scholarly journals The Geomorphology, Structure, and Lava Flow Dynamics of Peralkaline Rift Volcanoes From High‐Resolution Digital Elevation Models

2019 ◽  
Vol 20 (3) ◽  
pp. 1508-1538 ◽  
Author(s):  
Jonathan A. Hunt ◽  
David M. Pyle ◽  
Tamsin A. Mather
Keyword(s):  
High Resolution ◽  
Lava Flow ◽  
Digital Elevation Models ◽  
Flow Dynamics ◽  
Digital Elevation

scholarly journals Glacier elevation and mass changes over the central Karakoram region estimated from TanDEM-X and SRTM/X-SAR digital elevation models

2016 ◽  
Vol 57 (71) ◽  
pp. 273-281 ◽  
Author(s):  
Melanie Rankl ◽  
Matthias Braun
Keyword(s):  
High Resolution ◽  
Snow Cover ◽  
Digital Elevation Models ◽  
Mass Balances ◽  
Freshwater Resources ◽  
Digital Elevation ◽  
Glacier Changes ◽  
Kinematic Waves ◽  
Elevation Changes ◽  
River Communities

AbstractSnow cover and glaciers in the Karakoram region are important freshwater resources for many down-river communities as they provide water for irrigation and hydropower. A better understanding of current glacier changes is hence an important informational baseline. We present glacier elevation changes in the central Karakoram region using TanDEM-X and SRTM/X-SAR DEM differences between 2000 and 2012. We calculated elevation differences for glaciers with advancing and stable termini or surge-type glaciers separately using an inventory from a previous study. Glaciers with stable and advancing termini since the 1970s showed nearly balanced elevation changes of -0.09 ±0.12 m a-1 on average or mass budgets of -0.01 ±0.02Gt a-1 (using a density of 850 kg m-3). Our findings are in accordance with previous studies indicating stable or only slightly negative glacier mass balances during recent years in the Karakoram. The high-resolution elevation changes revealed distinct patterns of mass relocation at glacier surfaces during active surge cycles. The formation of kinematic waves at quiescent surge-type glaciers could be observed and points towards future active surge behaviour. Our study reveals the potential of the TanDEM-X mission to estimate geodetic glacier mass balances, but also points to still existing uncertainties induced by the geodetic method.

scholarly journals Scoria cones on Mars: Detailed investigation of morphometry based on high-resolution digital elevation models

2015 ◽  
Vol 120 (9) ◽  
pp. 1512-1527 ◽  
Author(s):  
Petr Brož ◽  
Ondřej Čadek ◽  
Ernst Hauber ◽  
Angelo Pio Rossi
Keyword(s):  
High Resolution ◽  
Digital Elevation Models ◽  
Digital Elevation ◽  
Scoria Cones

scholarly journals The use of LIDAR as a data source for digital elevation models – a study of the relationship between the accuracy of digital elevation models and topographical attributes in northern peatlands

2011 ◽  
Vol 8 (3) ◽  
pp. 5497-5522 ◽  
Author(s):  
A. Hasan ◽  
P. Pilesjö ◽  
A. Persson
Keyword(s):  
High Resolution ◽  
Interpolation Method ◽  
Digital Elevation Models ◽  
Drainage Area ◽  
Absolute Deviation ◽  
Weighting Method ◽  
Dem Resolution ◽  
Coarse Resolution ◽  
Digital Elevation ◽  
Topographical Attributes

Abstract. It is important to study the factors affecting estimates of wetness since wetness is crucial in climate change studies. The availability of digital elevation models (DEMs) generated with high resolution data is increasing, and their use is expanding. LIDAR earth elevation data have been used to create several DEMs with different resolutions, using various interpolation parameters, in order to compare the models with collected surface data. The aim is to study the accuracy of DEMs in relation to topographical attributes such as slope and drainage area, which are normally used to estimate the wetness in terms of topographic wetness indices. Evaluation points were chosen from the high-resolution LIDAR dataset at a maximum distance of 10 mm from the cell center for each DEM resolution studied, 0.5, 1, 5, 10, 30 and 90 m. The interpolation method used was inverse distance weighting method with four search radii: 1, 2, 5 and 10 m. The DEM was evaluated using a quantile-quantile test and the normalized median absolute deviation. The accuracy of the estimated elevation for different slopes was tested using the DEM with 0.5 m resolution. Drainage areas were investigated at three resolutions, with coinciding evaluation points. The ability of the model to generate the drainage area at each resolution was obtained by pairwise comparison of three data subsets. The results show that the accuracy of the elevations obtained with the DEM model are the same for different resolutions, but vary with search radius. The accuracy of the values (NMAD of errors) varies from 29.7 mm to 88.9 mm, being higher for flatter areas. It was also found that the accuracy of the drainage area is highly dependent on DEM resolution. Coarse resolution yielded larger estimates of the drainage area but lower slope values. This may lead to overestimation of wetness values when using a coarse resolution DEM.

scholarly journals Bag of Geomorphological Words: A Framework for Integrating Terrain Features and Semantics to Support Landform Object Recognition from High-Resolution Digital Elevation Models

2020 ◽  
Vol 9 (11) ◽  
pp. 620
Author(s):  
Xiran Zhou ◽  
Xiao Xie ◽  
Yong Xue ◽  
Bing Xue ◽  
Kai Qin ◽  
...  
Keyword(s):  
Object Recognition ◽  
High Resolution ◽  
Feature Vector ◽  
Dimensional Space ◽  
Digital Elevation Models ◽  
Three Dimensional ◽  
Slope Aspect ◽  
Digital Elevation ◽  
Great Possibility ◽  
High Level

High-resolution digital elevation models (DEMs) and its derivatives (e.g., curvature, slope, aspect) offer a great possibility of representing the details of Earth’s surface in three-dimensional space. Previous research investigations concerning geomorphological variables and region-level features alone cannot precisely characterize the main structure of landforms. However, these geomorphological variables are not sufficient to represent a complex landform object’s whole structure from a high-resolution DEM. Moreover, the amount of the DEM dataset is limited, including the landform object. Considering the challenges above, this paper reports an integrated model called the bag of geomorphological words (BoGW), enabling automatic landform recognition via integrating point and linear geomorphological variables, region-based features (e.g., shape, texture), and high-level landform descriptions. First, BoGW semantically characterizes the composition of geomorphological variables and meaningful parcels of each type of landform. Based on a landform’s semantics, the proposed method then integrates geomorphological variables and region-level features (e.g., shape, texture) to create the feature vector for the landform. Finally, BoGW classifies a region derived from high-resolution DEM into a predefined type of landform by the feature vector. The experimental results on crater and cirque detection indicated that the proposed BoGW could support landform object recognition from high-resolution DEMs.

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