navigation satellite system, since in these zones the accuracy of constructing digital terrain models using currently used diagnostic spatial scanning systems is reduced. The technical solution is based on the method of digital processing of aerial photographs of the railway track. In this case, as elements of external orientation, the threads of the rail track located at a normalized distance from each other are used. The use of this method made it possible to increase the accuracy of determining the flight path of an aircraft over railway tracks and, as a result, the accuracy of calculating the coordinates of points on the earth's surface. As a result, a digital terrain model was created that is suitable for diagnostics and monitoring the condition of the railway trackbed. During simulation modeling, it was found that the application of the proposed method allowed to reduce to 50 % the confidence interval of the distribution of the error in determining the coordinates of points on the terrain and increase the accuracy of forming a digital terrain model. This promising technical solution for improving the accuracy of digital terrain models for railway track diagnostics is implemented using unmanned aerial vehicles that are part of the mobile diagnostic complex. The advantages of the proposed solution include high efficiency and availability of application.

scholarly journals Changing the geometry of basins and water resources of Lakes Gopło and Ostrowskie under the influence of anthropopressure

2014 ◽  
Vol 14 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Piasecki Adam ◽  
Skowron Rajmund
Keyword(s):  
Water Resources ◽  
Surface Area ◽  
Water Cycle ◽  
Field Measurements ◽  
Aerial Photographs ◽  
Maximum Width ◽  
Digital Terrain ◽  
Terrain Models ◽  
Basic Parameters ◽  
Area And Volume

Abstract The paper presents the changes that have occurred in the morphometry of Lakes Gopło and Ostrowskie, which are located in central Poland. The analysis covered the period characterised by increased human interference into the water cycle, which has been taking place continually since the mid-eighteenth century. On the basis of available cartographic materials (aerial photographs, topographic maps, bathymetric charts of the lakes) and the authors’ own field measurements digital terrain models were developed for the immediate environment of the surveyed lakes. These models, in turn, were used for measuring basic parameters characterising the external dimensions of the lakes (surface area, length and maximum width, shoreline length) and their underwater relief (volume, maximum and average depth). In addition, the selected indicators of the shape and form of the lake basins were determined. The results showed a drastic reduction of water resources of the two lakes. The basin of Lake Gopło covers only the deepest parts of the former reservoir, accounting for only 23.3% of the lake before 1772, and 32.5% of its former volume. In the case of Lake Ostrowskie the surface area and volume decreased, respectively, by 23.5% (74.9 ha) and 21.3% (6 695 000 m3). Such large changes in surface area and volume of both lakes have contributed to significant changes in other morphometric parameters and indicators. In particular, significant changes were observed in relation to such morphometric characteristics as length and maximum width, as well as average and maximum depth.

Mapping of Greenland landscape using aerial photography and orthophotography (Technical Note)

2013 ◽  
Vol 3 (2) ◽  
pp. 208-212
Author(s):  
Petr Vávrů ◽  
Helge Viken
Keyword(s):  
High Resolution ◽  
Aerial Photography ◽  
Local Scale ◽  
Technical Note ◽  
Western Coast ◽  
Natural Landscape ◽  
Aerial Photos ◽  
Digital Terrain ◽  
Terrain Models ◽  
Contour Lines

Aerial photography is an important tool for mapping on local scale. In the paper, description of aerial photos taken over several urban and natural landscape sites in West Greenland is given as well as their processing. Using a high-resolution software, aerial photos were processed and digital terrain models (DTMs) of the sites produced. Technique of contour lines was used to check the created DTM for particular site. Finally, orthophotos of all sites were produced. In this Technical Note, several sites located on Western coast of Greenland are presented and the use of maps generated from orthophotos is discussed.

scholarly journals Glacier change of the Columbia Icefield, Canadian Rocky Mountains, 1919–2009

2013 ◽  
Vol 59 (216) ◽  
pp. 671-686 ◽  
Author(s):  
Christina Tennant ◽  
Brian Menounos
Keyword(s):  
Volume Change ◽  
Rocky Mountains ◽  
Relative Length ◽  
Aerial Photographs ◽  
Glacier Change ◽  
Volume Loss ◽  
Canadian Rocky Mountains ◽  
Elevation Change ◽  
Glacier Changes ◽  
Length And Area

AbstractWe determined length, area, elevation and volume change of the Columbia Icefield using Interprovincial Boundary Commission Survey maps from 1919, eight sets of aerial photographs from 1948 to 1993, and satellite data from 1999 to 2009. Over the period 1919–2009, glaciers on average retreated 1150 ± 34 m and shrank by 2.4 ± 0.2 km2. Total area loss was 59.6 ± 1.2 km2 (23 ± 5%), and mean elevation change was −49 ± 25 m w.e., resulting in a total volume loss of 14.3 ± 2.0 km3 w.e. Large outlet glaciers experienced the greatest absolute ice loss, while small, detached glaciers lost the most relative length and area. Thinning rates of debris-covered ice were 30–60% lower than those for clean ice. All glacier changes were significantly correlated with each other (p < 0.01), with r values ranging from 0.54 to 0.82. Temperature is correlated with length and area change over periods lagged 1–5 years (p < 0.05), and with elevation and volume change over periods lagged 9–18 years (p < 0.05). Precipitation is correlated with glacier change over periods lagged 1–10 years (p < 0.05).

scholarly journals Application of the SHALSTAB model for the identification of areas susceptible to landslides: Brazilian case studies.

