delineation of biogeomorphic land units across a tropical natural and humanized terrain in los tuxtlas veracruz mexico abstract this paper analyzes landscape in a rainforest region integrating geomorphologic and ecosystem analysis methods major landscape elements geology geomorphology soils vegetation and land use were mapped as biogeomorphic land units using remote sensing and geographic information systems gis associations between these variables were analyzed by map fusion and the results were expressed on a land unit map scale ca 1 100 000 volcanic structures are dominant in the study area lava flows cover most of the region mainly as basalt several pyroclastic cones are widely distributed over the area but are dominant in the southeast region a hypsometric map derived from a digital elevation model dem and intersected with a land cover use map showed an altitudinal gradient of vegetation rainforest grows at lower altitudes 0 to 700 m and virola juglans and chionantus are distributed from 700 to 900 m these species are located on slopes of basalt and andesites intercalated with tephra recent isolated stratovolcano structures and an erosive flood plain at higher altitudes 900 to 1100 m the forest identified as chionantus ulmus randia is associated with cinder cones a quercus ulmus forest 900 to 1400 m covers the slopes of the highest volcano san martin and surrounding areas while evergreen elfin forest is at the top of this mountain 1660 m

geomorphometry and landform mapping what is a landform abstract starting from a concept of the land surface its definition and subdivision from digital elevation models dems is considered high resolution dems from active remote sensing form a new basis for geomorphological work which is moving on from consideration of whether data are accurate enough to how the surface of interest can be defined from an overabundance of data discussion of the operational definition and delimitation of specific landforms of varying degrees of difficulty from craters to mountains is followed by the applicability of fuzzy boundaries scaling usually allometric is shown to be compatible with the scale specificity of many landforms this is exemplified by glacial cirques and drumlins classification of a whole land surface is more difficult than extraction of specific landforms from it well dissected fluvial landscapes pose great challenges for areal analyses these are tackled by the delimitation of homogeneous elementary forms and or land elements in which slope position is considered the boundaries are mainly breaks in gradient or aspect but may also be in some type of curvature breaks in altitude are rare elementary forms or land elements are grouped together into functional regions landforms such as hill sheds it may often be useful to recognise fuzziness of membership or core and periphery of a surface object plains and etched or scoured surfaces defy most of these approaches and general geomorphometry remains the most widely applicable technique it has been applied mainly within arbitrary areas and to some extent to drainage basins but more experimentation with mountain ranges and other landforms or landform regions is needed geomorphological mapping is becoming more specialised and its legends are being simplified its incorporation into geographical information systems gis has required greater precision with definitions and the separation of thematic layers so that it is converging with specific geomorphometry and becoming more flexible and more applicable with a broader range of visualisation techniques

an integral image approach to performing multi scale topographic position analysis abstract digital elevation model dem derived measures of terrain ruggedness and relative topographic position are useful parameters for automated landform classification and are widely applied in soils vegetation and habitat mapping these elevation residual attributes are inherently scale dependent because they are defined in the context of a local neighborhood several previous studies have focused on assessing the multi scale properties of elevation residuals based on varying roving window sizes dem grid resolution resampling and hierarchical object based methods the computationally intensive nature of large window dem filtering has previously prevented the application of the varying roving window size approach from being applied to study the scaling properties of the terrain ruggedness and topographic position at broader regional scales this paper explores the use of an integral image based approach to measuring the common relative topographic position metric deviation from mean elevation dev the approach was applied to a large dem of an extensive and heterogeneous region in eastern north america compared with traditional image filtering techniques the integral image approach was extremely efficient for calculating dev enabling a fine resolution multi scale analysis of elevation residuals a method is described to allow for the measurement of dev at optimal scales for each grid cell within wide spatial scale ranges a novel technique is also developed for visualizing the scaling characteristics of topographic position using color composite imagery

