Consider the following statements:

1.River Luni, which flows in the west of Aravali, is the largest river system of Rajasthan.

2.The lakes and playas in the desert have brackish water which is an important source of obtaining salt.

3.River Saraswati and River Sabarmati join each other at Govindgarh, from where the river arises as Luni.

4.River Luni is an ephemeral river.

Which of the statements given above is/are correct?