The Natron Valley is a natural depression of salt flats in the western desert of Egypt, northwest of Cairo (seen above as blue features in the center of the images). Ancient Egyptians extracted Natron salt from the shallow lakes for mummification purposes. This desolate area, considered a sacred region, became a sanctuary for the desert peoples and for cenobitic monastic communities.
Over the years, agricultural areas have begun to move from the fertile soils of the Nile River, which is to the east. While most fields are irrigated by water from the Nile, high water tables have allowed the use of groundwater to support additional vegetable crops.
These Landsat images, acquired in 1984 and again in 2012, show in green the expanding agricultural areas. Forty years of Landsat imagery can show change over time and are useful to decision makers and others interested in the Earth's changing surface.