composition effects on pore structure of transitional shale a case study of the upper carboniferous taiyuan formation in the eastern uplift of the liaohe depression china abstract transitional shale is very different from marine shale with respect to mineral composition and pore structure insights into the effects of rock composition on pore structure can aid understanding of the storage and migration mechanisms of shale gas in a reservoir to investigate the compositional effects on pore structure a combination of geochemical and petrophysical experiments were conducted on four bulk shale samples and their corresponding extracted organic matter om and clay mineral samples the experimental results show that the removal of om using h2o2 during clay mineral extraction oxidizes and removes pyrite and siderite from the samples while other inorganic phases remain unaffected om hosted more abundant micropores compared with clay minerals while mesopores and fine macropores are dominant in clay minerals effects of the om and clay minerals on pore volume and surface area are quantitatively evaluated on the basis of weight normalized pore size distribution psd curves of extracted om and clay mineral samples in terms of the co2 adsorption contribution from om and clay minerals to micropore volume miv are 19 43 32 92 and 18 75 39 05 respectively and to micropore surface area mis are 19 30 32 28 and 16 42 35 72 other minerals other than organic matter and clay minerals account for 34 29 48 93 of the miv and 39 75 52 98 of the mis n2 adsorption results reveal that the pore volume and surface area are mainly attributable to the clay minerals providing 54 37 80 75 of the bjh pore volume bjhv average 65 83 and 70 68 87 04 of the bet surface area bets average 78 71 the primary medium for pore development in marine shale is om whereas pores in the transitional shale are mostly found in the clay and other inorganic minerals therefore the hydraulic fracturing design and drilling related operations involved in the exploitation of transitional shale gas should be appropriately adjusted and improved in order to accommodate intrinsic characteristics of the transitional shale gas reservoir

evidence for weathering on early mars from a comparison with terrestrial weathering profiles abstract phyllosilicates on mars are widespread in the ancient crust suggesting the presence of liquid water at the martian surface and therefore warmer conditions during its early history however the role of the ancient climate in the alteration process which produced these phyllosilicates remains under debate because similar mineral assemblages can be produced by hydrothermal alteration at depth this paper focuses on the origin of coincident outcrops of fe mg bearing phyllosilicates and al bearing phyllosilicates which are observed in several regions of mars we performed a detailed mineralogical comparison between a section in nili fossae mars and a weathering profile located at murrin murrin western australia the murrin murrin profile is developed in archaean serpentinized peridotite massifs over a 40 m thick sequence it has three alteration zones the serpentine mineral saprolite is found at the bottom immediately overlain by fe mg bearing smectites and then al bearing phyllosilicates kaolinite mixed with iron hydroxides this example illustrates how al dominated minerals can derive from the alteration of initially al poor ultramafic rocks by the intense leaching of mg2 this mineralogical sequence is very similar to that detected locally in nili fossae by orbital spectroscopy by analogy we propose that the mineral assemblage detected on mars is the result of long term weathering and thus could be the best evidence of past weathering as a direct result of a climate significantly warmer than at present

reply to comment by p passalacqua and e foufoula georgiou on objective extraction of channel heads from high resolution topographic data

quantifying submerged fluvial topography using hyperspatial resolution uas imagery and structure from motion photogrammetry quantifying the topography of rivers and their associated bedforms has been a fundamental concern of fluvial geomorphology for decades such data acquired at high temporal and spatial resolutions are increasingly in demand for process oriented investigations of flow hydraulics sediment dynamics and in stream habitat in these riverine environments the most challenging region for topographic measurement is the wetted submerged channel generally dry bed topography and submerged bathymetry are measured using different methods and technology this adds to the costs logistical challenges and data processing requirements of comprehensive river surveys however some technologies are capable of measuring the submerged topography through water photogrammetry and bathymetric lidar are capable of reasonably accurate measurements of channel beds in clear water whilst the cost of bathymetric lidar remains high and its resolution relatively coarse the recent developments in photogrammetry using structure from motion sfm algorithms promise a fundamental shift in the accessibility of topographic data for a wide range of settings here we present results demonstrating the potential of so called sfm photogrammetry for quantifying both exposed and submerged fluvial topography at the mesohabitat scale we show that imagery acquired from a rotary winged unmanned aerial system uas can be processed in order to produce digital elevation models dems with hyperspatial resolutions c 0 02 m for two different river systems over channel lengths of 50 100 m errors in submerged areas range from 0 016 m to 0 089 m which can be reduced to between 0 008 m and 0 053 m with the application of a simple refraction correction this work therefore demonstrates the potential of uas platforms and sfm photogrammetry as a single technique for surveying fluvial topography at the mesoscale defined as lengths of channel from c 10 m to a few hundred metres this article is protected by copyright all rights reserved

