Digital Terrain Analysis

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Case based knowledge formalization and reasoning method for digital terrain analysis – application to extracting drainage networks

Case based knowledge formalization and reasoning method for digital terrain analysis – application to extracting drainage networks

Abstract. Application of digital terrain analysis (DTA), which is typically a modeling process involving workflow building, relies heavily on DTA domain knowledge of the match between the algorithm (and its parameter settings) and the application context (including the target task, the terrain in the study area, the DEM resolution, etc.), which is re- ferred to as application-context knowledge. However, exist- ing DTA-assisted tools often cannot use application-context knowledge because this type of DTA knowledge has not been formalized to be available for inference in these tools. This situation makes the DTA workflow-building process difficult for users, especially non-expert users. This paper proposes a case-based formalization for DTA application- context knowledge and a corresponding case-based reason- ing method. A case in this context consists of a series of indices that formalize the DTA application-context knowl- edge and the corresponding similarity calculation methods for case-based reasoning. A preliminary experiment to de- termine the catchment area threshold for extracting drainage networks has been conducted to evaluate the performance of the proposed method. In the experiment, 124 cases of drainage network extraction (50 for evaluation and 74 for rea- soning) were prepared from peer-reviewed journal articles. Preliminary evaluation shows that the proposed case-based method is a suitable way to use DTA application-context
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Digital terrain analysis reveals new insights into the topographic context of Australian Aboriginal stone arrangements

Digital terrain analysis reveals new insights into the topographic context of Australian Aboriginal stone arrangements

ABSTRACT Satellite ‐ derived surface elevation models are an important resource for landscape archaeological studies. Digital elevation data is useful for classifying land features, characterizing terrain morphology, and discriminating the geomor- phic context of archaeological phenomena. This paper shows how remotely sensed elevation data obtained from the Japan Aerospace Exploration Agency ’ s Advanced Land Observing Satellite was integrated with local land system spa- tial data to digitally classify the topographic slope position of seven broad land classes. The motivation of our research was to employ an objective method that would allow researchers to geomorphometrically discriminate the topographic context of Aboriginal stone arrangements, an important archaeological site type in the Pilbara region of northwest Australia. The resulting digital terrain model demonstrates that stone arrangement sites are strongly correlated with upper topographic land features, a fi nding that contradicts previous site recordings and fundamentally changes our understanding of where stone arrangement sites are likely to have been constructed. The outcome of this research provides investigators with a stronger foundation for testing hypotheses and developing archaeological models. To some degree, our results also hint at the possible functions of stone arrangements, which have largely remained enigmatic to researchers. © 2017 The Authors. Archaeological Prospection Published by John Wiley & Sons Ltd.
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Filtering of digital terrain models by 2D Singular Spectrum Analysis

Filtering of digital terrain models by 2D Singular Spectrum Analysis

A surface can be viewed as a sum of surfaces. This triviality forms the basis to solve a variety of problems using digital terrain analysis. The best-known tasks follow: (1) separating topographic components of different scales; (2) denoising digital terrain models (DTMs); and (c) generalising DTMs, that is, removing non-noise high-frequency components from DTMs. These tasks are usually attacked by multiple regressions (Chorley and Huggett, 1965; Tobler, 1969), weighted moving averages (Tobler, 1969), Fourier analysis (Rudy, 1989), Kalman filtering (Gallant, 2006), and isobase mapping (Grohmann et al., 2007). In this paper, we report the first results of evaluation of two-dimensional Singular Spectrum Analysis (2D- SSA) as a tool to denoise and generalise DTMs and to separate continental, regional, and local components of topography.
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Earthquake Analysis of RCC Buildings on Hilly Terrain

Earthquake Analysis of RCC Buildings on Hilly Terrain

The models where analyzed and compared while considering displacement, story drift and base shear. It was observed that,. Step back-Set back buildings were found to be less vulnerable than Step back buildings against seismic ground motion on sloping ground. Hence, Step back-Set back buildings can be considered more favourable in hilly terrain areas than Step back buildings.

