ISSN 2047-0371
Geomorphological mapping
Jan-Christoph Otto1 and Mike J. Smith2 1Department of Geography and Geology, University of Salzburg, Austria (jan- [email protected]) 2 Department of Geography, Geology and Environment, Kingston University London ([email protected])
ABSTRACT: Geomorphological mapping is regarded as a fundamental technique of the discipline producing valuable base data for geomorphological and environmental research and practice. Geomorphological maps can be considered graphical inventories of a landscape depicting landforms and surface as well as subsurface materials. Geomorphological mapping is a preliminary tool for land management and geomorphological risk management, also providing baseline data for other sectors of environmental research such as landscape ecology, forestry or soil science. The widespread distribution and extended graphical capabilities of GIS-software as well as the availability of high-resolution remote sensing data such as aerial and satellite imagery or digital elevation data has led to a rejuvenation of the method. This chapter outlines the history, creation and dissemination of geomorphological maps; it provides a brief overview of field and digital mapping techniques, as well as introductory information on cartographic principles applied to geomorphological mapping. Finally, there are a range of key references that can aid the reader by providing more in-depth information on selected topics. KEYWORDS: map, GIS, cartography, DEM
Introduction Doornkamp, 1990, Dramis et al., 2011, Paron and Claessens, 2011). Geomorphological maps can be considered graphical inventories of a landscape depicting Geomorphological maps can be categorised landforms and surface as well as subsurface as basic or analytical and derived or materials. Sketches and maps of landscapes specialised. Whilst basic maps represent the and landforms (e.g. Dykes, 2008) have been observed features of a landscape, derived fundamental methods to analyse and maps are focused on a specific theme or visualise Earth surface features ever since application. One example of derived maps early geomorphological research. The are geomorphological hazard maps that widespread distribution and extended depict risk-causing phenomena and their graphical capabilities of geographic magnitude and frequency (Dramis, et al., information systems (GIS) as well as the 2011). Basic geomorphological maps may availability of high-resolution remote sensing either focus on selected landscape features, data such as aerial and satellite imagery and for example only depicting the morphology of digital elevation models (DEMs) has led to active processes, or deliver a full view on the the recent rejuvenation of the method (Lee, landscape composition and its evolution 2001, Paron and Claessens, 2011, Smith et (Knight et al., 2011, Verstappen, 2011). al., 2011). Geomorphological maps can act as a preliminary tool for land management In contrast to other types of geoscientific and geomorphological and geological risk maps, very little international standardisation management, as well as providing baseline exists for geomorphological mapping data for other applied sectors of legends. In the second half of the 20th century environmental research such as landscape different legend systems developed in ecology, forestry or soil science (Cooke and
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) Geomorphological Mapping 2
various European countries (Barsch and Table 1. Workflow for undertaking Liedtke, 1980, Brunsden et al., 1975, geomorphological field mapping (modified Embleton and Verstappen, 1988, Evans, from: Knight et al. 2011) 1990, Klimaszewski, 1982, Pellegrini, 1993, Schoeneich et al., 1998, Tricart, 1965). The Activity choice of mapping symbols (or legend Pre-Mapping: system) is determined by the purpose of the - Identify region of interest map, the message to communicate and the targeted group of users. It is therefore - Identify purpose or goal of mapping important to analyse and plan these - Obtain remote sensing data conditions before starting a mapping - Obtain geological and soils mapping campaign. The application of complex information symbols using GIS or graphic software may - Design and create a GIS database influence the selection of the legend system. This chapter outlines the techniques for the - Compose a field mapping protocol creation and dissemination of - Map major morphological forms using geomorphological maps; it provides a brief remote sensing data overview of field and digital mapping - Create draft map at a suitable scale for techniques, as well as introductory field mapping information on cartographic principles applied - Prepare legend systems and symbols to geomorphological mapping. Finally, there are a range of key references that can aid the - Obtain permission for access to the reader by providing more in-depth information mapping region on selected topics. - Conduct risk assessment for the planned activities Field Mapping - Obtain weather forecast During the field campaign: Despite the growing offer of high resolution digital information on the Earth's land surface - Conduct field mapping following the the visual impression gained from direct protocol, including walking the area observation in the field provides - Use hand-held GPS to mark tracks or unprecedented detail and access. Field waypoints observation, and subsequent mapping, - Write notes and take photos, positioned allows the most direct way to appreciate a using GPS landscape’s character and enables a basis - Adhere to health and safety issues for terrain assessment and geomorphological and/or update the risk assessment analysis. Though field mapping by its nature is subjective and affected by the skills Post-Mapping: (experience) of the mapper, it allows the - Download and integrate GPS data with mapper to become familiar with the the existing GIS database landscape (Cooke and Doornkamp, 1990). - Compare field and remote sensing This is a crucial aspect as it enables mapping in order to validate remotely exploratory investigation through direct sensed observations observation of surface morphologies and - Write up notes and integrate notes with subsurface exposures; this allows the photos development of a "mental model" of the landscape which can be incorporated in to - Produce final geomorphological map in later interpretation and analysis. the GIS software - Draw final map using analogue or digital The production of good and purposeful maps cartographic symbols either using the in the field requires a clear definition of the GIS software, or graphic design aims and objectives. The mapping procedure software includes (i) pre-field preparatory steps, (ii) the - Write and present explanatory notes actual field work and (iii) post mapping accompanying the map activities that result in the creation of a - Publish the map publishable final map (Table 1).
