Computational Inquiry into a Hillslope Surface Model

Risa Madoff
University of North Dakota-Main Campus,
Author Profile


By using (x, y, z) data imported from repeat scans of a terrestrial LiDAR, students learn how to conceptualize a natural surface by using MATLAB to model it and to model change. Because the model has a real physical grounding, students learn to inquire into natural processes by querying physical parameters and functions in MATLAB. In this way, too, they experience experimental reasoning and inquiry in science.

Used this activity? Share your experiences and modifications

Learning Goals

Students should learn how to assess lines of code for their roles in a program and what is being done to the data in the course of making surface plots of nonuniformly sampled data. They learn to think about overlying surfaces and how to inquire into how to use the data to understand changing surface conditions through time. MATLAB is being used as an inquiry tool to investigate hillslope surfaces. At the same time, students learn to experiment with different functions and come up with questions about inquiring into surface processes that they would unlikely have come up with by looking at photographs and maps or landscape models generated by someone else. All of the higher skills can be captured by this pedagogy – critical thinking, computation, analysis of data (averages, min and max erosion, spatial analysis of sediment relocation), synthesizing the results within the framework of diffusion, and modeling a real natural feature as well as real change. The goal is that by the instructor providing some guidelines and support as to what is needed for steps along the way, student will find where to look within MATLAB, experiment with possibilities and experience success both in programming and understanding surface modeling. Ideally, students should acquire the point cloud data themselves and they would need to learn to operate the laser scanner, but this is not essential. However, students are asked to put together portfolios of modules and present their ideas in class and give a presentation based on a novel extension they add to the exercise, such as a new analysis not given in class.

Context for Use

The exercise is given more as a method of teaching, than as a code to be run for a certain visualization. It is intended as a combined in-class discussion and exercise and take-home thought experiment. Depending on the level of the class, it can take 1-3 class sessions, but it can be expanded. The educational level would be for upper-level undergraduates, graduate students, and those willing to spend time outside of class and independently learning MATLAB. It does not assume programming knowledge and the focus is not about writing code either, but it does require a willingness to think about complex ideas, to experiment with code, and learn what the lines of code are doing. Class size probably should be limited to up to 10 to 15, in order for an instructor to be able to help students during a class session. Instructors from any size 4-year college or university could use the exercise depending on the interest level of the student body. The exercise assumes that students have been acclimated to the layout of the MATLAB windows, functioning of the menu, and to a basic foundation of the program.

Description and Teaching Materials

An Instructor worksheet is provided with the sets of codes filled in that the students would need to find on their own after a class discussion about reasoning through what is going to be needed to model the data set they have. As students build the lines of code, they are asked to record what each line is doing. Supplement questions are provided at the end to further the integration of conceptualizing surface change of a natural land surface with lines of code that test parameters that produce possible results applicable to a real surface in the past, present or future.
Instructor Guide for Using MATLAB for Earth Surface Modeling Inquiry (Acrobat (PDF) 244kB Oct4 16)

Teaching Notes and Tips


-They can explain the code that is either given to them or that they generate to perform a needed step in the modeling
-Query their own code for an expanded analysis
-Class presentation on a different model not discussed in class, using the inquiry technique applied during the class
-Modeling portfolio collection

References and Resources