Digital Topography Research Articles

A novel topographic parameterization scheme indicates that martian gullies display the signature of liquid water

Martian gullies resemble gullies carved by water on Earth, yet are thought to have formed in an extremely cold (<−50°C) and dry (humidity <100 precipitable micrometers) surface environment (cf. Mellon et al., 2004). Despite more than a decade of observations, no consensus has emerged as to whether liquid water is required to form martian gullies, with some recent studies favouring dry CO2-driven processes. That this argument persists demonstrates the limitations of morphological interpretations made from 2D images, especially when similar-looking landforms can form by very different processes. To overcome this we have devised a parameterization scheme, based on statistical discriminant analysis and hydrological terrain analysis of meter-scale digital topography data, which can distinguish between dry and wet surface processes acting on a landscape. Applying this approach to new meter-scale topographic datasets of Earth, the Moon and Mars, we demonstrate that martian gullied slopes are dissimilar to dry, gullied slopes on Earth and the Moon, but are similar to both terrestrial debris flows and fluvial gullies. We conclude that liquid water was integral to the process by which martian gullies formed. Finally, our work shows that quantitative 3D analyses of landscape have great potential as a tool in planetary science, enabling remote assessment of processes acting on planetary surfaces.

Anthropocene rockfalls travel farther than prehistoric predecessors.

Human modification of natural landscapes has influenced surface processes in many settings on Earth. Quantitative data comparing the distribution and behavior of geologic phenomena before and after human arrival are sparse but urgently required to evaluate possible anthropogenic influences on geologic hazards. We conduct field and imagery-based mapping, statistical analysis, and numerical modeling of rockfall boulders triggered by the fatal 2011 Christchurch earthquakes (n = 285) and newly identified prehistoric (Holocene and Pleistocene) boulders (n = 1049). Prehistoric and modern boulders are lithologically equivalent, derived from the same source cliff, and yield consistent power-law frequency-volume distributions. However, a significant population of modern boulders (n = 26) traveled farther downslope (>150 m) than their most-traveled prehistoric counterparts, causing extensive damage to residential dwellings at the foot of the hillslope. Replication of prehistoric boulder distributions using three-dimensional rigid-body numerical models that incorporate lidar-derived digital topography and realistic boulder trajectories and volumes requires the application of a drag coefficient, attributed to moderate to dense slope vegetation, to account for their spatial distribution. Incorporating a spatially variable native forest into the models successfully predicts prehistoric rockfall distributions. Radiocarbon dating provides evidence for 17th to early 20th century deforestation at the study site during Polynesian and European colonization and after emplacement of prehistoric rockfall. Anthropocene deforestation enabled modern rockfalls to exceed the limits of their prehistoric predecessors, highlighting a shift in the geologic expression of rockfalls due to anthropogenic activity. Reforestation of hillslopes by mature native vegetation could help reduce future rockfall hazard.

Morphotectonic map generation using geo-informatics technology: case study over the Ajay-Damodar Interfluve, West Bengal, INDIA

The morphotectonic index mapping is a key method to know the continuous interplay between sub-surface geotectonic and surface geomorphic processes. An integrated approach with fluvial geomorphology, morphotectonic, digital topography, satellite imageries and field mapping aids to represent the surficial tectonic sensitivity of the Ajay-Damodar Interfluve (ADI) region. Seven morphotectonic indices, such as Isobase Map, Hydraulic Gradient Map, Transverse Topographic Symmetry Factor or T-index, Regional Sinuosity Index, Flow Turn Angle and Structural Lineament Density, have been compiled here using geo-informatics technology. Regional Bouguer gravity anomaly data have also been compared with the obtained result. Neotectonic nomenclature is more prominent over the eastern Quaternary sedimentary lowland than western super groups of Gondwana formation and lateritic patches. The role of tectonic control on the drainage system is reflected by distinct drainage patterns, abrupt changes in flow direction, offset river channels, straight river lines, ponded river channel, marshy lands, sag ponds, palaeochannels, alluvial fans, meander cutoffs, multi-terrace river valley, incised compressed meander and convexity or knick points in longitudinal profiles.

