Why is the Nile River not joined by any tributary on its way?

This is a misconception that river Nile does not have any tributory.While flowing through South Sudan,where it is known as Bahr Al Jabal,it receives Bahr Al Ghazal from the left. Further down stream it receives Sobat from the right. read more

The Nile has two major tributaries, the White Nile and Blue Nile. The only major tributary of Blue Nile is the Atbara River. The Bahr al Ghazal and the Sobat River are the two most important tributaries of the White Nile in terms of discharge. Thank you. read more

The River Nile is the longest river on this planet. The Nile River flows into the Mediterranean Sea. The largest supply of the Nile is the Victoria Lake. The Nile includes a length of about 4, 160 miles or 6, 695 kilometers. Nile River’s average discharge is 680, 000 gallons (3.1 mil liters) each second. read more