Exercise 2.1
A devastating flood struck the Chamoli district in Uttarakhand in February in which many people and livestock lost their lives. There was severe damage to buildings, roads, bridges, and hydel projects, and connectivity to villages was adversely affected. Can you find out the reasons that led to the sudden and unexpected flood?
The book prints no answer for this
NCERT publishes no answers for this textbook, so there is nothing in the book to check this working against. It has also not yet been read through by hand.
What the task asks for
Find out what caused the sudden flood in Chamoli district, Uttarakhand, in February $\displaystyle 2021$, using newspapers or library sources — the chapter describes the damage but does not give the cause.
Worked example (how to reason it out from the chapter, then check)
List the chapter's possible triggers for a sudden mountain flood and test each one against your source:
A GLOF (Glacial Lake Outburst Flood) — rapid melting of glaciers raises the water level of a glacial lake until its natural dam of ice or loose moraine collapses, releasing the stored water all at once into the valley below.
An avalanche — a sudden mass of unstable snow sliding off a steep slope, which the chapter says can itself strike a lake or weaken its dam.
A landslide — heavy rainfall, earthquakes, deforestation, mining or road construction make a slope fail; the chapter says landslides too can strike a glacial lake.
Then explain why the damage was so heavy: a mountain valley is narrow, so the water arrives fast and hits buildings, roads, bridges and hydel projects in its path, and cuts off the villages beyond.
A good answer must contain
The named source you used, and the date of the report.
One clear cause, or an honest statement that reports disagreed.
The link back to the chapter: this is a disaster tied to a glacial landform, and the chapter lists rising temperatures, heavy rain or snowfall, earthquakes, avalanches and landslides as the things that set such floods off.