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) 3 Jan-Christoph Otto & Mike Smith
Typical preparation includes the gathering of When using digital devices such as mobile additional information on the area (location, field computers, mapping is generally accessibility, history, and previous work), the performed using field mapping software. This choice of mapping scale and symbols, as well allows for the digitisation of vector data as planning the mapping campaign (Knight, directly onto the screen. The base data for et al., 2011). The analysis of aerial imagery mapping (topographic map, aerial photo, or DEMs helps to familiarise the observer DEM) are stored on the field device. For with the field area and should always be exact positioning the field computer should performed before mapping. This results in a be connected to a GPS. The application of a draft map that includes major landforms digital mapping device requires the mapped from the remote sensing data. The preparation of the GIS data base structure draft map is taken into the field for prior to the field campaign (Figure 1). verification, addition of detail and delineation of exact boundaries. The creation of a field mapping protocol that details the steps of the mapping campaign is important as it allows the organised collection of additional information on landforms and the creation of a database for the data mapped in the field (Knight, et al., 2011).
The mapping scale used for data recording is usually larger than the scale of the final map in order to collect as many details in the field as possible. Typical detailed field maps are created at a mapping scale of 1:3000 to 1:25,000, whilst detailed geomorphological maps have scales between 1:5000 and 1:50,000. Consequently, map production requires generalisation of the field data. It is worth noting that medium and small scale geomorphological maps exist, ranging from 1:100,000 to > 1:1,000,000 (Dramis, et al., 2011).
Key equipment Paper based (analogue) field mapping is usually performed using tracing paper, a topographic map of the area of interest, a clipboard and a pencil. The topographic map is used for orientation and location and should be enlarged to the mapping scale. Aerial photos and/or relief shaded (see below) images at the same scale are also useful. Other tools include a global positioning system (GPS) receiver for the collection of waypoints or the exact positioning of boundaries and objects. Additionally, binoculars are useful particularly in mountain areas to investigate inaccessible Figure 1. A typical GIS data base structure terrain. In order to have all the required for a geomorphological mapping project (after symbols at hand, the legend system of the Gustavsson et al., 2008). symbols should be printed out and taken into the field.
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) Geomorphological Mapping 4
Mapping procedure Manual Mapping A typical field mapping campaign starts with a Manual approaches rely on the experience 'walk through' to generate an overview of the and skill of an individual mapper using visual area. This enables an estimate of the time for heuristics to identify landforms of interest mapping and planning of the route through (Colwell, 1983); accuracy is generally high, the study area in accordance with the field the method is simple and rapid to deploy, protocol. The mapping itself starts with the however this is at the expense of an objective marking of breaks of slopes or a verification and repeatable approach. The representation of the draft map contents. One method for of a landform on an image is dependent avoiding overload of the field map sheets is upon: (i) the landform itself, (ii) the data to use separate sheets of tracing paper for source and (iii) the method used to process it each layer of information; for example (visualisation method). morphology, process, and surface material. Mapping of processes usually requires For satellite imagery a range of standard interpretation from surface form and material image enhancement techniques can be composition since few active processes will applied; these include false colour be observed 'live' in the field. Mapping of composites, band ratios, convolution filtering surface and subsurface material is usually and contrast stretches. However there are performed by visual interpretation or rapid three main controls on landform field sampling. The goal of material mapping representation (Smith and Wise, 2007): (i) lies in the identification of material patterns relative size: the size of the landform relative rather than detailed sediment analysis to the spatial resolution, (ii) azimuth biasing: (Dackombe and Gardiner, 1983). the orientation of the landform with respect to solar azimuth and (iii) landform signal Mapping speed depends upon the strength: the tonal/textural differentiation of experience of the observer and the ground the landform. For any specific image used for conditions. Even though mapping in mapping there is a minimum resolvable mountainous regions may be more time landform size and a range of landform consuming due to the rough terrain, orientations (which is more pronounced the mountains/hills often provide a better view of greater the linearity) at which they can be the landscape compared to flat terrain that represented. The definition of these needs to be walked through completely in landforms is then determined by their relative order to see all features. An experienced reflectance in comparison to surrounding mapper is able to map up to 2-3 km²/day, features. Smith and Wise (2007) recommend depending on local conditions and the acquisition of imagery with solar elevation complexity of terrain. angles <20º in order to enhance the topographic "signal" through shadowing.