Mt. Etna volcano high-resolution topography: airborne LiDAR modelling validated by GPS data

ABSTRACTHigh-resolution digital topography is essential for land management and planning in any type of territory as well as the reproduction of the Earth surface in a geocoded digital format that allows several Digital Earth applications. In a volcanic environment, Digital Elevation Models are a valid reference for multi-temporal analyses aimed to observe frequent changes of a volcano edifice and for the relative detailed morphological and structural analyses. For the first time, a DTM (Digital Terrain Model) and a DSM (Digital Surface Model) covering the entire Mt. Etna volcano (Italy) derived from the same airborne Light Detection and Ranging (LiDAR) are here presented. More than 250 million 3D LiDAR points have been processed to distinguish ground elements from natural and anthropic features. The end product is the highly accurate representation of Mt. Etna landscape (DSM) and ground topography (DTM) dated 2005. Both models have a high spatial resolution of 2 m and cover an area of 620 km2. The DTM has been validated by GPS ground control points. The vertical accuracy has been evaluated, resulting in a root-mean-square-error of ± 0.24 m. The DTM is available as electronic supplement and represents a valid support for various scientific studies.

Emplacement conditions of the 1256 AD Al-Madinah lava flow field in Harrat Rahat, Kingdom of Saudi Arabia — Insights from surface morphology and lava flow simulations

Lava flow hazard modelling requires detailed geological mapping, and a good understanding of emplacement settings and the processes involved in the formation of lava flows. Harrat Rahat, Kingdom of Saudi Arabia, is a large volcanic field, comprising about 1000 predominantly small-volume volcanoes most of which have emitted lava flows of various lengths. A few eruptions took place in this area during the Holocene, and they were located in the northern extreme of the Harrat Rahat, a close proximity to critical infrastructure and population living in Al-Madinah City. In the present study, we combined field work, high resolution digital topography and morphometric analysis to infer the emplacement history of the last historical event in the region represented by the 1256AD Al-Madinah lava flow field. These data were also used to simulate 1256AD-type lava flows in the Harrat Rahat by the MAGFLOW lava flow emplacement model, which is able to relate the flow evolution to eruption conditions. The 1256AD lava flow field extent was mapped at a scale of 1:1000 from a high resolution (0.5m) Light Detection And Ranging (LiDAR) Digital Terrain Model (DTM), aerial photos with field support. The bulk volume of the lava flow field was estimated at 0.4km3, while the source volume represented by seven scoria cone was estimated at 0.023km3. The lava flow covered an area of 60km2 and reached a maximum length of 23.4km. The lava flow field comprises about 20.9% of pāhoehoe, 73.8% of 'a'ā, and 5.3% of late-stage outbreaks. Our field observation, also suggests that the lava flows of the Harrat Rahat region are mainly core-dominated and that they formed large lava flow fields by amalgamation of many single channels. These channels mitigated downslope by topography-lava flow and channel–channel interactions, highlighting this typical process that needs to be considered in the volcanic hazard assessment in the region. A series of numerical lava flow simulations was carried out using a range of water content (0.1–1wt.%), solidification temperature (800–600°C) and effusion curves (simple and complex curves). These simulations revealed that the MAGFLOW code is sensitive to the changes of water content of the erupting lava magma, while it is less sensitive to solidification temperature and the changes of the shape of effusion curve. The advance rate of the simulated lava flows changed from 0.01 to 0.22km/h. Using data and observations from the youngest volcanic event of the Harrat Rahat as input parameters to MAGFLOW code, it is possible to provide quantitative limits on this type of hazard.

