Geomorphology and the importance of mapping

What’s Geomorphology? Geomorphology is understanding of landforms and their genesis.  It focuses on the land surface and the system process that leads to the shaping of the Earth.  It is a physical science that looks to explain how the world formed to what we see today.  Evans (2012) reviews the definitions of geomorphology, which are surprisingly consistent, but he raises the question of how innovations in geomorphometry (the science of terrain analysis, see ISG) is changing geomorphic mapping.  Changes in geomorphic mapping can have profound impacts on the science of geomorphology, because the foundation of geomorphology is observation and then explanation of Earth surface processes.  When the observation capabilities are enhanced, the foundation of explanation can be greatly altered.  This can lead to a paradigm shift in how we view the creation of land surfaces (Baker and Teidale, 1991).

Geomorphic mapping considers the genesis of landforms, not just the landforms themselves (Dackombe and Gerdiner, 1983). Differing from physical geographic and geologic mapping, it goes more in-depth looking at not just the landforms but mapping the ‘genetics’ of the landforms.  In many ways it is the foundation of geomorphology, providing the data and observations needed for the scientific inquiries to take place.  Geomorphic mapping can occur from the fieldwork scale up to the satellite observation scale.  The concept of land surfaces begins at the human scale or 1.5 meter (Evans 2012), in which people can observe landforms in the real world, and mapping requires fieldwork for proper interpretation.  Geomorphometry and remote sensing has revolutionized geomorphic mapping, in that it allowed for observations in mere minutes what would take weeks in the field to collect, but it does not replace fieldwork.  The Kosi Megafan is an example of how Landsat imagery clearly shows patterns of paleochannels marking a progressive westward shift of the Kosi River from its 1736 position to the eastward edge of the fan (Dackombe and Gerdiner, 1983). Products like Google Earth allows for fly through of the landscape, integrating photometric observation with geomorphic mapping.  Digital Elevation Models (DEM) has also played a major role in geomorphic mapping. They allow for virtual transects to be made, slopes and aspects to be calculated, and 3d visualizations.   DEM analysis has also led to further abilities to extract in automated ways landforms from the surface models (e.g. levees see Sounny-Slitine, 2012). 

Geomorphology is a powerful science in that it integrates findings into the context of the environment. It allows for questions to arise that would not come up just looking at a landform.  Through integration of many datasets geomorphologist are able to understand the evolution of the landscape.  This understanding of the landscape is fundamental to understand other aspects of the environment, like the ecology, natural hazards, and conservation.  The surface of the Earth is where our lives take place. It is literal right beneath our feet and is one of the first curiosities we have as children. Why do our surroundings look the way the look? Surprisingly we know so little about it or its sensitivity to change (Gutiérrez, 2012). Mapping is a tool to understand it more, but only hard geomorphology can explain why the maps look they way they do.  While the technology of observation has advanced greatly, the science behind geomorphology is prime for a new breakthrough of advancements.  It is time to capitalize on the new observations and field technique capabilities to answer fundamental questions about the Earth surface.

WORKS CITED

Baker, V. R., & Twidale, C. R. (1991). The reenchantment of geomorphology. Geomorphology, 4(2), 73-100.

Dackombe, R. V., & Gardiner, V. (1983). Geomorphological field manual. London: Allen & Unwin.

Evans, I. S. (2012). Geomorphometry and landform mapping: What is a landform? Geomorphology, 137(1), 94-106.

Gutiérrez, E. M. (2012). Geomorphology. Boca Raton, Fla: CRC.

International Society from Geomorphometry (ISG), see website http://www.geomorphometry.org/

Sounny-Slitine, M.A. (2012). Geomorphic and anthropogenic influences on hydrological connectivity along the lower Mississippi River. (Master’s Thesis). University of Texas at Austin, Department of Geography and The Environment, under supervision of Dr. Edgardo Latrubesse.