Measuring Coastal Change

Carla Grandy
City College of San Francisco
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Students analyze a time-series of aerial photographs of coastal areas to describe changes in beach width and depositional and erosional features over several decades.

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This assignment is designed for an introductory level physical geography lecture or lab though it could easily be modified for an upper level undergraduate geomorphology or coastal geology course.

Skills and concepts that students must have mastered

Students need a basic understanding of coastal processes and some experience or an introduction to air photo analysis and converting measurements made on aerial photographs to actual distances.

How the activity is situated in the course

This is a stand alone exercise for a coastal geomorphology section.


Content/concepts goals for this activity

Goals include: analyzing aerial photographs, and understanding coastal evolution.

Higher order thinking skills goals for this activity

Analysis of data and synthesis of ideas

Other skills goals for this activity

working in groups, understanding map scales

Description of the activity/assignment

Students analyze a time-series of aerial photographs of beaches to describe changes in beach width and depositional features over several decades. This activity can be done with oblique aerial photographs to give a qualitative description of beach width changes, the location of dunes fronts, change in river position, changes in development density, and change in vegetation cover. Vertical aerial photographs can also be used and students can actually measure beach and dune widths over the time-series to quantify changes. If both oblique and vertical photographs are available, they can compare the two perspectives and perform both descriptive and quantitative assessments.
Designed for a geomorphology course
Designed for an introductory geology course
Uses online and/or real-time data

Determining whether students have met the goals

Students are evaluated on the data that they collect (that it makes sense) and on their interpretation of events.

More information about assessment tools and techniques.

Teaching materials and tips

Other Materials

Supporting references/URLs

California Coastal Records Project
U.C. Santa Barbara Map and Imagery Library (
U.C. Berkeley Catalog of Aerial Photography (
U.S.G.S. (
California Spatial Information Library (