Drainage reorganization during mountain building in the river system of the Eastern Cordillera of the Colombian Andes

The Eastern Cordillera of Colombia is a thick-skinned thrust-fold belt that is characterized by two topographic domains: (1) the axial zone, a high altitude plateau (the Sabana de Bogotá, 2500masl) with low local relief and dominated by longitudinal rivers, and (2) the Cordillera flanks, where local relief exceeds 1000m and transverse rivers dominate. On the basis of an analysis of digital topography and river parameters combined with a review of paleodrainage data, we show that the accumulation of shortening and crustal thickening during the Andean orogeny triggered a process of fluvial reorganization in the Cordillera. Owing to a progressive increase of the regional slope, the drainage network evolves from longitudinal to transverse-dominated, a process that is still active at present. This study provides the idea of progressive divide migration toward the inner part of the mountain belt, by which the area of the Sabana de Bogotá plateau is decreasing, the flanks increase in area, and ultimately transverse rivers will probably dominate the drainage of the Cordillera.

High-resolution gravity and geoid models in Tahiti obtained from new airborne and land gravity observations: data fusion by spectral combination

Abstract For the first time, we carry out an airborne gravity survey and we collect new land gravity data over the islands of Tahiti and Moorea in French Polynesia located in the South Pacific Ocean. The new land gravity data are registered with GPS-derived coordinates, network-adjusted and outlier-edited, resulting in a mean standard error of 17 μGal. A crossover analysis of the airborne gravity data indicates a mean gravity accuracy of 1.7 mGal. New marine gravity around the two islands is derived from Geosat/GM, ERS-1/GM, Jason-1/GM, and Cryosat-2 altimeter data. A new 1-s digital topography model is constructed and is used to compute the topographic gravitational effects. To use EGM08 over Tahiti and Moorea, the optimal degree of spherical harmonic expansion is 1500. The fusion of the gravity datasets is made by the band-limited least-squares collocation, which best integrates datasets of different accuracies and spatial resolutions. The new high-resolution gravity and geoid grids are constructed on a 9-s grid. Assessments of the grids by measurements of ground gravity and geometric geoidal height result in RMS differences of 0.9 mGal and 0.4 cm, respectively. The geoid model allows 1-cm orthometric height determination by GPS and Lidar and yields a consistent height datum for Tahiti and Moorea. The new Bouguer anomalies show gravity highs and lows in the centers and land-sea zones of the two islands, allowing further studies of the density structure and volcanism in the region.

VolcFlow capabilities and potential development for the simulation of lava flows

Abstract VolcFlow is a finite-difference Eulerian code based on the depth-averaged approach and developed for the simulation of isothermal geophysical flows. Its capability for reproducing lava flows is tested here for the first time. The field example chosen is the 2010 lava flow of Tungurahua volcano (Ecuador), the emplacement of which is tracked by projecting thermal images onto a georeferenced digital topography. Results show that, at least for this case study, the isothermal approach of VolcFlow is able to simulate the velocity of the lava through time, as well as the extent of the solidified lava. However, the good fit between the modelled and the natural flow may be explained by the short emplacement time ( c. 20 h) of a thick lava ( c. 5 m), which could limit the influence of cooling on the flow dynamics, thus favouring the use of an isothermal rheology.

Quaternary tectonic control on channel morphology over sedimentary low land: A case study in the Ajay-Damodar interfluve of Eastern India

The style of active tectonic on the deformation and characterization of fluvial landscape has been investigated on three typical skrike-slip fault zones of the Ajay-Damodar Interfluve (ADI) in Eastern India through field mapping, structural analysis and examination of digital topography (ASTER-30 m), multi-spectral imageries, and Google Earth images. Channel morphology in Quaternary sediment is more deformed than Cenozoic lateritic tract and igneous rock system by the neotectonic activities. The structural and lithological controls on the river system in ADI region are reflected by distinct drainage patterns, abrupt change in flow direction, offset river channels, straight river lines, ponded river channel, marshy lands, sag ponds, palaeo-channels, alluvial fans, meander cutoffs, multi-terrace river valley, incised compressed meander, convexity of channel bed slope and knick points in longitudinal profile. Seven morphotectonic indices have been used to infer the role of neotectonic on the modification of channel morphology. A tectonic index map for the ADI region has been prepared by the integration of used morphotectonic indices, which is also calibrated by Bouguer gravity anomaly data and field investigation.

