Summary:

• The Sahara desert represents the driest region on earth which covers ancient river courses.
• The Sahara was once green and experienced wet climate in the past (rivers and lakes), which recharge the regional ground water aquifers such as northern Darfur mega lake; these can be revealed by using the radar space data.
• 500 wells have been drilled for drinking and irrigation, the proven water resources are estimated to be capable of supporting agriculture over 150,000 acres for at least 100 years.
• At its maximum extent the mega lake occupied an area of about 30,750 km2 and has contained 2,530 km3 of water.
• The many bright patches most probably assignable to lacustrain carbonate deposits are clearly visible and implying the earlier formation of lakes and playas along the wades bed.
• Integrated remote sensing and GIS techniques are beneficial for mapping former rivers courses and delineating their drainage basins of the great Sahara.
• These courses must have hosted a great deal of surface water in the past where part of it would have speed down and replenished the ground water aquifer.