NCERT Solutions for Class 9th Social Science Chapter 2 Completing the disaster exercises on pages 33–36 — LET'S EXPLORE

Book page 32 Updated on2026-09-08

Q1.
Complete the exercises given at the end of each type of disaster with the help of newspapers, atlases, and books. Make a list of disaster-prone areas from India and the world and enlist mitigation measures quoting recent examples.
Answer

Method: for each of the four disasters the chapter describes, fill the three blanks it prints — Prone areas, Mitigation measures, Recent examples. Take the prone areas from your atlas (they follow the landform, so look for the right kind of terrain), take the mitigation measures from the causes listed in the chapter itself — every cause suggests its own remedy — and take the recent examples from newspapers of the last year or two, writing down the date and place each time.

The completed exercises:

1. Landslides (page 33)

Prone areasIndia — the Himalayan states (Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim), the north-eastern hills, the Western Ghats (Kerala, Karnataka, Maharashtra) and the Nilgiris. World — the Andes, the Alps, the Rockies, the mountainous parts of Nepal, China, Japan, Indonesia and Colombia.
Mitigation measuresAfforestation and grass cover so roots bind the slope; terracing and retaining walls; proper drainage so water does not build up inside the slope; controlled blasting and correct slope angles when cutting roads; banning construction on steep slopes and along drainage paths; hazard-zone mapping; rain-gauge based early warning; and educating residents to recognise warning signs — cracks in the ground or in walls, tilting trees and poles, and suddenly muddy stream water.
Recent examplesLandslides in the Himalayan and Western Ghat districts recur every monsoon. Write down two from this year's newspapers with the district and date.

2. Avalanches (page 34)

Prone areasIndia — the high Himalaya of Jammu and Kashmir, Ladakh, Himachal Pradesh, Uttarakhand and Sikkim, especially high passes and army posts. World — the Alps (Switzerland, France, Austria, Italy), the Rockies, the Andes, and the mountains of Japan and Norway.
Mitigation measuresSnow and weather monitoring with avalanche bulletins; avalanche barriers, snow fences and deflecting walls above roads and settlements; planting and protecting slope forests; controlled release of unstable snow before it builds up; closing high roads and passes after heavy snowfall or a sudden warm spell; and training for trekkers, skiers and soldiers, including the use of beacons and probes.
Recent examplesAvalanches on high Himalayan passes and near border posts are reported most winters. Add one recent case with its date and location.

3. GLOFs (page 35)

Prone areasIndia — the glacier-fed valleys of Uttarakhand, Himachal Pradesh, Sikkim, Arunachal Pradesh and Ladakh. World — Nepal, Bhutan, Tibet, Pakistan, the Peruvian Andes, Iceland and Alaska.
Mitigation measuresSatellite monitoring of glacial lakes so a growing lake is spotted early; lowering dangerous lakes by siphoning or by cutting a controlled outlet channel; strengthening the moraine dam; automatic water-level sensors linked to sirens downstream; keeping settlements, roads and hydel projects out of the flood path; and evacuation drills in downstream villages.
Recent examplesThe Chamoli disaster of February 2021 in Uttarakhand, described in the THINK ABOUT IT box on page 29, is the chapter's own case. Add any newer event you find in the newspapers.

4. Dust storms (page 36)

Prone areasIndia — Rajasthan and the Thar, Gujarat, Haryana, Punjab, Delhi and western Uttar Pradesh, mainly in the hot months before the monsoon. World — the Sahara and the Sahel, the Arabian Peninsula, Iran, Central Asia, western China, the interior of Australia and the dry plains of the United States.
Mitigation measuresShelter belts and windbreaks of trees along field edges; keeping a stubble or crop cover on the soil instead of leaving it bare; stabilising dunes with grasses and shrubs; controlling overgrazing; contour ploughing across the wind direction; sand fences; weather warnings so schools, road and air traffic can be halted; and masks and eye protection for people who must be outdoors.
Recent examplesPre-monsoon dust storms over north-western India are reported almost every summer. Note one, with the date and the states affected.
The pattern worth noticing: every mitigation measure in these four boxes belongs to one of three families — hold the material in place (trees, bunds, walls, fences), take the water away safely (drains, controlled outlets, siphons), or keep people out of the path (zoning, early warning, evacuation). If you know the cause, you can work out the measure for yourself; you do not have to memorise the list.
Tip: for the "recent examples" line, always write place + district + month + year and the source newspaper. A dated example is evidence; an undated one is only a claim.
Was this helpful? Report an error