Flow of Antarctic Bottom Water at the output of the Vema Channel

The pathways of the coldest part of the Antarctic Bottom Water (AABW) with potential temperature θ < 0.0°C in the Vema Channel and the pathways of this water flowing out of the channel to the Brazil Basin are studied on the basis of the data collected during the Russian expeditions in 2003, 2009–2012, and historical CTD data. It is shown that the AABW flows to the north in the Vema Channel as two streams, one of which is located in the deep channel and the other approximately 300 m higher over the western slope of the channel. It was found that the northern end of the deep channel is not located near 26°40′ S, 34°00′ W as a widening in the northern direction to the Brazil Basin as follows from the dataset of digital topography (Smith and Sandwell, 1997) but continues in the eastern direction. A weaker northerly flow of the cold AABW was also found from the results of the measurements in 2012, which is confined to a branch of the Vema Channel continuation.

Preparing a landslide and shadow inventory map from high-spatial-resolution imagery facilitated by an expert system

An expert system was developed to integrate all useful spatial information and help the interpreters determine the landslide and shaded areas quickly and accurately. The intersection of two spectral indices, namely the normalized difference vegetation index and the normalized green red difference index, as well as the first principle component of the panchromatic band, is employed to automatically determine the regional thresholds of nonvegetation and dark areas. These boundaries are overlaid on the locally enhanced image and the digital topography model to closely inspect each area with a preferred viewing direction. The other geospatial information can be switched on and off to facilitate interpretation. This new approach is tested with 2 m pan-sharpened multispectral imagery from Formosat-2 taken on August 24, 2009, for several disaster areas of Typhoon Morakot. The generated inventory of landslide and shadow areas is validated with the one manually delineated from the 25 cm aerial photos taken on the same day. The production, user, and overall accuracies are higher than 82%, 85%, and 98%, respectively. The fall in production and user accuracies mainly comes from the differences in resolution. This new approach is as accurate as the general approach of manual delineation and visual interpretation, yet significantly reduces the required time.

Semi-Global Matching of Pléiades Tri-Stereo Imagery to Generate Detailed Digital Topography for High-Alpine Regions

Nowadays, several sensors are capable of acquiring very high resolution (VHR) satellite images in stereo, and even in tri-stereo mode. These data can be efficiently exploited with photogrammetric methods, such as semi-global matching (SGM), to produce high quality 2.5D digital terrain information. Regarding the production of digital terrain models, since VHR (tri-)stereo satellite images are available at high temporal frequencies for nearly the whole globe, they can be considered an attractive alternative to restricted and expensive airborne laserscanning (ALS) data. In this study, SGM is applied to a Pléiades-1A image triplet, to generate an accurate and detailed 3D point cloud and a 2.5D digital surface model (DSM) for a high-alpine study area in South Tyrol with complex, snow- and ice-covered topography. Visual and quantitative comparison to an ALS reference DSM showed that there were only small elevation errors for large parts of the study area. Errors were higher in regions that were obscured by shade. This is one of the first studies demonstrating that SGM is not only capable of delivering reliable digital surface information for flat and hilly regions, but also for high-alpine areas with complex terrain.