For DEMs only the issue of relative size holds Digital Mapping true and as a result they should offer more Where field mapping is not practical, it is refined visualisations for mapping (Hillier and common practice to utilise digital data Smith, 2008, Smith and Clark, 2005, Smith et sources (Smith and Clark, 2005, Smith and al., 2013). DEM processing is a subject area Pain, 2009, Oguchi et al., 2011, Smith, 2011) of itself known as geomorphometry (Hengl to compile mapping within the framework of a and Reuter, 2008), with land surface GIS. Primary data sources include aerial parameters (LSPs) the processed photography, satellite imagery and DEMs - "derivatives" of the raw elevation data; these care should be taken in the selection of data are used to present visualisations for manual so that it is at an appropriate scale and mapping. provides sufficient coverage of the study area. The user then has two options for The most common method is relief shading performing mapping: (1) manual and (2) which mimics a satellite image by placing an automated or semi-automated. artificial sun in the sky and calculating the shadowing (Figure 2a). It is intuitive to view and highlights subtle topographic features,
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) 5 Jan-Christoph Otto & Mike Smith
however it reintroduces the above controls on a localised increase in contrast. RRS (Hillier representation, particularly azimuth biasing. It and Smith, 2008) takes a different approach is therefore desirable to utilise methods that and begins with the conceptual are free from azimuth biasing, however these understanding that landscapes are comprised may not improve identification rates of of different elevation elements that are landforms (Smith and Clark, 2005); in "stacked" on top of one another - these often addition, if interpreters are not familiar with occur at different width-scales and if the the output from these techniques, then they regional-scale relief is removed, then the may find landform identification more difficult. small-scale "remainder" (or residual) can be extracted. These residuals ideally only Gradient is perhaps the most common contain features of interest, however as this method (Figure 2b) and measures the is a scale-based technique it will contain all steepness of slope (rate of change of features at that scale and this can include elevation); as landforms often have steep anthropogenic features. sides they can be readily identified. The rate of change of gradient is curvature and is Semi-Automated Mapping comprised of three components (Schmidt et al., 2003): profile, planform and tangential. Given the benefits of objective and repeatable methods, automated and semi- Profile curvature is particularly pertinent as it automated techniques are highly desirable. measures downslope curvature, helping They utilise algorithms to quantitatively identify breaks-of-slope. Two other common process input data in order to identify methods include local contrast stretch (LCS) landforms, however the complexity of the and residual relief separation (RRS). LCS process often results in low or moderate (Smith and Clark, 2005) uses the concept of levels of accuracy when compared to manual relative elevation and that a landform is methods - as a result this remains an active spatially distinct from neighbouring features - topic of research that is evolving rapidly a standard linear contrast stretch is applied to (Seijmonsbergen et al., 2011). The area a region of a specified size, thereby providing borrows heavily from the classification of
Figure 2 Illustrating the effect of relief shading (a) and gradient (b; darker tones are steep slopes) on the detectability of drumlins from high resolution DEMs of the same area
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) Geomorphological Mapping 6
satellite imagery (Mather, 2004) where landscape with all its elements on a two- feature extraction techniques are used to dimensional sheet of paper. To deliver this identify surface features using reflectance at complex information, geomorphological maps different wavelengths. For mapping, different make full use of a variety of elements of wavelength inputs are replaced with different cartographic design. Different kinds of LSPs and then processed using either symbols and colours need to be arranged supervised or unsupervised techniques and composed carefully in order to generate (Lillesand et al., 2008). Supervised a readable map that clearly expresses the techniques require interaction with a mapper content and message of the project. and include methods such as rule-based object classification, cluster analysis (e.g. Before starting the process of map design it maximum likelihood) and regression is necessary to review the following questions analyses. Unsupervised techniques involve (Otto et al., 2011): unsupervised object based classification, What is the purpose, message, and