Which of the following statements contains information about the regime of the Irtysh River?

Analysis:

We need to analyze each statement about the Irtysh River and determine which one describes its regime (e.g., water flow, seasonal variations).

1. Statement 1: "Irtysh is a large river with a length of 4248 km, flowing through China, Kazakhstan, and Russia." This statement describes the river's length and geographical location, not its regime.
2. Statement 2: "Half of the annual flow of the Irtysh occurs in the spring months." This statement directly describes the seasonal distribution of the river's water flow, which is a key aspect of its regime.
3. Statement 3: "The Irtysh collects water from a territory with an area of 1643 thousand sq. km." This statement describes the river's drainage basin area, not its regime.
4. Statement 4: "The floodplain width of the Irtysh exceeds 30 km." This statement describes the physical characteristics of the river valley, not its regime.

Based on this analysis, statement 2 is the only one that describes the regime of the Irtysh River.

Answer: 2