Using Google Earth Engine laboratory exercises in a college-level introductory physical geography course Part 1: Development

What is Google Earth Engine (GEE)?

GEE is a vast collection of free-to-use remote-sensing and modelling data of the Earth's lithosphere, biosphere, atmosphere, and hydrosphere. More than 40 years of remote-sensing imagery and datasets are available to the public. GEE describes itself as follows:

"Google Earth Engine is a cloud-based geospatial analysis platform that enables users to visualize and analyze satellite images of our planet. Scientists and non-profits use Earth Engine for remote sensing research, predicting disease outbreaks, natural resource management, and more. Your students can access this information to join the discussion and become data scientists themselves." (Google Earth Education, 2024a)

And further:

"Google Earth Engine combines a multi-petabyte catalog of satellite imagery and geospatial datasets with planetary-scale analysis capabilities. Scientists, researchers, and developers use Earth Engine to detect changes, map trends, and quantify differences on the Earth's surface. Earth Engine is now available for commercial use, and remains free for academic and research use." (Google Earth Education, 2024b)

The images and data are in raw form and accessing them requires the ability to code. However, once accessed, an HTML interface can be constructed and accessed by students via a link in a handout. In this way, GEE is similar to products such as ArcGIS.

Why use GEE in introductory classes?

Students should have the opportunity to get hands-on experience with unfamiliar concepts, using scientific resources directly. GEE provides students the opportunity to directly explore real, up-to-date data directly related to course topics. Faculty can connect their teaching and research, since many Earth scientists use GEE data in their scholarship. High school teachers can have their students use the same data as scientists do. The labs we provide are suitable for both secondary students as well as college students.

Prior educational use of GEE 

A cursory literature search for teaching with Google Earth yields many studies that address these issues, but the same is not true for teaching with GEE—they are not the same.

The use of GEE in postgraduate studies was described by Campos-Taberner et al. (2020), who found that GEE reduced computing time for remote sensing students in a master's degree program. Callejas et al. (2015) focused on impacts of GEE on coding self-efficacy between groups of STEM and non-STEM minority students. Juniors and seniors made up the STEM group, and the non-STEM group was populated by freshmen. All students used GEE to monitor environmental change as a means to learn coding. Callejas et al. (2015) reported that both student groups showed increased coding self-efficacy. These students were not in physical geography or Earth science classes.

Boopathi, Ganesan, and Naresh (2022) mentioned potential use of GEE by agriculture and water resource management students. Mathenjwa et al. (2022) described the educational potential of GEE as a tool for online teaching, notably for the development of OERs (Open Education Resources.) Their discussion was focused on more advanced remote sensing applications not suitable for the introductory college level.

Development of the lab exercises

Co-author Zheng created the labs. At first, he structured the exercises so that students were given lines of code to use for obtaining and using data. To change variables, students had to make changes to the code directly; first using Python, then in subsequent classes using JavaScript. This was not popular with students, who frequently shared their sentiments in class: "I'm so frustrated!" "I have no idea!" Zheng himself was frustrated that students were spending more of their cognitive time on coding than on content. In response, he created web page interfaces, where students could change variables, obtain data, and produce animations. In this interactive format, students can see the results of their work and not the code "behind the curtain." Students like looking at web pages, and all they need to bring is a laptop with internet access; any operating system works, whether Windows, Apple OS, Chrome, or even Linux.

Student & instructor experiences with the HTML format 

We saw high levels of engagement and enthusiasm. Students would talk to each other and ask questions that came from genuine interest in the concepts. Sometimes students got creative in their queries and changed variables in unprompted ways to generate interesting outputs that provided enhanced learning opportunities. As the instructor, Zheng found that he had an easier time troubleshooting and monitoring student progress as he moved about the room. The labs are designed such that in order to generate the correct outputs, students have to understand the concepts. Grading was more efficient, since a large part of grading these labs is verifying that students generated the correct outputs.

Zheng's scientific research focuses on greenhouse gases and climate change. The labs he created for climate and climate change use the same GEE data he uses in his research, notably the intermodal comparisons, which are also used by the Intergovernmental Panel on Climate Change (IPCC).

About the introductory physical geography course 

"Introduction to Physical Geography" (GEO 105), is taught as a face-to-face or hybrid three-credit hour combined lecture/laboratory course that meets for one hour fifty minutes twice per week for 16 weeks. The course is also taught asynchronously online in four- and eight-week sessions. The combined lecture-lab format allows for flexibility in structure and topical sequence. Zheng teaches GEO 105 by first introducing students to a topic with a lecture, and then following that with a lab exercise. Labs can be during the same class period as the lecture, or in a later meeting. Zheng gives four non-cumulative exams over the course of the semester, drawing content from both lectures and labs. The topical outline is shown below.