clustering (e.g. k-means), and machine central theme of the map? learning. Perhaps the most promising approach is rule-based object classification Who has commissioned the map? (Blaschke, 2010), more commonly termed object-based image analysis (OBIA). Unlike Who will be using the map? more "traditional" remote sensing based How will the reader use the map classification techniques that operate on a (office, field)? pixel-by-pixel approach, OBIA operates on the fundamental principle that landforms are Applications of geomorphological maps range conglomerations of pixels. The two-stage from simple descriptions of a field site, for process begins by using input LSPs to example accompanying a journal publication segment the image in to clusters of pixels or construction site report, to specialised land using a multi-scale algorithm; once complete system analyses, for example for land a set of classification rules is then applied to management or natural hazard assessment. the objects The segmentation is controlled by It is equally important to consider the parameters restricting the size and shape of production process and dissemination of the clusters, with the size particularly important final product. Is it a paper map? Is the map for landforms - recent developments have produced in colour or black and white? Is the seen automated techniques for optimising the map accompanying a journal publication? scale parameter for landform extraction Will it be published online? These issues (Anders et al., 2011, Dragut et al., 2010). strongly influence how to compile and arrange the data, which symbols are used, It is worth noting that testing mapping how the various map items are composed techniques is a difficult task as it requires a and whether colour can be used or not (Otto, pre-existent knowledge of landforms to et al., 2011). determine if an identification of individual features is successful. A higher spatial Communication with maps differs significantly resolution dataset or manual mapping under from other types of human communication. "controlled" conditions are often used. Hillier Maps are visual media and evoke visual and Smith (2012) take a different approach stimuli that cause different reactions in and place synthetic landforms in a real people than books or conversations. Graphic landscape allowing a priori knowledge of the communication, like maps, delivers all landforms present. This can allow information at once. That means information unequivocal testing of the landform mapping is not perceived sequentially, but method. instantaneously with respect to the location and relative position on the map sheet or screen. Thus, the appearance and Digital Output composition of graphical elements need to be considered thoughtfully. On a map, all Geomorphological maps are a specific kind of information is spatially related and should be thematic map that use complex and considered holistically. The composition of illustrative symbolisation. The challenge of map items determines if and how the reader mapping is to portray a three-dimensional
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) 7 Jan-Christoph Otto & Mike Smith
understands the message, with perception terrain, for example mountain areas, the and understanding occurring subconsciously. greater the diversity of symbols and colours To allow map-users to understand the required (Verstappen, 2011). meaning of the map, a visual link to the symbols and their attributes that correspond In general geomorphological maps and their to the intention of the cartographer needs to legend systems can be differentiated into be assigned (Robinson et al., 1995). maps showing a single aspect of geomorphology, most commonly morphology,
and analytical maps that encompass the full The basis for most geomorphological maps is information of a landscape including a topographic base map presenting contour processes, morphogenesis and even lines and the general layout of the lithology (Knight et al., 2011, Verstappen, hydrography and infrastructure. The basic 2011). An overview of different legend representations of objects on maps are the systems is provided by Otto et al. (2011), in symbol primitives: point, line, and area (also part highlighting how different countries have referred to as marker, line and polygon developed their own systems, either formally symbols) (Robinson et al., 1995). Whether a or informally, to suit their own cultural needs. linear feature in nature is represented by a line symbol on the map is primarily a question In Britain most geomorphological maps focus of scale. For example, a river could be on the representation of form producing depicted by a blue line. On larger maps (with morphological maps (Cooke and Doornkamp, increasing size of the map items) the river 1990, Evans, 1990) with significant breaks in would be depicted using an area symbol of slope the most dominant information. The the river