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A new method for determination of most likely landslide initiation points and the evaluation of digital terrain model scale in terrain stability mapping

A new method for determination of most likely landslide initiation points and the evaluation of digital terrain model scale in terrain stability mapping

In this paper we present a new method for determining the most likely landslide initiation points. This method is re- ferred to as MLIP. The method introduced identifies the grid cell with critical (lowest) stability index on each downslope path from ridge to valley. If a stability index threshold is specified the MLIP are a subset of the points with stability in- dex less than the threshold with the special property that they are flow path specific minima. This makes MLIP points bet- ter points to use in the evaluation of a terrain stability model when the observations being used to evaluate the model are not limited to initiation locations, but include run out and deposition areas. A stability index attempts to quantify the potential for landslide initiation. Evaluation of the effective- ness of a stability index is inhibited when observations do not separate initiation from run out and deposition areas. The use of MLIP avoids these problems and tabulation of the density of MLIP points inside and outside such mapped areas pro- vides a quantification of the effectiveness of a terrain stabil- ity model in terms of the density of points within the mapped landslide scar where landslides are most likely to have ini- tiated. The use of a threshold avoids identification of stable locations as MLIP on flow paths that do not contain any un- stable locations. We evaluate the benefits of this method and the sensitivity to varying the grid size resolution of the digi- tal terrain model used for mapping landslide areas with this method. The most likely landslide initiation point approach can be applied with any spatial index of terrain stability, em- pirically or physically derived. Here the most likely landslide initiation approach was applied using terrain slope as a sim- ple empirical measure of terrain stability. The most likely landslide initiation point approach was then also applied to a Stability Index field obtained from SINMAP using the de- fault parameters suggested by Pack et al. (1998). The SIN- MAP stability index is used as a convenient example for the development and evaluation of this method. Comparisons of the most likely landslide initiation point approach applied to SINMAP SI and to slope demonstrates how the most likely landslide initiation points can be used to compare two differ- ent terrain stability models.
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Study of the LiDAR accuracy in mapping forest road alignments and estimating the earthwork volume

Study of the LiDAR accuracy in mapping forest road alignments and estimating the earthwork volume

general, it is noticed that the differences in earth- work volume estimates between LiDAR and LTS become larger as terrain ruggedness and canopy density increases (Xiao et al. 2017). Previous stud- ies conducted by Contreras et al. (2012) also highlighted the importance of canopy cover den- sity and terrain ruggedness in improving the ac- curacy of earthwork volume calculation, which is consistent with our findings in this study. While LiDAR is able to record details in terrain varia- tions by using 1 m cross section spacing, these terrain details are ignored when 5 m cross section spacing are considered in LTS. In this study, it was proved that the road project can be prepared faster by LiDAR than that of LTS.
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Development of an automatic delineation of cliff top and toe on very irregular planform coastlines (CliffMetrics v1.0)

Development of an automatic delineation of cliff top and toe on very irregular planform coastlines (CliffMetrics v1.0)

The target cliff top and cliff toe locations are obtained from a cluster of 24 manually digitized lines from aerial photogra- phy. A group of 24 participants with a range of geological ex- pertise participated in the experiment, each interpreting data for three 1 km sections (FH1, FH2 and DG; see Fig. 2b, c). Using a geographic information system (GIS; Google Earth Pro 7.1.8.3036, 32-bit), participants attempted to delineate cliff top and toe lines without any prior knowledge of their location. As with the sensitivity analysis, we used a point- to-line metric to calculate the main statistics of the manu- ally digitized results. As a reference line, we generated a mean cliff top and toe line for each of the study sections from the participant data. We extracted the cliff top and toe points from each one of the manually digitized lines and cal- culated the average, standard deviation, maximum and mini-
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DIGITAL ELEVATION MODELS AND SLOPE ANALYSIS IN SOME PART OF PURNA RIVER SUBBASIN, CENTRAL INDIA

DIGITAL ELEVATION MODELS AND SLOPE ANALYSIS IN SOME PART OF PURNA RIVER SUBBASIN, CENTRAL INDIA

DEMs are used for visual analysis of topography, landscapes and landforms other than modeling of surface processes (Welch, 1990). Currently Digital elevation models (DEMs) is considered as the main resource for the extraction of various geomorphologic and topographic features depending on their elevation, spatial distribution and deviations (Felicisimo, 1994). Digital Elevation Model (DEM), Digital Elevation Data (DED), Digital Terrain Data (DTD) (Campbell, 2002) or Digital Terrain Model (DTM) all consists of different arrangements of individual points of x (east-west direction) and y (north-south direction) coordinates of horizontal geographic positions. Z is the vertical elevation value that is relative to a given datum for a set of x, y points (Bolstad , 1994, Welch, 1990). The satellite images are becoming useful and necessary in geomorphology, especially in obtaining quantitative measurements and performing geomorphic analyses (Hayden et al. 1986). Image analysis provide geologists an opportunity to enhance, manipulate, and combine remotely-sensed digital data with several types of geographic information that in turn increases the amount of extracted information related to topographic and geologic features (Horsby & Harris 1992). In the study area, how the IRS LISS III false colour composite and SRTM DEM has been used for deliation of the geomorphology of the upper Chandrabhaga River. It occupies an area of 308.29 km 2 . The elevation
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Vibration Analysis of an All-Terrain Vehicle

