Water is flowing in a horizontal, frictionless, rectangular channel. A smooth hump is built on the channel floor at a section and its height is gradually increased to reach choked condition in the channel. The depth of water at this section is $y_{2}$ and that at its upstream section is $y_{1}.$ The correct statements(s) for the choked and unchoked conditions in the channel is/are

1. In choked condition, $y_{1}$ decreases if the flow is supercritical and increases if the flow is subcritical.
2. In choked condition, $y_{2}$ is equal to the critical depth if the flow is supercritical or subcritical.
3. In unchoked condition, $y_{1}$ remains unaffected when the flow is supercritical or subcritical.
4. In choked condition, $y_{1}$ increases if the flow is supercritical and decreases if the flow is subcritical.