2017 ◽  
Vol 19 (1) ◽  
pp. 136-144 ◽  
Author(s):  
MARTINS Tiago Damas ◽  
VIEIRA Bianca Carvalho ◽  
FERNANDES Nelson Ferreira ◽  
OKAFIORI Chisato ◽  
MONTGOMERY David R.
Keyword(s):  
Shallow Landslides ◽  
Light Detection And Ranging ◽  
Economic Losses ◽  
Mass Movements ◽  
Digital Terrain ◽  
Terrain Models ◽  
Susceptibility Maps ◽  
Mathematical Equations ◽  
The 1960S ◽  
Topographical Maps

Since the 1960s, catastrophic and generalized events of hazardous mass movements caused millions of dollars in economic losses and resulted in thousands of fatalities and homelessness in Brazil. To understand these processes and attempt to predict them, mathematical models have been utilized world-wide describing the physics of the process through mathematical equations. The objective of this study was to present two areas widely affected by shallow landslides where the SHALSTAB model was applied to understand the process and to predict potentially unstable areas in several hydrographic basins. Simulations utilized the types of distinct data that were available in each area. From both areas, geotechnical data collected in the field, topographical data from digital topographical maps and Digital Terrain Models (DTM) from Light Detection and Ranging (LiDAR) were utilized. Susceptibility maps were validated using two indexes, scar concentration (SC) and landslide potential (LP), based on landslides that occurred in 1985 and 2011. Both indexes showed satisfactory results given that the unconditionally unstable category described more than 45% of the landslide events, and the LP index displayed the highest values for the most unstable categories.

scholarly journals Planimetric and volumetric glacier changes in the Khumbu Himal, Nepal, since 1962 using Corona, Landsat TM and ASTER data

2008 ◽  
Vol 54 (187) ◽  
pp. 592-600 ◽  
Author(s):  
Tobias Bolch ◽  
Manfred Buchroithner ◽  
Tino Pieczonka ◽  
André Kunert
Keyword(s):  
Digital Terrain Model ◽  
Landsat Tm ◽  
Glacier Area ◽  
Volume Loss ◽  
Terrain Model ◽  
Investigation Area ◽  
Digital Terrain ◽  
Ice Coverage ◽  
Glacier Changes ◽  
Debris Coverage

AbstractMultitemporal space imagery from 1962 (Corona KH-4), 1992 (Landsat TM), 2001 and 2005 (Terra ASTER) was used to investigate the glacier changes in the Khumbu Himal, Nepal. The ice coverage in the investigation area decreased by about 5% between 1962 and 2005, with the highest retreat rates occurring between 1992 and 2001. The debris coverage increased concomitantly with the decrease in total glacier area. The clean-ice area decreased by >10%. Digital terrain model (DTM) generation from the early Corona KH-4 stereo data in this high-relief terrain is time-consuming, and the results still contain some elevation errors. However, these are minor in the snow-free areas with gentle slopes. Thus comparison of the surfaces of the debris-covered glacier tongues based on the Corona DTM and an ASTER DTM is feasible and shows the downwasting of the debris-covered glaciers. The highest downwasting rates, more than 20 m (>0.5 m a−1), can be found near the transition zone between the active and the stagnant glacier parts of the debris-covered glacier tongues. The downwasting is lower, but still evident, in the active ice areas and at the snout with thick debris cover. All investigated debris-covered glaciers in the study area show similar behaviour. The estimated volume loss for the investigated debris-covered glacier tongues is 0.19 km3.

scholarly journals The new Landsat-derived glacier inventory for Jotunheimen, Norway, and deduced glacier changes since the 1930s

2008 ◽  
Vol 2 (3) ◽  
pp. 299-339 ◽  
Author(s):  
L. M. Andreassen ◽  
F. Paul ◽  
A. Kääb ◽  
J. E. Hausberg
Keyword(s):  
Reference Data ◽  
Mapping Method ◽  
Aerial Photographs ◽  
Glacier Inventory ◽  
Digital Maps ◽  
Area Reduction ◽  
Glacier Changes ◽  
Automatic Mapping ◽  
The 1960S ◽  
And Control

Abstract. A Landsat Thematic Mapper (TM) scene from 2003 covering the Jotunheimen and Breheimen region has been used to map the recent glacier extents using thresholded ratio images (TM3/TM5). Orthoprojected aerial photographs and glacier outlines from digital maps have been used to validate the method and control the results. We further calculated glacier changes by comparing the Landsat-derived 2003 glacier outlines with previous maps and inventories from the 1930s, 1960s and 1980s. Our results confirm that the applied automatic mapping method is very robust and agrees precisely with the reference data used. Some manual editing was necessary to correct the outline at ice-lake contacts and at debris covered glaciers. However, for most of the glaciers no corrections were required. The most laborious task has been to assign ID numbers and couple the new Landsat inventory to previous inventories to assess area changes. The glaciers investigated shrank since the 1930s with an overall area reduction of about 23% for 38 glaciers. Since the 1960s the area reduction was 12% for 164 glaciers. Although the general trend is glacier retreat and area reduction, some glaciers have increased their size or remained nearly unchanged over the last decades.

