largest alluvial plain

The  indo Gangetic brahmaputra Plain is the largest alluvial plain in the world.It extends for a length of 3200 km from the mouth of the Indus to the mouth of the Ganga,and lies partly in Pakistan ,and partly in India .The Indian sector is about 2400 km long,with an average width that varies from 150 to 300 km,and an area that covers 7.8 lakh sq.km
     The region include basins of the great river ,Ganga,Indus,and Brahmaputra together with their tributaries, and is one of the most densely populated areas on Earth .This vast plain is extremely fertile and productive,because of the alluvial soil brought down by the rivers during their journey down from the mountains.
      The plain is also the cradle of many civilizations, for its rivers served as arteries of commerce and  communication in ancient time