Smith / Griffiths / Paron Geomorphological Mapping

Methods and Applications
1. Auflage 2011
ISBN: 978-0-444-53536-8
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band Volume 15, 610 Seiten

Reihe: Developments in Earth Surface Processes

Geomorphological Mapping: a professional handbook of techniques and applications is a new book targeted at academics and practitioners who use, or wish to utilise, geomorphological mapping within their work. Synthesising for the first time an historical perspective to geomorphological mapping, field based and digital tools and techniques for mapping and an extensive array of case studies from academics and professionals active in the area. Those active in geomorphology, engineering geology, reinsurance, Environmental Impact Assessors, and allied areas, will find the text of immense value. - Growth of interest in geomorphological mapping and currently no texts comprehensively cover this topic - Extensive case studies that will appeal to professionals, academics and students (with extensive use of diagrams, potentially colour plates) - Brings together material on digital mapping (GIS and remote sensing), cartography and data sources with a focus on modern technologies (including GIS, remote sensing and digital terrain analysis) - Provides readers with summaries of current advances in methodological/technical aspects - Accompanied by electronic resources for digital mapping

Autoren/Hrsg.

Smith, Mike J.

Griffiths, James S.

Paron, Paolo

Leseproben

Developments in Earth Surface Processes, Vol. 15, No. Suppl C, 2011 ISSN: 0928-2025 doi: 10.1016/B978-0-444-53446-0.00002-1 Chapter Two Old and New Trends in Geomorphological and Landform Mapping Herman Theodoor Verstappen International Institute of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, The Netherlands 1. THE ADVENT OF GEOMORPHOLOGICAL MAPPING
Geomorphological mapping began about a century after the advent of geological mapping and the standardisation of a legend system (Finkle, 1988). The earliest geomorphological map was probably made by Passarge (1914) on the Stadtremba 1:25,000 topographic map sheet in Germany. The legend of Passarge’s map differed from modern examples because it did not encompass all aspects of geomorphology, and it emphasised mainly descriptive morphographic features and metrical elements. It did not receive much attention at that time, and geomorphologists tended to produce ‘sketch’ maps at small scales that were either largely structural or physiographic-pictorial (Raisz, 1931). Most of the maps from this early period dealt with only one phenomenon (e.g. river terraces) and left large portions of the map sheet blank. The development of modern concepts of geomorphological mapping started in the early 1950s. In Switzerland, Helbling (1952) included a geomorphological map in his Ph.D. thesis on the Sern valley and thereafter Annaheim (1956) took an interest in the subject in that country. The greatest developments came from Poland where Klimaszewski (1956, 1963) launched a countrywide 1:50,000 scale geomorphological survey together with Galon (1962) who specialised particularly on the Polish lowlands (Figure 2.1). Then, other European countries such as France, Germany, and Switzerland developed similar maps. At the beginning, emphasis was mainly focused upon detailed mapping at scales ranging from 1:10,000 to 1:100,000, and methods and legends for medium- and small-scale mapping followed soon after. Figure 2.1 Detailed geomorphological map of an outwash landscape of the Poznan stage, Weichselian glaciation, NW Poland. Scale 1:50,000 (Galon, 1962). The legend of the detailed geomorphological map of northern Poland includes 15 landform categories. This example shows the outwash plain (IV.10 – screen of small circles) at places surrounded by periglacial foot slopes (VII.29) and dissected by small V-shaped valleys (IX.35). It is separated by an escarpment of a height of 10–20 m (XV.57) or more than 20 m (XV.58) from a peat-filled valley (XIII.5 – screen with dashes), where a river and some lakes (XV.60/61) occur. Contour lines and spot heights (XV.62) complete the map. Since the essence of geomorphological mapping is the representation of the terrain configuration, landforms are the cartographic units to be distinguished, regardless of the mapping scale. However, while in detailed mapping geomorphological processes are emphasised, the underlying structural factors in landform development became important particularly in medium- and small-scale mapping. This explains why morphostructure was advocated as the highest category of landform classification especially by geomorphologists of the former Soviet Union where small-scale geomorphological mapping was the trend (Simonov et al., 1960, in St-Onge, 1964; Bashenina, 1972). It is evident that making a small-scale geomorphological map from detailed maps does not only amount to data reduction and generalisation but also requires a different approach. Most analytical geomorphological maps are complex as a result of the diversity of the data to be included, such as morphography, morphogenesis, morphodynamics, morphometry, chronology, and lithology. This has led to the development of a great variety of legends in different countries on the basis of which some common concepts gradually emerged. 2. THE DIVERSITY OF LEGENDS
