In the 1950s, Egyptian President Gamal Abdel Nasser set out to alleviate the cyclic flooding and drought periods in the Nile River region, build the agricultural economy and food supplies, and provide hydroelectric power to towns. Nasser’s government then designed a large dam to tame the mighty Nile River. The Aswan High Dam took a decade to build. The rockfill dam used around 44 million cubic meters (57 million cubic yards) of Earth and rock for its construction—a mass sixteen times greater than Great Pyramid of Giza. It offered better control of the flood cycles and more water storage than its predecessor, the Aswan Low Dam, to the north.
The new 111-meter (360-foot) tall dam created one of the largest man-made lakes in the world. Named for the Egyptian President, Lake Nasser stretches 480 kilometers (300 miles) long and 16 kilometers (10 miles) wide. Storing more than 100 cubic kilometers (24 cubic miles) of water, the lake took approximately six years to fill.
The Operational Land Imager (OLI) on Landsat 8 acquired the data for this natural-color image of Lake Nasser (the Sudanese call their portion Lake Nubia). This composite scene was compiled from cloud-free images from 2013 to 2020. Located in a hot, dry climate with sporadic rain events, the lake loses a lot of water through evaporation and consequently shrinks seasonally in surface area. Water levels are typically highest in November during the flood season and lowest in July during the dry season.
Lake Nasser plays an important role in Egypt’s economy. Approximately one quarter of the nation’s population works in agriculture, which depends heavily on irrigation. With a reliable source of water from Lake Nasser, farmers have been able to plant more crops and to do so multiple times per year with the aid of fertilizers. After the reservoir was filled, the country was able to increase its arable land by 30 percent in the first few years, particularly to the west of the lake. Lake Nasser has also created a fishing industry and is a popular tourist attraction due to its crocodiles.
Researchers, however, are worried about the lake’s future. The Grand Ethiopian Renaissance Dam, which will be Africa’s largest dam for hydroelectric power, is expected to greatly reduce water levels in Lake Nasser and the amount of power generated at Aswan High Dam. Research shows the project, which was 70 percent complete in October 2019, could lead to an irrigation deficit for Egypt in dry years and a decline in fisheries. One study found the lake shrunk 14 percent in surface area from 2015 to 2016, which may have been due to the new dam and the partial filling of its reservoir.
NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey. Story by Kasha Patel.
