Unit 3.2: Landforms and Remote Sensing

Introduction

In this unit, geomorphic environments and the processes that can move and shape them are explored to learn about the links between landforms, soils, and the Critical Zone. The fundamentals of geomorphology are considered along with a somewhat detailed analysis of fluvial, eolian, glacial/periglacial, karst and coastal landforms and processes. In this unit, you will:

• comprehend a soil catena and the influence of slope and aspect on pedogenesis
• distinguish and assess some features and processes characteristic of five generalized geomorphic environments
• apply knowledge gained to find remotely sensed imagery, specifically aerial photographs, for a study site cleared with your instructor

Unit 3.2: Landforms

Part 1 - Geological Processes

Pre-class

• Read (individually) Chapter 9 in Birkeland, P. W. (1999). Soils and Geomorphology (3rd ed.). New York: Oxford University Press.
  • Make sure you understand the idea of a soil catena and (re)consider the effects of topography on the CZ – think about how the feed-through reactor and chemical weathering fluxes might operate in a select study site and how they might vary between nearby environments.
• Read (groups) the information selected from the 5 landscape categories outlined below: fluvial, eolian, glacial/periglacial, karst and shoreline processes and landforms. Each group will pre-read and report on one of the 5 landscape categories outlined above. The information covered here will set the stage for an in-class discussion as well as for activities in the second day of class in this unit.

Fluvial Landforms and Processes:

• This site provides a good general overview of fluvial landforms and processes, beginning with the hydrologic cycle and surface runoff. The site then provides a characterization of the parts and types of rivers, drainage patterns, fluvial processes of erosion, deposition, saltation, solution and suspension, and erosional and depositional landforms.
  • Wikipedia: Fluvial Landforms and Processes
• This hyperlink overlaps somewhat with the one above. While studying this site, do not concern yourself with the details of specific drainage basins unless they are of interest to you. You can peruse the section on river types and drainage basin patterns for more detail than is available above. Do read the short sections on structure and tectonics, and paleochannels.
  • NASA, Geomorphology Chapter 4: Introduction to Fluvial Landform
• Good images of stream channel types and features can be viewed by following this hyperlink:
  • Pidwirny (2006) Fundamentals of Physical Geography eBook, Chapter 10.z: Fluvial Landforms

Eolian processes and landforms:

• Study this reference to learn about eolian processes and landforms. Be sure to leave the site having grasped concepts covering the relationship between velocity, entrainment and transport, and the variety of erosional and depositional eolian landforms.
  • Pidwirny (2006) Fundamentals of Physical Geography eBook Chapter 10.ah: Eolian Processes and Landforms
• For more detail and good imagery of dune fields check out the Pattern Indicators in:
  • USACE (1991) Remote Sensing Field Guide - Desert(PDF, 363 pp; begin on p. 106 noting that some imagery is barely legible)

Glacial/periglacial processes and landforms:

• Use this site to review the causes of glaciation and glacier motion. Then review the anatomy of and types of glaciers, glacier erosion, sediment transport and deposition, and the resulting continental and alpine landforms.
  • Ritter (2006) The Physical Environment, Ch.19, Glacial Systems
• Periglacial processes and landforms are described at the following web site focusing on permafrost, freeze-thaw weathering, ground ice, mass movement, and the erosive processes of gelifluction, wind and flowing water.
  • Pidwirny (2008) | Encyclopedia of the Earth: Periglacial Processes and Landforms
• For additional information, mostly review but with nice imagery, follow this hyperlink:

Karst processes and landforms:

• Unique landforms and patterns of drainage called karst or karst topography primarily form in temperate to tropical regions, though they are found in arid and polar regions too. The common feature shared by all karst landscapes is that they are underlain by chemical sedimentary rocks particularly susceptible to dissolution, carbonates and/or evaporites. The landforms result mostly from chemical weathering of the host rock and the progressive integration of subsurface cavities, though collapse into solution cavities can also be important. Karst landscapes are often dominated by underground drainage networks that interrupt and capture surface water flow. Interestingly, a new type of karst, thermokarst, is now studied in high latitude regions subjected to global warming. As permafrost thaws, removing subsurface ice that otherwise provides structural support for the surface, surface environments degrade and collapse in ways quite similar to those observed in classical karts landscapes. For a relatively succinct definition of karst, from the Canadian perspective, follow this hyperlink:
  • Karst Landform
• Of the karst-forming rocks, the carbonates (dolostone and limestone) are much more abundant than evaporites (mostly deposits of gypsum and anhydrite), therefore karst landscapes are most often found in regions underlain by carbonate rocks. The following Web site will help you learn more about limestone karst, including information on the relationship between lithology, porosity, permeability and karstification, the distribution of karstlands in the United States, the driving mechanics of karst processes, and links between surface water flow, aquifers and groundwater.
  • Lemke (2013) UWSP, Karst Processes (link down)

Shoreline processes and landforms:

• To learn about shoreline processes and coastal evolution, wave refraction and erosion, sediment transport and deposition, and submergent and emergent coastlines through a series of schematic diagrams, follow this hyperlink:
  • Tulane: Shoreline Processes and the Evolution of Coastal Landforms
• A more basic review with colorful images of wave action, coastal processes, and images that help to identify coastal classification schemes can be viewed at:
  • Ritter (2006) The Physical Environment, Ch.21, Coastal Landforms and Processes
• The following two hyperlinks lead to other reviews of coastal processes and landforms, as well as wave refraction, erosion, and deposition, importantly with nice images (from: Pidwirny (2006) Fundamentals of Physical Geography eBook)
  • Chapter 10.ac, Coastal and Marine Processes and Landforms
  • Chapter 10.ac_2, Coastal and Marine Processes and Landforms: Wave Refraction, Erosion, and Deposition
• More information on classification, with nice imagery, can be studied at:
  • GeoBytes: Coastal Erosion Features (blog, student made, slow videos)
• Review as a class (30 minutes)
• Fluvial/Deltaic/Coastal Landforms and
• Karst/Lacustrine/Aeolian/Glacial Landforms

In-class

Discussion of reading and presentations

• Each group will present on the landscape areas and processes.
• Class discussion focused on:
  • Soil catena
  • Role of topography
  • Characteristic landforms

Part 2 - Remote Sensing Imagery

In-class

National Geo-PhotoFinder Activity

• Your instructor will introduce you to remote sensing and aerial photography by utilizing a class demonstration and videos. Then you will be introduced to the homework exercise that you will complete after class.

Homework

• In this exercise you will explore and manipulate EROS resources related to satellite and aerial photography of a wide variety of landscapes introduced above.
  • Activity Worksheet: GeoPhotoFinder activity (Microsoft Word 40kB Dec23 16)

Additional Resources

Links found the Geo-PhotoFinder Activity

• EROS Data Center
• Color Landform Atlas of the United States
• Flash Earth
• Principles in Remote Sensing
• Penn Pilot
• TerraServer