Vibration Analysis of an All-Terrain Vehicle

IJEDR1601043 International Journal of Engineering Development and Research (www.ijedr.org) 255 The excitation frequency of engine mount system is found to be 61.327 Hz. The engine use fo[r]

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Forest biomass change estimated from height change in interferometric SAR height models

Forest biomass change estimated from height change in interferometric SAR height models

Background: There is a need for new satellite remote sensing methods for monitoring tropical forest carbon stocks. Advanced RADAR instruments on board satellites can contribute with novel methods. RADARs can see through clouds, and furthermore, by applying stereo RADAR imaging we can measure forest height and its changes. Such height changes are related to carbon stock changes in the biomass. We here apply data from the current Tandem-X satellite mission, where two RADAR equipped satellites go in close formation providing stereo imaging. We combine that with similar data acquired with one of the space shuttles in the year 2000, i.e. the so- called SRTM mission. We derive height information from a RADAR image pair using a method called interferometry. Results: We demonstrate an approach for REDD based on interferometry data from a boreal forest in Norway. We fitted a model to the data where above-ground biomass in the forest increases with 15 t/ha for every m increase of the height of the RADAR echo. When the RADAR echo is at the ground the estimated biomass is zero, and when it is 20 m above the ground the estimated above-ground biomass is 300 t/ha. Using this model we obtained fairly accurate estimates of biomass changes from 2000 to 2011. For 200 m 2 plots we obtained an accuracy of 65 t/ha, which corresponds to 50% of the mean above-ground biomass value. We also demonstrate that this method can be applied without having accurate terrain heights and without having former in-situ biomass data, both of which are generally lacking in tropical countries. The gain in accuracy was marginal when we included such data in the estimation. Finally, we demonstrate that logging and other biomass changes can be accurately mapped. A biomass change map based on interferometry corresponded well to a very accurate map derived from repeated scanning with airborne laser.
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Design and Analysis of Gearbox of an All Terrain Vehicle

Design and Analysis of Gearbox of an All Terrain Vehicle

The agenda for designing gearbox was to increase the efficiency and torque of an ATV. The Gears were designed by using Gearcalc software and cad with the help of CatiaV5 and analysis was carried out by the software ‘Ansys’. Considering the efficiency of gears helical gears were selected. The speed and torque was selected optimum according to the event and thus gearbox of 2 stage single speed was designed and analyzed successfully.

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Numerical terrain modelling for wireless underground sensor networks: a protoype for nut tree plantations

Numerical terrain modelling for wireless underground sensor networks: a protoype for nut tree plantations

Abstract—Underground terrain poses a highly intricate and challenging environment to the propagation of waves carrying information from sensor to the sink nodes. Due to the complexity and level of detail, it is often difficult to realistically model such an environment for conducting tests. However, using numerical methods, the environment characteristics could be translated to a compatible framework, for testing complex networking models such as Wireless Underground Sensor Network (WUSN). Such transformation should lend the necessary clarity and simplicity required for effective problem analysis. In this paper, we demonstrate this possibility using the typical underground terrain environment for nut tree plantations, basing the field data on a full-fledged commercial pecan farm. The results shown are introductory to ongoing research on the effective use of such numerical methods for maximum power efficiency and bit rate for distributed WUSN, and optimum water usage in irrigation control. This paper forms a sequel to previous related research publications.
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Interpretation of Groundwater Flow into Fractured Aquifer

Interpretation of Groundwater Flow into Fractured Aquifer

A lineament is usually defined as a straight or curve lin- ear feature to be seen on the ground surface. Lineaments can be manmade structures such as roads and canals or geological structures such as faults/fractures, folds, and unconformities, differences in vegetation and soil mois- ture, or drainage networks (rivers). Lineaments can be mapped during a field survey, or by using air photos and remote sensing data either manually or by means of pat- tern recognition algorithms [6]. On contrary lineaments can be traced from remote sensed data or digital terrain models by mathematical algorithms.
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TERRAIN CLASSIFICATION FOR TRAVERSABILITY ANALYSIS FOR AUTONOMOUS ROBOT NAVIGATION IN UNKNOWN NATURAL TERRAIN

TERRAIN CLASSIFICATION FOR TRAVERSABILITY ANALYSIS FOR AUTONOMOUS ROBOT NAVIGATION IN UNKNOWN NATURAL TERRAIN

Texture analysis can also be efficiently utilized in the area of terrain classification. Dong Min et.al[15] used co- occurrence features with linear discriminate classifier and clustering algorithm based on artificial neural network for terrain classification especially for shadow, grass and road class. Texture classification itself is an image processing technique which is basically employees ed in computer vision applications, industrial automation and in content based image retrieval. Mathur P. et.al used textural gray level co-occurrence features with crisp rule based classifier to classify the terrain into several regions of navigable and not navigable area [16]
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Analysis of Digital Elevation Model and LNDSAT Data Using Geographic Information System for Soil Mapping in Urban Areas