scholarly journals Glacier change and climate forcing in recent decades at Gran Campo Nevado, southernmost Patagonia

2007 ◽  
Vol 46 ◽  
pp. 136-144 ◽  
Author(s):  
M. Möller ◽  
C. Schneider ◽  
R. Kilian
Keyword(s):  
Climate Forcing ◽  
Glacier Change ◽  
Outlet Glacier ◽  
Ice Cap ◽  
Digital Terrain ◽  
Terrain Models ◽  
Glacier Changes ◽  
The Mean ◽  
Temperature Offset ◽  
Mean Annual Air Temperature

AbstractDigital terrain models of the southern Chilean ice cap Gran Campo Nevado reflecting the terrain situations of the years 1984 and 2000 were compared in order to obtain the volumetric glacier changes that had occurred during this period. The result shows a slightly negative mean glacier change of 3.80 m. The outlet glacier tongues show a massive thinning, whereas the centre of the ice cap is characterized by a moderate thickening. Thus a distinct altitudinal variability of the glacier change is noticed. Hypothetically this could be explained by the combined effects of increased precipitation and increased mean annual air temperature. Both to verify and to quantify this pattern of climatic change, the mean glacier change as well as its hypsometric variation are compared with the results of a degree-day model. The observed volumetric glacier change is traced back to possible climate forcing and can be linked to an underlying climate change that must be comparable with the effects of a precipitation offset of at least 7–8% and a temperature offset of around 0.3 K compared to the steady-state conditions in the period 1984–2000.

scholarly journals Estimated Land and Building Tax using Aerial Photography (Case Study: Tingkir District, Salatiga City)

2020 ◽  
Vol 4 (2) ◽  
pp. 372-378
Author(s):  
Josef Allen ◽  
Frederik Samuel Papilaya
Keyword(s):  
Aerial Photographs ◽  
Digital Terrain Models ◽  
Raster Calculator ◽  
Digital Terrain ◽  
Terrain Models ◽  
Surface Models ◽  
Building Area ◽  
The City ◽  
Area Data

Salatiga, a city that borders directly and is surrounded by Semarang Regency. It has an area of ​​56.78 km2, with four sub-districts including, Sidorejo Regency, Argomulyo Regency, Tingkir Regency, and Sidomukti Regency, which covers 23 villages. The city of Salatiga has a fairly high population density with a proportion of more than 3300 inhabitants / km2. In this study took place in the Central Tingkir and Tingkir Lor areas by taking several points that are considered as housing as a case study. This study aims to estimate the price of land and building tax on an object of land and building tax. The process of this research uses aerial photo processing, where aerial photographs will be processed using professional software Agisoft photoscan to become an orthophoto, digital surface models and digital terrain models to obtain building area and land area data, then digital surface models and digital terrain models are processed . with ArcGIS 10.6 software using a raster calculator to get the height of the object to be used as the height of the building. The data obtained will be used to perform land and building tax calculations. The results of this study estimate the estimated land and building tax prices of at least IDR 37,313.00 and a maximum value of IDR 3,809,763.00.  

scholarly journals Landsat-derived glacier inventory for Jotunheimen, Norway, and deduced glacier changes since the 1930s

2008 ◽  
Vol 2 (2) ◽  
pp. 131-145 ◽  
Author(s):  
L. M. Andreassen ◽  
F. Paul ◽  
A. Kääb ◽  
J. E. Hausberg
Keyword(s):  
Mapping Method ◽  
Aerial Photographs ◽  
Glacier Inventory ◽  
Digital Maps ◽  
Area Reduction ◽  
Glacier Recession ◽  
Glacier Changes ◽  
Automatic Mapping ◽  
The 1960S ◽  
And Control

Abstract. A Landsat Thematic Mapper (TM) scene from 2003 covering the Jotunheimen and Breheimen region has been used to map the recent glacier extents using thresholded ratio images (TM3/TM5). Orthoprojected aerial photographs and glacier outlines from digital maps have been used to validate the method and control the results. We further calculated glacier changes by comparing the Landsat-derived 2003 glacier outlines with previous maps and inventories from the 1930s, 1960s and 1980s. Our results confirm that the applied automatic mapping method is robust and agrees with the reference data used. Some manual editing was necessary to correct the outline at ice-lake contacts and at debris covered glaciers. However, for most of the glaciers no corrections were required. The most laborious task has been to assign ID numbers and couple the new Landsat inventory to previous inventories to assess area changes. The glaciers investigated shrank since the 1930s with an overall area reduction of about 23% for 38 glaciers. Since the 1960s the area reduction was 12% for 164 glaciers. Although the general trend is glacier recession, some glaciers have increased their size or remained nearly unchanged over these decades.

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