Using ArcGIS to Study the New Lakes in the Toshka Basin in Egypt and Evaluate Egypt's New Valley Project

Barbara and David Tewksbury
Hamilton College
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In this assignment, students use ArcGIS to analyze the new lakes that have formed in the Toshka Depression, Egypt as a result of overflow from Lake Nasser and use their analyses to evaluate the wisdom of the plan to bypass the Toshka Lakes in developing the New Valley Project for irrigation in the Western Desert of Egypt.

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This exercise is part of an introductory geology course called Geology and Human Events in Africa and the Middle East. The course focuses on the underlying influence of geology and geologic processes on human events.

Skills and concepts that students must have mastered

Students must have basic ArcGIS skills and be able to work with DEMs in ArcMap, create and manipulate hillshades, manipulate layers in ArcGIS, and create map layouts.

How the activity is situated in the course

This exercise takes place about half way through the course.


Content/concepts goals for this activity

Students will consolidate concepts related to desert hydrogeology, water use in a dry climate, and hydropolicy.

Higher order thinking skills goals for this activity

Students will determine what questions they want to have answers to and how to do the GIS analyses to find the answers. Ultimately, they will use the analyses that they have done to independently evaluate Egypt's New Valley Project.

Other skills goals for this activity

Students will practice GIS skills learned in previous assignments.

Description of the activity/assignment

In 1978, the Egyptians constructed a canal known as the Toshka Spillway from Lake Nasser into a low area to the west to allow spillover of Lake Nasser water. Despite the fact that the spillway was created in 1978, it wasn't until the late 1990s that Lake Nasser actually filled up to the level of the spillway canal and the overflow lakes began to form. In November of 1998, US astronauts orbiting in the Space Shuttle noticed the lakes filling for the first time, and they have had water in them ever since.

Egypt has embarked on a long-term and far-reaching irrigation plan to create habitable land away from the Nile River Valley. The Toshka Lakes are not, however, a formal part of the project. One of the main points of the exercise is to have students use both their knowledge of Saharan hydrogeology and GIS analyses to evaluate whether the Egyptians are wise not to use the lakes as part of the proposed system of water distribution.

In this exercise, students download and prepare their own SRTM DEMs and learn how to determine areas and volumes using ArcGIS. They can then ask questions and use ArcGIS to determine the answers. How much water is in the Toshka Lakes? What happens if Lake Nasser rises and more water flows down the canal? Will more lakes form, or will the lakes that are there just get bigger? How much water might be evaporating from the lake surfaces? How much water has to flow down the canal to keep the lakes at a particular level? What might happen as the annual Nile flood fluctuates from year to year?

The document posted for downloading contains two homework assignments, two in-class activities, and a wrap-up assignment.

You can also download a GIS Primer (Acrobat (PDF) 1.2MB Mar30 10) that we have written, which is a simple GIS "how-to" manual for tasks including those used in this exercise.

Determining whether students have met the goals

Students will be evaluated on the basis of the thoroughness and accuracy of their GIS analyses, on the questions they ask and how they answer them using GIS, and on their overall assessments of the Toshka Lakes with respect to the New Valley Project.

More information about assessment tools and techniques.

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