Analysis of Digital Elevation Model and LNDSAT Data Using Geographic Information System for Soil Mapping in Urban Areas

DEM-ASTER (Advanced Spaceborne Thermal Emission and Reflection Ra- diometer) (resolution 30 m), obtained from the active sensor database ASTER GDEM v2 (version 2 of Global Digital Elevation Model), available for the entire globe, of the United States Geological Survey (USGS). The DEM-ASTER data has been used in conjunction with controlled OLI Data to provide a better visua- lization of the terrain in the study area. In addition, this 3D presentation of the landscape of study area is required to visualize the soil and relief elements rela- tionships, where the maps of the topographic features ( i.e . surface elevation, slope, aspect, shaded relief, convexity and soil moisture content) were generated using ArcGIS software. Accuracy of elevation data, number of analyses and ex- tent of spurious depressions of the DEM were compared, as suggested by [53], as well as the quality of the derived TAs. These TAs were chosen for being directly related to water movement in the soil, with an influence on the soil formation process [8] [16] [39].
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Design and Analysis of Frame of an All Terrain Vehicle

Design and Analysis of Frame of an All Terrain Vehicle

By considering the requirements for other subsystem assemblies like suspensions, steering, brakes, engine and transmission, frame is designed so that all the subassemblies could be connected together on the frame. The heavy parts like engine are directly mounted on the frame members. Lateral cross member are provided appropriately so as to counter any torsional force under running condition. 4.ANALYSIS PARAMETRS

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Unsupervised landslide risk dependent terrain segmentation on the basis of historical landslide data and geomorphometrical indicators.

Unsupervised landslide risk dependent terrain segmentation on the basis of historical landslide data and geomorphometrical indicators.

Nowadays, remote sensing data and image pro- cessing were used to the mapping of landslides and the determination of temporal associations between land- sliding events and surface conditions (Sangar and Kanungo 2004) while assessment of landslide suscep- tibility has been attempted in a wide variety of geo- graphic information systems using diverse approaches (Costanzo et al. 2014). These methods are based on the integration of combined effect of the spatial fac- tors identified to be important in assessing slope insta- bility. In these approaches, the spatial factors where integrated on an artificial regular-grid terrain-partition scheme (Shirzadi et al. 2017) that was not related to the geomorphologic entities that occur in the natural terrain.
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Erosion rate and previous extent of interior layered deposits on Mars revealed by obstructed landslides

Erosion rate and previous extent of interior layered deposits on Mars revealed by obstructed landslides

Identification of landslide diversion and obstruction in Ophir Chasma, Valles Marineris, Mars, including Mars Reconnaissance Orbiter Context Camera CTX images, digital terrain model DTM [r]

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Evaluating digital terrain indices for soil wetness mapping – a Swedish case study

Evaluating digital terrain indices for soil wetness mapping – a Swedish case study

The transect data for soil wetness were used to validate the digital terrain indices through direct point-by-point compar- isons (of each 2 m × 2 m cell). This was done using the mul- tivariate statistical program SIMCA-P + 12.0.1, Umetrics, Umeå. The statistical tests were done using the recently de- veloped orthogonal projections to latent structures method (OPLS; Eriksson et al., 2006a, b). This method, which is similar to principal component analysis, separates the vari- ations of the predictors (the DEM-derived soil wetness pre- dictors) into two parts: one part that is predictive of the field- determined soil wetness estimates and is plotted against the horizontal x axis (denoted “pq[1]”), and one part that is not and is plotted along the vertical y axis (the non-predictive axis, denoted “p o s o [1]”). In the resulting plot, the variables
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Digital Terrain Modeling Of The Buna River System And Of The Northwestern Flood Plain In Albania

Digital Terrain Modeling Of The Buna River System And Of The Northwestern Flood Plain In Albania

43 sheets of the scale 1:10 000, covering an area of about 80 km2, are scanned and georeferenced into Albanian coordinate system. The project team digitized carefully the existing contour lines and the spot heights, so the relevant DTM model embodies the accuracy of the original official topographic maps. This work enabled compilation of a solid digital database on the terrain, buildings and infrastructure objects, the watercourses and the existing drains, thus providing the necessary preconditions to analyze the existing drainage network and protection levees, as well as design of the new protection structures diverting storm waters from the flat plain to the sea.
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