fusion of multi resolution surface terrestrial laser scanning and subsurface geodata ert srt for karst landform investigation and geomorphometric quantification a multi method research design based on terrestrial laser scanning gis geophysical prospecting electrical resistivity tomography refraction seismics and sedimentology is applied for the first time to investigate enclosed karst depressions in an integrated way fusing multi resolution surface and subsurface geodata provides profound insights into the formation geometry and geomorphologic processes of dolines the studied landforms which are located in the dikti mountains of east crete are shown to be filled by loose sediments of thicknesses of up to 30 m that mainly consist of fine grained material overlying solid bedrock at depths below 35 to 45 m by combining subsurface observations with geomorphometric calculations local doline genesis can be traced back to initial collapse of fractured bedrock followed by subsequent infilling with colluvials in order to define crucial methodological requirements and guidelines for data fusion both the impact of different elevation models and the influence of data resolution are assessed surface volumes of depressions derived by the digital surface model are 7 21 higher than the results obtained from the terrain model due to vegetation similarly estimates of infill volume calculated on the basis of geophysical outcomes and elevation data differ by up to 13 calculations of the landforms current volumes i e total surface and subsurface volume however are fairly insensitive to raster resolution hence the distinct geomorphologic properties of landforms e g shape terrain roughness slope inclination substantially determine the geomorphometric analysis of both surface and subsurface data as shown by the findings data fusion to integrate digital terrain geophysical and sedimentological datasets of varied resolutions benefits geomorphologic studies and helps provide a comprehensive image of landforms copyright 2013 john wiley sons ltd

the italian cmt dataset from 1977 to the present abstract the ingv harvard european mediterranean regional centroid moment tensor rcmt catalog collects solutions routinely computed since 1997 for earthquakes with moderate magnitude 4 5 m 5 5 in the mediterranean region the database represents an extension to smaller magnitudes of the harvard global cmt catalog based on analysis of seismograms recorded at regional distance and modeling of intermediate period surface waves the catalog includes about 600 events 200 of which in the italian region this study extends the catalog back in time for the italian region as long as made possible by available digital data i e since 1977 with the same analysis and inversion method used for current seismicity as a result we present here 65 new moment tensors for years between 1977 and 1997 these solutions represent 45 of the total number of events analyzed the existing seismograms being often too scarce to allow a stable solution the new dataset includes events in many seismic zones where moderate seismicity had previously been scarcely documented e g the po plain the central to southern apennines and the adriatic sea the complete dataset including previously determined rcmts and cmts represents the seismic deformation in the italian area during the last 25 years