Extracting ore-deposit-controlling structures from aeromagnetic, gravimetric, topographic, and regional geologic data in western Yukon and eastern Alaska

Aeromagnetic lineaments interpreted from reduced-to-pole (RTP) magnetic grids were compared with gravity, topography, and field-based geologic maps to infer regional structural controls on hydrothermal mineral occurrences in a poorly exposed portion of the North American Cordillera in western Yukon and eastern Alaska. High-frequency and variable-intensity aeromagnetic lineaments corresponding to discontinuities with an aeromagnetic domain change were interpreted as steep-dipping and either magnetite-destructive or magnetite-additive faults. These structures were interpreted to be predominantly Cretaceous in age and to have formed after the collision of the Intermontane terranes with the ancient Pacific margin of North America. To demonstrate the reliability of the aeromagnetic interpretation, we developed a multidata set stacking methodology that assigns numeric values to individual lineaments depending on whether they can be traced in residuals and first vertical derivative of RTP aeromagnetic grids, isostatic residual gravity grids, digital topography, and regional geologic maps. The sum of all numeric values was used to estimate the likelihood of the aeromagnetic lineament as a true geologic fault. Fault systems were interpreted from zones of lineaments with high spatial density. Using this procedure, 10 major northwest-trending fault systems were recognized. These were oriented subparallel to the regional Cordilleran deformation fabric, the mid-Cretaceous Dawson Range magmatic arc, and well-established crustal-scale dextral strike-slip fault systems in the area. These orogen-parallel fault systems were interpreted to play a structural role in the emplacement of known porphyry Cu-Au and epithermal Au systems of mid-Cretaceous (115–98 Ma) and Late Cretaceous (79–72 Ma) age. The procedure also identified seven northeast-trending, orogen-perpendicular fault-fracture systems that are prominent in eastern Alaska and exhibit sinistral-to-oblique extensional kinematics. These structures were interpreted to govern the emplacement of Late Cretaceous (72–67 Ma) porphyry Mo- and Ag-rich polymetallic vein and carbonate replacement systems in the region.

Effects of terrain-induced shade removal using global DEM data sets on land-cover classification

Free access to global data sets of satellite images and digital elevation models (DEMs) such as Aster Global DEM (GDEM) and Shuttle Radar Topography Mission (SRTM) digital topography are expected to contribute to various study areas that deal with land cover and land use. To assess the capabilities of these global DEM data sets and to provide guidelines for performing shade removal under various terrain and illumination conditions, we evaluated the results of shade removal using the Minnaert correction and C-correction. These corrections were applied, using the GDEM (versions 1 and 2), SRTM, and a DEM derived from a local map (local DEM), to 30 sample images from 20 scenes of 10 path-rows in global land survey (GLS) Landsat-TM/ETM+ images, in terms of statistical indices and the accuracy of land-cover discrimination. The analysis indicated that the results of shade removal depended mainly on the correlation between the cosine of the sunshine incidence angle (cos(i)) and the radiance before shade removal, except in some cases with inferior illumination conditions. Of the three global DEMs, GDEM version 2 had the highest performance in shade removal. However, this study also indicated that successful shade removal was only one of the several factors that increased the accuracy of land-cover classification. In practical applications, shade removal can be recommended only for images where the terrain shade obviously disturbs the original spectral reflection characteristics of each land-cover type and no significant dependence of the land-cover distribution on the slope aspect is assumed. In such cases, also global DEMs evaluated in this study can be used for shade removal.

Crystal distortion of monoclinic hen egg-white lysozyme crystals using X-ray digital topography

The crystal distortion of monoclinic hen egg-white lysozyme (HEWL) crystals was observed by the X-ray digital topography. The local rocking curves were obtained by the series of the topographic images. The single, double, triple, and multiple peaks of the local rocking curves were observed. The mapping of the full width of the one tenth maximum (FW10M) of the local rocking curves was obtained. It was found that the magnitude of FW10M depended on the distance of the peak splitting. The distribution of the distortion in the monoclinic HEWL crystals was investigated by the analysis of the local rocking curves.