Nature of physical geography 
Atmospheric energy and matter 
Atmospheric motion 
Atmospheric moisture 
Exam 1

Weather systems and severe weather 
Atmosphere-Ocean-Cryosphere interactions 
World Climates 
Water resources 
Exam 2

Understanding landscapes 
Plate tectonics and regional features 
Volcanoes, deformation, and earthquakes 
Weathering and mass wasting 
Streams and flooding 
Exam 3

Glaciers and glacial landforms 
Coasts and changing sea levels 
Soil 
Ecosystem and biogeochemical cycles 
Biomes 
Exam 4/Final Exam

All GEO 105 instructors must meet the following Student Learning Outcomes (SLOs) as designed and approved by four separate committees at the department, college, university, and faculty senate levels in accordance with institutional curricular policy. The SLOs are:

1. Analyze the interrelationships of the Earth's physical systems.
2. Describe the relationships between the sun and the Earth and how they produce day and night and the four seasons.
3. Identify weather and climatic controls.
4. Analyze the interrelationships of the atmosphere, hydrosphere, and lithosphere variables that produce the daily weather.
5. Categorize how long-term daily weather data is analyzed to produce climatic types.
6. Explain the distribution of global climates by analyzing the importance of latitude, land and water contrasts, global wind patterns, and global ocean currents.
7. Compare the relationships between the distribution of global climates and the major soil types and vegetation zones.
8. Describe the geologic processes that operate within and above the Earth and how they are related to plate tectonics.
9. Describe the erosional, transportational, and depositional capabilities of running water and continental glaciers and understand how these activities produce sequential assemblages of topographic features on the Earth's surface.

We found that each objective could be addressed by GEE labs. In fact, all SLOs were at least indirectly addressed, and eight out of nine were directly addressed. Twelve percent of GEE lab content was outside of the listed objectives.

Recommendations

Our recommendations apply to both college and high school students and teachers. First, do not have students use code in the introductory classes. We observed the highest levels of frustration and disengagement when students had to enter, annotate, and debug script. Second, incorporate and intersperse GEE labs into lecture. GEE presents outstanding opportunities for guided inquiry. Even if a class is not structured in a combined lecture-lab format, it is still possible to introduce, animate, and narrate concepts if students have devices with them. Third, if an instructor has the requisite coding skills, they can modify the provided lab exercises or create new ones; let the data available on Google Earth Engine guide your explorations. Instructors who make new GEE exercises or extensive modifications to the ones we provide should be prepared to invest significant preparation time up front.

Future work

We intend to conduct quantitative analyses of lab pedagogies, in which GEO 105 sections that use GEE labs are an experimental group, and sections using other resources are a control group. We will also analyze how our GEE exercises can be made fully accessible to students and instructors with disabilities and how they can be informed by the principles of Universal Design.

Accessing the video demonstration and the GEE materials 

Part 2 of this article demonstrates two lab exercises and includes links to all twenty-two. The lab exercise materials we provide for other educators are PDFs containing instructions and questions to answer, which students access and complete electronically. These exercises also contain links to the GEE website resources. The GEE websites are hosted by Google Earth Engine, and therefore do not require extra resources for instructors.

References

Boopathi, R., M. Ganesan, V. Naresh. 2022. Know Your Daily Rainfall in Any Location in India- A Web-Based Approach Developed in Google Earth Engine. Proceedings of International Conference on Innovative Technologies for Clean and Sustainable Development (ICITCSD – 2021). doi: https://doi.org/10.1007/978-3-030-93936-6_2

Callejas, I.A., L. Huang, M. Cira, B. Croze, C.M. Lee, T. Cason, E. Schiffler, C. Soos,  Z. Wang. Use of Google Earth Engine for Teaching Coding and Monitoring of Environmental Change: A Case Study among STEM and Non-STEM Students. Sustainability 2023. doi: https://doi.org/10.3390/su151511995

Campos-Taberner, M., F.J. García-Haro, B. Martínez, S. Sánchez-Ruiz, and M.A.  Gilabert. 2020. Google Earth Engine as cloud computing platform in remote sensing postgraduate studies. INTED2020 Proceedings.

Google Earth Education, 2024a, Planetary-wide analysis on Google Earth's Cloud. Accessed June 18, 2024. https://www.google.com/earth/education/tools/google-earth-engine/

Google Earth Education, 2024b, A planetary-scale platform for Earth science data & analysis. Accessed June 18, 2024. https://earthengine.google.com/

Mathenjwa, S., M. Lugoma, L. Maduna, and M. Ilunga. 2022. An online open educational resource for surface water monitoring in remote sensing using Google Earth Engine. Proceedings, Anadolu University 5^th International Open & Distance Learning Conference.

Authors

^aGeography & Environmental Studies, Central Michigan University, Mount Pleasant, USA [link https://orcid.org/0000-0001-5163-751X

^bGeography & Environmental Studies, Central Michigan University, Mount Pleasant, USA https://orcid.org/0000-0002-2358-2416 

*Corresponding author contact: feig1ad@cmich.edu; +1.989.774.1166