digital soil pattern recognition in the lower namoi valley using numerical clustering of gamma ray spectrometry data abstract digital soil mapping involves the use of ancillary data e g proximal and remotely sensed as surrogates for soil information to produce maps of soil type or classes two of the most popularly used sources of ancillary data are the proximally sensing electromagnetic em induction instruments and remotely sensed digital elevation model data dem however these data have limitations at the catchment level and are of limited use on predominantly flat alluvial landscapes respectively another option is the use of remotely sensed gamma ray ray spectrometry data which has successfully been used to map the regolith in this paper the use of ray spectrometry data i e potassium k uranium u thorium th and total count tc coupled with a numerical clustering algorithm i e fuzzy k means fkm algorithm is explored in order to identify geological and geomorphological units at the district and soil mapping units at a broader catchment level we do this by using the euclidean distance and the measures of fuzziness performance index fpi and normalized classification entropy nce to identify k 11 classes and a fuzziness exponent 2 0 for interpretation the k 11 classes produce contiguous classes which are consistent with geological and geomorphological interpretations of an eroded landscape alluvial lands and dust mantled alluvial lands at the district level at the sub catchment level the k 11 classes also match broad soil mapping units and also elucidate subtle differences of the alluvial lands which characterise the agriculturally significant parts of the lower namoi valley fuzzy canonical analysis shows that k and tc contribute most to the discrimination of the classes associated with the trachyte rich parts of the eroded landscape the alluvial lands and most of the dust mantled alluvial lands whilst u and th discriminate the basaltic outliers and other geomorphological units of the eroded lands we conclude that the approach allows soil management and landscape units to be identified with the information used as a first approximation to determine where soil sample locations need to be collected to validate the map units identified in order to better incorporate and characterise subsoil properties the inclusion of em signal data e g em38 or dualem 1 may also be appropriate

trends in publications in fluvial geomorphology over two decades a truly new era in the discipline owing to recent technological revolution abstract trends in the field of fluvial geomorphology have been reviewed by a number of authors who have emphasized the dramatic change occuring in the field in the last two decades of the twentieth century largely as a result of technological advances nevertheless no prior authors have systematically compiled data on publications in fluvial geomorphology over a long period and statistically analyzed the resulting data set in this contribution we present a quantitative analysis of fluvial geomorphology papers published in the twenty two year period 1987 2009 in five journals of the discipline with a more specific focus on geomorphology and earth surface processes and landforms espl identifying authorships geographic origin of authors and spatial and temporal scales covered we also documented the tools employed demonstrating the transformation of the field with the emergence of new tools over this period and conducted a cluster to highlight links between tools and a set of factors country of author s origin journals time and spatial and temporal scales of the 1717 papers published in the five journals during this period the results showed an increased diversity in the nationality of the first author mainly when dealing with present time scale and channel feature our data show a significant change in methods used in the field as a result of the increase in data availability and new sources of information from remote sensing ground airborne and satellite clearly a new era in knowledge production is observed since 2000 showing the emergence of a second period of active quantification and an internationalization of the fields

application of wavelet analysis to the study of spatial pattern of morphotectonic lineaments in digital terrain models a case study tectonic faults are often associated with characteristic geomorphological features such as linear valleys ridgelines and slope breaks that can be identified as lineaments in remotely sensed images or digital terrain models lineaments of tectonic origin are often characterised by periodicity and characteristic spatial pattern unlike traditional methods of autocorrelation variogram lineament density and fourier analysis wavelet analysis is capable of capturing and describing both periodicity and spatial pattern of lineaments in this paper a case study is shown for the application of wavelet analysis to morphotectonic lineament investigation results of wavelet analysis are compared to traditional methods although this study involves dem derived morphological lineaments the presented wavelet analysis can be also used for lineaments derived from remotely sensed images these results hold for this case study and provide a good assessment of the relative abilities of wavelet analysis but it remains to be seen how effective it is for other data sources areas and geological terrain

initial observations from the lunar orbiter laser altimeter lola as of june 19 2010 the lunar orbiter laser altimeter an instrument on the lunar reconnaissance orbiter has collected over 2 0 10 9 measurements of elevation that collectively represent the highest resolution global model of lunar topography yet produced these altimetric observations have been used to improve the lunar geodetic grid to 10 m radial and 100 m spatial accuracy with respect to the moon s center of mass lola has also provided the highest resolution global maps yet produced of slopes roughness and the 1064 nm reflectance of the lunar surface regional topography of the lunar polar regions allows precise characterization of present and past illumination conditions lola s initial global data sets as well as the first high resolution digital elevation models dems of polar topography are described herein