shoreline. The map scale also purely morphometric information can be determines if a landform is depicted by a extended by morphogenetic and material point symbol, or if it is split into its information to complete the geomorphological morphological components. Rock glaciers for representation of landscapes. example could be represented by a single point symbol on small scale maps, or by the Most maps are generated using GIS or assemblage of line and area symbols that graphic design software, but only a few differentiate the step height of the rock glacier symbols sets exist that have been developed front, furrows and ridges and the for digital application. Many legend symbols accumulation of boulders and blocks on top are so complex that automated drawing by of the rock glacier, if the map scale increases GIS/graphic design software is not possible. (Otto et al., 2011). Among the few exemptions are the "Mapping
Symbols for High Mountains" (Otto, 2008, Line and pattern symbols (or shading) are Otto and Dikau, 2004) and the legend for commonly used for illustrating gradient and geomorphological mapping developed by the morphology. Some guidelines for the creation Institute de Géographie de l’Université de of geomorphological maps have been Lausanne (IGUL) (Maillard et al., 2011, established by the International Geographical Schoeneich et al., 1998) which can be used Union (IGU) Subcommission of with Esri ArcGIS. Figure 3 shows a Geomorphological Survey and Mapping geomorphological map of a high alpine valley (Gilewska, 1968). (Käfertal, Austria) produced in ArcGIS using
the symbol set of Otto (2008). Geomorphological legend systems A large number of symbols and legends have Online maps been developed since the onset of Digitally produced geomorphological maps geomorphological mapping in the early 20th hold the potential for online publication. The century (Passarge, 1914). The impressive possibilities range from simple publication of diversity of concepts and cartographic raster maps or single vector layers as conventions created in different scientific overlays for Google Earth to the generation of communities throughout Europe and the US a genuine webGIS application containing is related to the terrain configuration of the each single layer of information of the surveyed region and the scientific focus and geomorphological map. While the former is aim of the map. The more complex the
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) Geomorphological Mapping 8
Figure 3: Geomorphological map of the Kafertal, Hohe Tauern, Austrian Alps using the "Mapping Symbols for High Mountains" (Otto, 2008, Otto and Dikau, 2004). easily performed by export of maps or data layers into the standardised KML/KMZ Conclusions format, the latter requires a web server Geomorphological mapping is undergoing a application (webGIS software) for the renaissance - with geomorphology proving to dissemination of the map online. Otto, et al. be a cross-cutting discipline, integrating (2011) and Smith, et al. (2013) provide an academic and professional applications, the introduction to these methods for online positive impacts upon society are large. publication. Knowing where a landform is, why it is there, what it is made of and how it has changed is Recently, the standard PDF (Portable an incredibly powerful position from which to Document Format) has been extended into a manage society's interaction with surface GeoPDF for display and dissemination of (and near-surface) features. referenced map data. Geospatial functionality of a GeoPDF includes scalable map display, The re-emergence of geomorphological layer visibility control, access to attribute mapping as the pre-eminent paradigm for data, coordinate queries, and spatial such studies is a direct result of the measurements. Some geospatial data proliferation of spatial data (aerial and providers such as the United States satellite imagery, DEMs) and IT systems to Geological Survey (USGS; manage them (GIS). A clear framework for http://store.usgs.gov) and the Australian geomorphological spatial data management Hydrographic Service (AHS; has been established. Whilst the 1960s and http://www.hydro.gov.au/) currently publish 1970s saw initial academic development, interactive maps using the GeoPDF format. application was limited and as geomorphology as a discipline shifted to field- based studies interest declined. Indeed the mantle of geomorphological mapping shifted to engineering geology during the 1980s and
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) 9 Jan-Christoph Otto & Mike Smith