Redefining the watershed line and stream networks via digital resources and topographic map using GIS and remote sensing (case study: the Neka River’s watershed)

The accurate delineation of area plays a key role in the surveying of land change detection and the classification of land covers. In a hydrologic system, the watershed delineation and the detection of the boundaries among watershed is a basic method for performing spatial analyses. After recent advances in image processing and raster-based spatial analysis in geographic information systems, and being easily accessible data via various sources especially through remote sensing, the reliable determination of topographical boundaries possible is possible. Therefore, an integrated approach of data analysis and modeling can accomplish the task of delineation. The main aim in this research is to evaluate the delineation method of watershed boundary using four different digital elevation models (DEM) including advanced spaceborne thermal emission and reflection radiometer (ASTER), Shuttle Radar Topographic Mission (SRTM), digital topography, and topographic maps. In order to determine a true reference of boundary of watershed, sample data were also obtained by field survey and using global positioning system (GPS). The comparison reference points and the results of these data showed the average distance difference between reference boundary, and the result of ASTER data was 43 m. However, the average distance between GPS reference and the other data was high; the difference between the reference data and SRTM was 307 m, and for digital topographic map, it was 269 m. The average distance between topographic map and the GPS points differed 304 m as well. For the statistical analysis of comparison, the coordinates of 230 points were determined; the paired comparisons were also performed to measure the coefficient of determination, R 2, as well as analysis of variance in SPSS software. As a result, the R 2 values for the ASTER data with the digital topography and topographic map were 0.0157 and 0.171, respectively. The results showed that there were statistically significant differences in distances among the four means of the selected models. Therefore, considering other three methods, the ASTER DEM is the most suitable applicable data to delineate the borders of watersheds, especially in rugged terrains. In addition, the calculated flow directions of stream based on ASTER are close to natural tributaries as well as real positions of streams.

How lava flows: New insights from applications of lidar technologies to lava flow studies

Mafic lava flows are common; for this reason, they have long been a focus of volcanological studies. However, field studies of both older and active flows have been hampered by difficulties in field access; active flows are hot, whereas older flows have rough and jagged surfaces that are difficult to traverse. As a result, morphometric studies of lava flows have generally lagged behind theoretical studies of flow behavior. The advent of laser scanning (LS) (i.e., lidar, light detection and ranging) technologies, both airborne mapping (ALSM) and terrestrial (TLS), is promoting detailed studies of lava flows by generating data suitable for production of high-resolution digital elevation models (DEMs). These data are revolutionizing both the visual and quantitative analysis of lava flows. First and foremost, this technology allows accurate mapping of flow boundaries, particularly in vegetated areas where bare earth imaging dramatically improves mapping capabilities. Detailed imaging of flow surfaces permits mapping and measurement of flow components, such as channels, surface folds, cracks, blocks, and surface roughness. Differencing of preeruptive and posteruptive DEMs allows analysis of flow thickness variations, which can be related to the dynamics of lava emplacement. Multitemporal imaging of active flows provides information not only on the rates and locations of individual flow lobes, but also measurement of pulsed lava transport. Together these new measurement capabilities can be used to test proposed models of channel formation, lava tube formation, rates of flow advance, and flow conditions within lava channels; they also provide new ways to assess the hazard and risk posed by lava flow inundation. Early published studies illustrate the potential of applying lidar to volcanic terrain; it is clear, however, that the availability of high-resolution digital topography is poised to revolutionize the study of mafic lava flows.

Morphotectonic analysis of the Lunigiana and Garfagnana grabens (northern Apennines, Italy): Implications for active normal faulting