assessing the performance of structure from motion photogrammetry and terrestrial lidar for reconstructing soil surface microtopography of naturally vegetated plots soil microtopography is a property of critical importance in many earth surface processes but is often difficult to quantify advances in computer vision technologies have made image based three dimensional 3d reconstruction or structure from motion sfm available to many scientists as a low cost alternative to laser based systems such as terrestrial laser scanning tls while the performance of sfm at acquiring soil surface microtopography has been extensively compared to that of tls on bare surfaces little is known about the impact of vegetation on reconstruction performance this article evaluates the performance of sfm and tls technologies at reconstructing soil microtopography on 6 m 2 m erosion plots with vegetation cover ranging from 0 to 77 results show that soil surface occlusion by vegetation was more pronounced with tls compared to sfm a consequence of the single viewpoint laser scanning strategy adopted in this study on the bare soil surface elevation values estimated with sfm were within 5 mm of those from tls although long distance deformations were observed with the former technology as vegetation cover increased agreement between sfm and tls slightly degraded but was significantly affected beyond 53 of ground cover detailed semivariogram analysis on meter square scale surface patches showed that tls and sfm surfaces were very similar even on highly vegetated plots but with fine scale details and the dynamic elevation range smoothed out with sfm errors in the tls data were mainly caused by the distance measurement function of the instrument especially at the fringe of occlusion regions where the laser beam intersected foreground and background features simultaneously from this study we conclude that a realistic approach to digitizing soil surface microtopography in field conditions can be implemented by combining strengths of the image based method simplicity and effectiveness at reconstructing soil surface under sparse vegetation with the high accuracy of tls like technologies copyright 2015 john wiley sons ltd

from experimental plots to experimental landscapes topography erosion and deposition in sub humid badlands from structure from motion photogrammetry in the last decade advances in surveying technology have opened up the possibility of representing topography and monitoring surface changes over experimental plots 10 m2 in high resolution 103 points m 1 yet the representativeness of these small plots is limited with structure from motion sfm and multi view stereo mvs techniques now becoming part of the geomorphologist s toolkit there is potential to expand further the scale at which we characterise topography and monitor geomorphic change morphometrically moving beyond previous plot scale work using terrestrial laser scanning tls surveys this paper validates robustly a number of sfm mvs surveys against total station and extensive tls data at three nested scales plots 30 m2 within a small catchment 4710 m2 within an eroding marl badland landscape 1 km2 sfm surveys from a number of platforms are evaluated based on i topography ii sub grid roughness and iii change detection capabilities at an annual scale oblique ground based images can provide a high quality surface equivalent to tls at the plot scale but become unreliable over larger areas of complex terrain degradation of surface quality with range is observed clearly for sfm models derived from aerial imagery recently modelled doming effects from the use of vertical imagery are proven empirically as a piloted gyrocopter survey at 50m altitude with convergent off nadir imagery provided higher quality data than an unmanned aerial vehicle uav flying at the same height and collecting vertical imagery for soil erosion monitoring sfm can provide data comparable with tls only from small survey ranges 5 m and is best limited to survey ranges 10 20 m synthesis of these results with existing validation studies shows a clear degradation of root mean squared error rmse with survey range with a median ratio between rmse and survey range of 1 639 and highlights the effect of the validation method e g point cloud or raster based on the estimated quality

current transition from glacial to periglacial processes in the dolomites south eastern alps abstract a close relationship between glacial and periglacial landforms is frequently observed in alpine environments where a transition from glacial to periglacial processes often took place after the end of the little ice age lia understanding the origin of these landforms is challenging and assessing the current spatial domain of glacial and periglacial processes may be a difficult task in high relief areas where thick and widespread debris cover often characterize rapidly decaying glaciers here we present a comprehensive study of a composite landform located in the dolomites south eastern alps combining geomorphological geophysical and topographic surveys with ground surface temperature measurements results indicate that a debris covered glacier persists in the upper part rather large compared to the lia extent but currently inactive and rapidly losing mass an active rock glacier exists in the lower part surrounded by discontinuous permafrost a frozen body about 10 m thick was detected in the rock glacier and geomorphological evidence suggests that this ice mass is completely detached from the debris covered glacier our findings suggest that the lower part of the composite landform is probably a remnant of the ancient glacier tongue and is currently evolving under periglacial conditions periglacial processes are therefore replacing glacial processes which dominated in this site during the lia

