Learning About Dams and Reservoirs Using ArcGIS Online
Your Name: _________________
Summary
This activity uses ArcGIS Online, a
Web-based
Geographic
Information
System
(GIS)
(www.arcgis.com) as a tool for
analyzing the geography and
science of water from a spatial
perspective. This activity focuses
on dams and reservoirs.
Detail
This activity is written for upper
secondary/university level but
can be used at the lower
secondary level, and can even be
modified for primary levels. It can
be used in formal or informal
Dam and reservoir in China shown in ArcGIS Online. Examining
educational settings and in an
dams and reservoirs using ArcGIS Online is included in this activity.
independent or whole-class
format. Time estimated: 1 class
period of 50 minutes. No previous experience with GIS is necessary but (1) the geographic perspective is
important, and (2) a background in the topic investigated would be helpful; at a minimum, a short
discussion on the processes and phenomenon studied in each investigation should be held at the
beginning; such as “Why are dams and reservoirs constructed? How do dams and reservoirs affect the
landscape, the economy, and the environment?”
Computer requirements: Web browser, Internet connection. Can be run in a computer lab setting, with
dedicated lab computers or students bringing their own tablets/laptops/devices, or with 1 computer in
front of the class with a projector.
Introduction
Water is a spatial subject: It can occur in solid, liquid, and gas phases on our planet and can easily move
between these three states. It moves through oceans, rivers, wetlands, and glaciers, and through the
hydrologic cycle at different rates. It is affected by long-term climate, everyday weather, hurricanes,
landforms, and air pressure. It has been channeled into settling ponds, water treatment plants, fields,
irrigation ditches, drainage ditches, canals, reservoirs, and through many other means by humans. It
acts as a change agent above, on, and below the surface of the Earth, affecting such phenomena as crop
Learning About Dams and Reservoirs Using ArcGIS Online - Page 1 of 3
Author: Joseph J. Kerski – jkerski@esri.com
Copyright © 2012, Esri. http://edcommunity.esri.com
yields, aquifers, erosion, floods, stream sediment, soil chemistry, weathering, and much more. It
operates on a scale from local to global. Because water exists, moves, and acts at different scales and
affects so many other phenomena, the geographic perspective is critical to understanding it. And, GIS is
a very useful tool in which to study water in all of its forms, processes, and aspects.
Watch the movie “geographic reflections on water”: http://youtu.be/ntJvY4LixqQ
Name 3 connections between water and geography.
Because of these and a whole host of other factors, the geographic perspective is critical to
understanding water. GIS allows the geographic perspective to be applied to the study of water, and
ArcGIS Online provides a toolkit and rich set of data that allows you to study water right away.
ArcGIS Online Investigation
This investigation uses ArcGIS Online, on http://www.arcgis.com.
Investigating Dams and Reservoirs Along Rivers
Do some research on the following topic: Why are dams and reservoirs constructed? Name at least
three different reasons.
At ArcGIS Online (http://www.arcgis.com), click on “map.” Change the basemap to Light Gray Canvas.
Find the following rivers: The Amazon, the Nile, and the Yangtze. Zoom in and pan along each river.
Can you find dams and reservoirs along each river? If so, how many can you find, and where are they
located?
What is the average distance between each dam? Show your work.
What impact do dams have on aquatic life and water quality? What impact do they have on electrical
power generation? What impact do they have on local and regional irrigation for crops? What impact
do they have on providing water for municipal and industrial use?
Zoom to the Hoover Dam on the Colorado River, southeast of the city of Las Vegas, Nevada. You can
search on “Boulder City, NV” and then pan to the northeast to find the dam.
What two states are on either side of the dam? What river is the dam on? What direction is the river
flowing? How can you determine the river’s direction? What reservoir is backed up by Hoover Dam?
What famous canyon is upstream from this reservoir? What is the length of Hoover Dam in feet and in
meters? What is the areal size of the reservoir in square miles and square kilometers?
What shape does the dam have? Do some research to find out why it has the shape it has. Do some
research to determine: When the dam was built, why it was built, and how much concrete is in the dam.
Learning About Dams and Reservoirs Using ArcGIS Online - Page 2 of 3
Author: Joseph J. Kerski – jkerski@esri.com
Copyright © 2012, Esri. http://edcommunity.esri.com
Zoom to the Aswan Dam by searching on “Aswan, Egypt.” What river is the Aswan Dam on? What
direction is it flowing? Compare the surrounding terrain at Aswan vs. that surrounding the Hoover Dam.
What are the differences and similarities? Do some research to determine the following: Name three
benefits provided by the Aswan Dam, and three unfortunate consequences that the dam caused.
One of the most controversial projects has been the Three Gorges Dam in China. Search for and zoom
to Yichang, China. Zoom out a bit and experiment with different base maps. What river are you
examining? Pan 18 miles (27 km) northwest of Yichang to the dam site. Describe the physical
environment of this area. How would the physical environment pose a challenge to the construction of
the dam? Do some research on Three Gorges Dam. Name at least two reasons why this dam has been
so controversial.
Choose another major river and report on how many dams you found along it, and calculate the average
distance between dams.
Do some research to find the world’s three largest dams. In which countries are they located? What
rivers are they on? Is Hoover Dam or Three Gorges Dam one of the three largest? Zoom to each of the
three largest. Measure the length of each dam. Measure the areal size of the reservoirs formed from
each dam.
Conduct some research on the world’s three tallest dams. Are they the same as the three largest dams?
Zoom to each and indicate the countries in which they are located and the rivers they are on.
If time permits, add pushpins to your map for the three largest and three tallest dams of the world, save
your map, and share your map.
Synthesis
Name three things you have learned about dams and reservoirs through any of the above investigations.
Name three things you have learned about GIS through these investigations.
How has the spatial perspective about dams and reservoirs influenced your understanding of them?
If time permits, use the presentation mode in ArcGIS Explorer Online to create a presentation of your
own choosing where you explain what you have learned about a specific aspect about dams and
reservoirs. Give your presentation to your peers, save it, and share it with others.
Additional Explorations
You have explored a few aspects of dams and reservoirs from a spatial perspective, but much more
could be done. Write your own question about dams and reservoirs, investigate it, and answer it! 
Learning About Dams and Reservoirs Using ArcGIS Online - Page 3 of 3
Author: Joseph J. Kerski – jkerski@esri.com
Copyright © 2012, Esri. http://edcommunity.esri.com