This work integrates existing structural geology data with new detailed geomorphic analyses of the fluvial network to characterize active and potentially seismogenic faults bordering the Lunigiana and Garfagnana basins in the northern Apennines of Italy. These two basins are NW–SE-oriented asymmetric grabens, bordered by several normal faults with a poorly known, but probable recent slip history. Several strong earthquakes (M 5.0–6.5) have occurred in the area in the last millennium, demonstrating that this is one of the most seismically active areas of the northern Apennines. However, the lack of reliable instrumental data for strong earthquakes, generally low deformation rates, and poor exposures of faulted Quaternary sediments render the characterization of active, seismogenic faults problematic.Here, we quantify the relationships between faults and watershed-scale geomorphology using 10-m digital topography to extract channel and basin metrics, such as steepness, concavity, and stream length-gradient indices of modeled river longitudinal profiles. In particular, convex segments of longitudinal profiles (knickpoints) are investigated in the spatial context of suspected active faults. Several knickpoints arise locally from juxtaposed rock types of different erodibility; however, many others mapped along major normal faults have a clear tectonic origin. In fact, the height of the footwall knickpoints (the closest to the fault trace) varies along-strike the fault, increasing toward the fault center and tapering off toward the fault tips, mimicking the expected displacement profile of a fault. In these cases, we consider the knickpoint height as a proxy of the fault throw accumulated by the youngest fault activity, probably during the late Quaternary. The along-strike distribution of knickpoint heights helps in defining the likely segmentation pattern of the fault system. The identified active normal fault segments have lengths ranging from 9.5 to 28.5km. The inferred late Quaternary throw rate ranges from 0.3 to 0.8mm/a; however, the absence of any offset datable material limits our ability to assign precise numeric ages and rates of offset to the faulting.

Tectonic Geomorphology, Second Edition

Book Review| May 01, 2013 Tectonic Geomorphology, Second Edition Douglas W. Burbank; Douglas W. Burbank Smith Geologic and Photographic Services, LLC, 13786 Schoger Road, Nathrop, CO 81236 Search for other works by this author on: GSW Google Scholar Robert S. Anderson Robert S. Anderson Smith Geologic and Photographic Services, LLC, 13786 Schoger Road, Nathrop, CO 81236 Search for other works by this author on: GSW Google Scholar Author and Article Information Douglas W. Burbank Smith Geologic and Photographic Services, LLC, 13786 Schoger Road, Nathrop, CO 81236 Robert S. Anderson Smith Geologic and Photographic Services, LLC, 13786 Schoger Road, Nathrop, CO 81236 Publisher: Association of Environmental & Engineering Geologists First Online: 02 Mar 2017 Online Issn: 1558-9161 Print Issn: 1078-7275 © 2013 Association of Environmental & Engineering Geologists Environmental & Engineering Geoscience (2013) 19 (2): 198–200. https://doi.org/10.2113/gseegeosci.19.2.198 Article history First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Douglas W. Burbank, Robert S. Anderson; Tectonic Geomorphology, Second Edition. Environmental & Engineering Geoscience 2013;; 19 (2): 198–200. doi: https://doi.org/10.2113/gseegeosci.19.2.198 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Review by: Richard P. Smith This second edition of Tectonic Geomorphology (Burbank and Anderson, 2012) is written only a little more than a decade after the first edition, but the changes are substantial: 500 new references, most published in the last decade, and 150 new illustrations have been added. Many recent advances and developments encouraged the writing of the new edition: increased availability of digital topography and Earth imagery (Google Earth, for example), widespread application of light detection and ranging (LiDAR) mapping, more refined techniques of measuring Earth deformation (interferometric synthetic aperture radar [InSAR], continuous global positioning system... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Soil prediction using artificial neural networks and topographic attributes

Because relief maps show a strict relationship with soils at different spatial levels, distributions of soil units can be inferred from digital topography analyses. Geoprocessing techniques can be used to create parametric relief representations from digital terrain models (DTMs), and these models can be used to calculate primary and secondary topographical attributes, such as the elevation, profile and plan curvature, slope, stream power index, topographic wetness index, and sediment transport index. The classic method of pedological cartography is onerous and time-consuming; as an alternative, pedometric techniques favor the recognition of preliminary mapping units. In this study, a multilayered perceptron artificial neural network (ANN) with an error backpropagation algorithm was used, where topographical and geological attributes were used as input parameters. The classified map was validated by comparison with two preexisting conventional ground maps of the study area. The kappa (K) index, global exactness (GE), and exactness from the point of view of the producer and user were considered in the comparison. The quality of the soil units classified by the ANN was satisfactory, based on the K and GE values from the comparison.