Which of the following statements regarding the seasonal streams (chos) of Punjab is/are correct?

1. They originate from the southern slopes of the Shivalik Hills.

2. They maintain a steady flow throughout the year.

3. They are closely spaced, especially in Hoshiarpur district.

4. Their activity contributes to soil erosion and floods in the foothill zones.

Which of the statements given above is/are correct?