The advantages are-
1) They are very fertile because of the silt present.and fertile alluvium soil.
2) With adequate water supply and favourable climate, it is agriculturally a very productive part of India.
the disadvantages are-
1) In the northern plains flood occurs frequently.
2) Bhangar which is a terrace-like feature made of alluvium is less fertile than Khadar which is a flood plain renewed every year and is more fertile.