Morphometric analysis of Toshka Lakes in Egypt: A succinct review of geographic information systems & remote sensing based techniques
Radwan G. Abd Ellah
Abstract
Currently, freshwater resources occupy a top place among other natural resources on the planet. The Egyptian water resource system is complex and uncertain; therefore, the major challenge is to close the rapidly increasing gap between the limited water resources and escalating demand for freshwater. The Toshka Depression is in a hyper arid area in the Western Egyptian Desert. This depression is considered the first line of defense to accommodate any sudden floods. Its water is lost mainly through evaporation without being utilized optimally. Remote sensing (RS) and geographic information systems (GIS) were integrated to assess the surface hydrological changes of Toshka Lakes. The massive floods of the Nile River resulted in the gradual formation of four new inland lakes in the Toshka Depression (first lake of 12.5 km3, second of 0.4 km3, third of 5.2 km3, and fourth of 22.1 km3). Those lakes were diminishing with low Nile discharges and appeared again with the Lake Nasser high flood. Therefore, measures must be taken to obtain the most benefits from the lakes as freshwater and avoid the negative effects as they eventually turn into saline basins owing to evaporation.