Consider the following statements:

1. In the lower course, vertical corrasion has almost ceased, although lateral erosion may continue.
2. Repeated floods deposit sediment over adjoining lowlands and gradually build flood plains.
3. An abandoned meander loop may become an ox-bow lake and later degenerate into a swamp through silting.
4. Deep coastal water, strong cross-currents and large sediment-trapping lakes within the river course favour delta formation.

Which of the statements given above are correct?