With reference to the Barrier Lake, recently seen in the news in the context of floods along the Nepal–China border, consider the following statements: 1. A barrier lake can form when a landslide, rockfall, avalanche or other debris blocks the course of a river, temporarily impounding water upstream. 2. The sudden failure or breaching of such a natural barrier can trigger a Landslide Dam Outburst Flood (LDOF), releasing water and debris rapidly downstream. Which of the statements given above is/are correct? |ForumIAS

Q. With reference to the Barrier Lake, recently seen in the news in the context of floods along the Nepal–China border, consider the following statements:
1.A barrier lake can form when a landslide, rockfall, avalanche or other debris blocks the course of a river, temporarily impounding water upstream.
2.The sudden failure or breaching of such a natural barrier can trigger a Landslide Dam Outburst Flood (LDOF), releasing water and debris rapidly downstream.
Which of the statements given above is/are correct?

[A] 1 only

[B] 2 only

[C] Both 1 and 2

[D] Neither 1 nor 2

Answer: C

Notes:

Explanation: Both 1 and 2

Statement 1 is correct: A barrier lake is formed when a natural obstruction—such as a landslide or ice-rock avalanche—blocks a river channel and causes water to accumulate upstream. The recent Nepal–China border incident involved a landslide-formed lake.

Statement 2 is correct: If the natural barrier breaches or overflows, the impounded water can be released suddenly, producing a potentially destructive Landslide Dam Outburst Flood (LDOF) carrying large quantities of water, sediment and debris downstream.

Source: IE

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