When comparing early geomorphological maps and their legends, one is struck by the diversity of the then prevailing concepts and cartographic conventions. This results in part from the terrain configuration of the surveyed areas. For example, legends for lowland areas tend to be simpler than those required in hilly and mountainous terrain and the need for coloured symbols is thus limited (Figure 2.1). That simple legends may, to a certain extent, also be feasible in areas of relief is shown in Figure 2.2 which depicts marine terraces in southern Italy (Verstappen, 1983). Figure 2.2 Example of a black and white geomorphological map in Savuto Valley, Italy. Scale 1:100,000 (Verstappen, 1983). However, the use of colours is inevitable for the cartographic representation of all types of geomorphological information. The coloured area symbols are at present commonly used for indicating morphogenesis, as proposed first by Klimaszewski (1956) in Poland (Map 2.1) and Joly in France. Gellert and Scholz (1960) produced maps of the lowlands of the former Deutsche Demokratische Republik (DDR) with coloured area symbols indicating the chronological sequence of landform development (Map 2.2). This was a logical option because most of the landforms occurring dated from several Pleistocene glacial periods and were easily distinguishable. The advantage of this method was that it concurred with geological maps. However, this legend was not universally applicable. Another option is to relate coloured area symbols to lithology as applied by Tricart (1955, 1969, 1972) in France. Map 2.1 Detailed geomorphological map of Poland. Two examples from the area of Southern Poland (1:25,000–1:50,000) (Klimaszewski, 1956). The electronic version is available at http://www.appgema.net/. Map 2.2 Morphogenetic map of the former DDR. Sheet Berlin (Nord) 1:200,000 (Gellert and Scholz, 1960). The electronic version is available at http://www.appgema.net/. The legend developed by Klimaszewski (1956) was first used in the denudational hills and mountains of southern Poland. It was therefore considerably more complex than the one used by Galon (1962) farther North. Klimaszewski introduced landforms as the highest category of his legend and gave further information on geomorphological processes and chronology. The legend of the geomorphological map of western Germany [then Federal Republic of Germany (FRG)], introduced by the German Research Council, is of comparable complexity (Leser, 1974). At the Centre for Applied Geomorphology (CGA) in Strasbourg (France), emphasis was put on lithology, for which the coloured area symbols were used. This was justified because of the obvious relations that exist between rock types, landforms and geomorphological processes. Morphochronology was also included (Tricart, 1955, 1969; Bourdiec et al., 1963). Tricart produced many maps of this type, placing the emphasis on the granulometry and chemical/mechanical characteristics of the rocks and superficial deposits. He used line symbols in various colours for indicating chronology. Joly (1963) proposed a slightly different approach for the compilation of the detailed geomorphological map of France at the scale of 1:50,000 (Tricart, 1970), with a legend depicting superficial deposits, their thickness and granulometry. Colours were used for the various morphogenetic systems with different hues showing successive generations of landforms. A decimal system was devised for the taxonomic classification of these landforms. In the legend used in Hungary (Pecsi et al., 1962; Pecsi, 1964), the coloured area symbols were used for distinguishing the major morphogenetic landform types. However, lithological influences were also stressed, while the processes were indicated by screens. An interesting contribution is that the chronology is indicated by ciphers. This is a very flexible solution because the ciphers can simply be omitted where the age of the landforms is not exactly known. The legends used in the former Soviet Union were essentially morphogenetic (Bashenina, 1972). The coloured mapping units thus represent major landform types and complexes called mesoforms. The chronology was also emphasised and was indicated by density of colours. Lithology was a minor component as well as morphometric information. Morphostructures were emphasised in medium- and small-scale maps. A map of Quaternary surface deposits was added where their thickness exceeded 10 m. Morphometric data rank high in a number of Belgian geomorphological maps next to the morphogenetic information (Macar et al., 1960). The same principles were applied to the legend of the geomorphological map of the Netherlands at the scale of 1:50,000 (Maarleveld et al., 1974; Van Noord, 1993). This map was complementary to the earlier existing geological and soil map series at the same scale and this explains the strong emphasis on morphometry. The coloured area symbols were allocated to eight major relief classes, defined by slope gradient and length and subdivided into 18 relief types according to relief amplitude. Morphogenesis and past and present processes were listed in the legend where they are represented by screens. 3. THE NEEDS FOR...