A GIS EXERCISE FOR STUDENTS TO EVALUATE A PROPOSED SOLAR-HYDROELECTRIC POWER PROJECT IN THE QATTARA DEPRESSION, EGYPT

The Qattara Depression in the hyperarid Sahara of northern Egypt is an elongate depression covering about 18,000 km² and extending to more than 130 m below sea level. The basin is uninhabited, and the floor contains large tracts of salt pan and salt quicksand with a thin salt crust. The Depression lies only about 70 km from the Mediterranean at its closest point. Beginning as early as the second decade of the 20^th century, proposals have arisen several times for generating electric power by piping water from the Mediterranean to the edge of the Depression and allowing it to fall through a hydroelectric power station at the level of the Depression floor. Influx could be balanced by evaporation of the effluent lake in this hyperarid setting (the "solar" part), allowing for long-term operation of the plant accompanied by the slow accumulation of salt.

I have developed a GIS project geared toward students at the introductory level that involves students in reassessing the viability of the Qattara Basin Project using modern GIS technology and DEMs acquired by the Shuttle Radar Topography Mission (SRTM). Students use ArcMAP to test various combinations of canal/tunnel location, power plant location, lake level, and lake surface area to see which lake level and power plant location maximizes installed capacity (e.g., higher lake levels have more surface area, evaporate more water, and allow more annual influx, but the drop is smaller). Students begin by calculating maximum installed capacity for a simple canal-tunnel system. They then use ArcMap to investigate whether pumped storage could augment the system and, if so, what the parameters of that system would have to be and where it would be ideally located.

Students prepare for this project earlier in the semester by learning how to use ArcMap to determine areas, volumes, and evaporation amounts from lakes that have formed in the Toshka Depression in southern Egypt by overflow from Lake Nasser. Students use SRTM data and Shuttle orbital images to quantify the growth of the lakes in the early 21^st century and use the volume and evaporation calculations to evaluate whether the Toshka Lakes should or shouldn't be an active component of Egypt's New Valley Project. Data for the project and course materials are available from the author.