1990s as the benefits for direct application Dramis F, Guida D, Cestari A. 2011. Nature were recognised. The forefront of and Aims of Geomorphological Mapping. In geomorphology has seen the integration of Geomorphological Mapping: methods and process-level understanding with regional applications. Smith MJ, Paron P, Griffiths J scale modelling. GIS provides the underlying (eds.). Elsevier: London, 39-74 framework; maps and mapping are an Dykes AP. 2008. Geomorphological maps of integral part of this process and the skills, Irish peat landslides created using hand-held knowledge and understanding of the methods GPS. Journal of Maps 2008: 258-276 for data collection, processing and output are a key element. Geomorphological mapping is Embleton C, Verstappen HT. 1988. The the underpinning domain as geomorphology nature and objectives of applied moves centre-stage. geomorphological mapping. Zeitschrift für Geomorphologie, Supplementband 68: 1-8 References Evans IS. 1990. Cartographic techniques in geomorphology. In Geomorphological Anders NS, Seijmonsbergen AC, Bouten W. techniques. Goudie A (eds.). Unwin Hyman: 2011. Segmentation optimization and stratied London, 97-108 objectbased analysis for semi-automated geomorphological mapping. Remote Sensing Gilewska SK, M. 1968. Project of the Unified of Environment 115: 2976-2985 key to the geomorphological map of the World. Folia Geographica, Ser. Geographica- Barsch D, Liedtke H. 1980. Principles, Physica II. Polska Akademia Nauk, Kraków: scientific value and practical applicability of the geomorphological map of the Federal Gustavsson M, Seijmonsbergen AC, Kolstrup Republic of Germany at the scale of 1 : E. 2008. Structure and contents of a new 25,000 (GMK 25) and 1 : 100,000 (GMK geomorphological GIS database linked to a 100). Zeitschrift für Geomorphologie Suppl. geomorphological map - With an example 36: 296-313 from Liden, central Sweden. Geomorphology 95 (3-4): 335-349. Blaschke T. 2010. Object based image analysis for remote sensing. ISPRS Journal Hengl T, Reuter HI. 2008. Geomorphometry: of Photogrammetry and Remote Sensing 65 Concepts, Software, Applications. Elsevier: (1): 2-16 Hillier JK, Smith M. 2008. Residual relief Brunsden D, Doornkamp JC, Fookes PG, separation: digital elevation model Jones DKC, Kelly JMH. 1975. Large scale enhancement for geomorphological mapping. geomorphological mapping and highway Earth Surface Processes and Landforms 33 engineering design. Quarterly Journal of (14): 2266-2276. Engineering Geology 8: 227-253 Hillier JK, Smith MJ. 2012. Testing 3D Colwell RN. 1983. Manual of Remote landform quantification methods with Sensing. American Society of synthetic drumlins in a real digital elevation Photogrammetry: Washington model. Geomorphology 153–154: 61-73 Cooke RU, Doornkamp JC. 1990. Klimaszewski M. 1982. Detailed Geomorphology in environmental geomorphological maps. ITC Journal 3: 265- management, A New Introduction. Clarendon 271 Press: Oxford Knight J, Mitchell W, Rose J. 2011. Dackombe RV, Gardiner V. 1983. Geomorphological Field Mapping. In Geomorphological field manual. George Allen Geomorphological Mapping: methods and & Unwin: London applications. Smith MJ, Paron P, Griffiths J (eds.). Elsevier: London, 151-188 Dragut L, Tiede D, Levick S. 2010. ESP: a tool to estimate scale parameter for Lee EM. 2001. Geomorphological mapping. multiresolution image segmentation of Geological Society Special Publication (18): remotely sensed data. International Journal 53-56 of Geographical Information Science 24 (4): 859-871
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013) Geomorphological Mapping 10
Lillesand T, Kiefer RW, Chipman J. 2008. Schoeneich P, Reynard E, Pierrehumbert G. Remote Sensing and Image Interpretation. 1998. Geomorphological mapping in the John Wiley & Sons: New York Swiss Alps and Prealps. In Hochgebirgskartographie Silvretta '98. Kriz K Maillard B, Lambiel C, Martin S, Pellitero (eds.). Geographisches Institut: Wien, 145- Ondicol R, Reynard E, Schoeneich P. 2011. 153 The ArcGIS version of the geomorphological mapping legend of the University of Seijmonsbergen AC, Hengl T, Anders NS. Lausanne. Department of Geography, 2011. Semi-automated identification and University of Lausanne: Lausanne extraction of geomorphological features using digital elevation data. In Geomorphological Mather PM. 2004. Computer Processing of Mapping: methods and applications. Smith Remotely-Sensed Images. Wiley Blackwell: MJ, Paron P, Griffiths J (eds.). Elsevier: London London, 297-336 Oguchi T, Hayakawa Y, Wasklewicz T. 2011. Smith MJ. 2011. Digital Mapping: Data Sources. In Geomorphological Mapping: visualisation, interpretation and quantification methods and applications. Smith MJ, Paron of landforms. In Geomorphological Mapping: P, Griffiths J (eds.). Elsevier: London, 189- methods and applications. Smith MJ, Paron 224 P, Griffiths J (eds.). Elsevier: London, 225- Otto JC. 2008. Symbols for geomorphologic 251 mapping in high mountains for ArcGIS. Smith MJ, Clark CD. 2005. Methods for the Available at
Comparison of polynomial models for land surface curvature calculation. International Journal of Geographic Information Science 17 (8): 797-814
British Society for Geomorphology Geomorphological Techniques, Chap. 2, Sec. 6 (2013)