identifying multiscale zonation and assessing the relative importance of polygon geomorphology on carbon fluxes in an arctic tundra ecosystem we develop a multiscale zonation approach to characterize the spatial variability of arctic polygonal ground geomorphology and to assess the relative controls of these elements on land surface and subsurface properties and carbon fluxes working within an ice wedge polygonal region near barrow alaska we consider two scales of zonation polygon features troughs centers and rims of polygons that are nested within different polygon types high flat and low centered in this study we first delineated polygons using a digital elevation map and clustered the polygons into four types along two transects using geophysical and kite based landscape imaging data sets we extrapolated those data defined polygon types to all the polygons over the study site using the polygon statistics extracted from the digital elevation map based on the point measurements we characterized the distribution of vegetation hydrological thermal and geochemical properties as well as carbon fluxes all as a function of polygon types and polygon features results show that nested polygon geomorphic zonation polygon types and polygon features can be used to represent distinct distributions of carbon fluxes and associated properties as well as covariability among those properties importantly the results indicate that polygon types have more power to explain the variations in those properties than polygon features the approach is expected to be useful for improved system understanding site characterization and parameterization of numerical models aimed at predicting ecosystem feedbacks to the climate

combining geomorphometry feature extraction techniques and earth surface processes research the way forward abstract in recent years the wealth of technological development revolutionised our ability to collect data in geosciences due to the unprecedented level of detail of these datasets geomorphologists are facing new challenges giving more in depth answers to a broad er range of fundamental questions across the full spectrum of the earth s and planetary processes this contribution builds on the existing literature of geomorphometry the science of quantitative land surface analysis and feature extraction translate land surface parameters into extents of geomorphological elements it provides evidence of critical themes as well as emerging fields of future research in the digital realm supporting the likely effectiveness of geomorphometry and feature extractions as they are advancing the theoretical empirical and applied dimension of geomorphology the review further discusses the role of geomorphometric legacies and scientific reproducibility and how they can be implemented in the hope that this will facilitate action towards improving the transparency and efficiency of scientific research and accelerate discoveries in geomorphology in the current landscape substantial changes in landforms ecosystems land use hydrological routing and direct anthropogenic modifications impact systems across the full spectrum of geomorphological processes although uncertainties in the precise nature and likelihood of changes exist geomorphometry and feature extraction can aid exploring process regimes and landscape responses taken together they can revolutionise geomorphology by opening the doors to improved investigations crossing space and time scales blurring the boundaries between traditional approaches and computer modelling and facilitating cross disciplinary research ultimately the exploitation of the available wealth of digital information can help to translate our understanding of geomorphic processes which is often based on observations of past or current conditions into the rapidly changing future

the anthropocene is there a geomorphological case the anthropocene as used to describe the interval of recent earth history during which humans have had an overwhelming effect on the earth system is now being formally considered as a possible new geological epoch such a new geological time interval possibly equivalent to the pleistocene epoch requires both theoretical justification as well as empirical evidence preserved within the geological record since the geological record is driven by geomorphological processes that produce terrestrial and near shore stratigraphy geomorphology has to be an integral part of this consideration for this reason the british society for geomorphology bsg has inaugurated a fixed term working group to consider this issue and advise the society on how geomorphologists can engage with debates over the anthropocene this esex commentary sets out the initial case for the formalisation of the anthropocene and a priori considerations in the hope that it will stimulate debate amongst and involvement by the geomorphological community in what is a crucial issue for the discipline the working group is now considering the practical aspects of such a formalization including the relative magnitude problem the boundary problem and the spatial diachrony of anthropogenic geomorphology copyright 2013 john wiley sons ltd

quantitative analysis of land surface topography land surface topography significantly affects the processes of runoff and erosion a system which determines slope aspect and curvature in both the down slope and across slope directions is developed for an altitude matrix also the upslope drainage area and maximum drainage distance are determined for every point within the altitude matrix a fortran 66 program performs the analysis