Chapter 10 – Disaster Management (Class 7, Maharashtra Board)

Chapter 10: Disaster Management

Class 7 • Maharashtra Board General Science Mobile-friendly • Clear line spacing • Colourful & neat

1) 20 Important Words & Meanings (Meanings in Hindi)

Disasterऐसी बड़ी घटना जिससे जान-माल का भारी नुकसान हो।

Natural Disasterजो प्रकृति से होता है (जैसे बाढ़, सूखा, भूकंप)।

Manmade Disasterजो मानव की गलती/कर्म से होता है (जैसे आग, दुर्घटना)।

Famineलंबे समय तक अनाज व पानी की भारी कमी।

Droughtबारिश न होने से पानी की कमी।

Floodअत्यधिक पानी से क्षेत्र का डूब जाना।

Cloudburstबहुत कम क्षेत्र में बहुत तेज़ बारिश (≈ $\\ge 100$ mm/घंटा)।

Lightningबादलों में विद्युत का चमकना/धरती पर गिरना।

Volcanoधरती के भीतर से लावा/राख/गैस का फटना।

Tsunamiसमुद्र में भूकंप/ज्वालामुखी से बनी विशाल लहरें।

Storm/Cycloneतेज़ हवाओं के साथ वर्षा/तूफ़ान।

Landslideपहाड़ की मिट्टी/चट्टानों का अचानक खिसकना।

Early Warningखतरे से पहले सूचना देना।

Mitigationनुकसान कम करने की तैयारी।

Preparednessआपदा आने से पहले की योजना/प्रशिक्षण।

Evacuationखतरनाक जगह से सुरक्षित स्थान पर जाना।

Reliefबचाव के बाद तात्कालिक सहायता (खाना, पानी, दवा)।

Rehabilitationलंबे समय तक पुनर्वास व पुनर्निर्माण।

First Aidघायल/बीमार को तुरंत दी जाने वाली प्राथमिक मदद।

Lightning Conductorबिजली गिरने से भवन की रक्षा करने वाली तांबे की पट्टी/प्रणाली।

2) Important Notes (Quick Revision)

Disasters are of two main types: Natural (flood, drought, lightning, cloudburst, volcano, tsunami, storms) and Manmade (fires, accidents, pollution).
Famine: long-term severe scarcity of food & water. Major natural cause: drought; other factors: floods, crop pests/diseases, environmental changes; manmade: war, unrest, poor transport, misuse of water.
Reduce famine impact: planned water use & reuse, local water harvesting, percolation tanks, tree plantation, stop deforestation, weather-based crop planning.
Cloudburst: sudden, very heavy rain over a small area (≈ $\\ge 100\\ \\text{mm/hr}$) due to rapid condensation; can cause flash floods & landslides.
Flood protection: small dams in hills, percolation tanks, riverbed management, afforestation, interlinking/local diversions where appropriate, early warnings, evacuation.
Lightning safety: avoid open grounds/high places/trees; stay away from poles, fences, water; switch off mains, unplug devices; keep ~15 ft (~4.5 m) spacing between people; crouch low on dry insulating material; safest in a pucca house with a lightning conductor.
Volcano: ejects lava, ash, hot gases; forms new landforms; pollutes air; raises local temperature; may trigger rain; buries forests/settlements. Eruptions cannot be stopped, but can be predicted and managed.
Tsunami: sea-floor earthquake/volcano displaces water → fast waves ($\\approx 800\\text{–}900\\ \\mathrm{km\\,h^{-1}}$) that grow tall near coasts (up to ~30 m). Needs rapid warning & evacuation.
Storm safety: trim risky branches, shelter in safe structures, shut gas valves & electricity, inform family, assist others with temporary shelter.
Institutions: NDMA (national), State/District Disaster Management Authorities, SDRF/NDRF, and global support (UNDP) coordinate preparedness, response, and recovery.

Hazard	Key Cause/Trigger	Immediate Effects	Mitigation & Safety
Famine	Drought, crop failure	Food & water scarcity	Water harvesting, crop planning, storage, equitable distribution
Cloudburst	Rapid condensation in small area	Flash flood, landslide	Avoid valleys/foothills, early warning, slope stabilization
Lightning	Charge separation in clouds	Strikes, fires, injury	Lightning conductor, indoors safety, crouch posture
Tsunami	Sea-floor quakes/volcano	Inundation, strong currents	Coastal sirens, vertical evacuation routes, drills
Storms	Low pressure & winds	Wind damage, surge	Prune trees, secure roofs, safe shelter, updates

3) 20 Important “One-Word Answer” Type Questions

A long-term severe scarcity of food and water is called?
Famine.
Main natural cause of famine?
Drought.
Sudden heavy rain ≥ $100$ mm/hour over a small area is called?
Cloudburst.
Device that protects buildings from lightning?
Lightning conductor.
Sea waves generated by sea-floor earthquakes?
Tsunami.
Type of disaster: flood—natural or manmade?
Natural.
Type of disaster: railway accident?
Manmade.
Very hot molten rock thrown by volcano?
Lava.
Indian national body for disaster policies?
NDMA (National Disaster Management Authority).
First help given to the injured is called?
First aid.
Moving people to a safer place is called?
Evacuation.
Planting trees to reduce floods/erosion is?
Afforestation.
A slow-onset disaster due to lack of rain?
Drought.
Waves travel speed in deep ocean during tsunami (approx.)?
$800\\text{–}900\\ \\mathrm{km\\,h^{-1}}$.
Best shelter during lightning?
A pucca house/building.
Which practice: saving water for later use?
Water harvesting/conservation.
Which organisation sends international aid & experts?
UNDP (United Nations Development Programme).
Immediate post-disaster help: food/water/medicine—called?
Relief.
Long-term rebuilding of houses & livelihoods—called?
Rehabilitation.
A sudden rotating windstorm over sea is?
Cyclone/Storm.

4) 20 Very Short Answer Questions (1–2 lines)

Why does drought increase famine risk?
No rain → crop failure → scarcity of food & water → famine conditions.
State two manmade causes that can worsen famine.
War/unrest and poor transport/distribution of food.
How does deforestation increase disaster risk?
Less roots → more erosion & runoff → floods/landslides intensify.
Define cloudburst in one line.
Extremely heavy rain ($\\ge 100$ mm/hour) restricted to a small area.
Why avoid foothills during heavy rain?
Flash floods/landslides/debris flows can rush down slopes suddenly.
One flood mitigation measure in hilly regions?
Small dams/check dams and terracing.
Give two lightning precautions outdoors.
Avoid open fields & tall objects; keep away from water/metal fences.
Safe body posture in lightning if no shelter?
Crouch low, feet together, hands on knees on a dry insulating surface.
Name two materials ejected by volcanoes.
Lava and ash (also hot gases, mud).
What triggers a tsunami?
Sea-floor earthquakes/volcanic eruptions displacing large volumes of water.
Why do tsunami waves grow near coasts?
Shallow water slows waves but increases their height (shoaling).
One coastal safety action for tsunamis.
Immediate evacuation to higher ground/vertical shelters after warning.
Why trim risky tree branches before storms?
To prevent falling limbs from causing damage/injury.
Household action during a storm alert?
Turn off electricity & gas; stay indoors away from windows.
Why keep emergency numbers handy?
To contact help quickly (fire/medical/police/disaster helplines).
One benefit of percolation tanks.
Recharge groundwater and reduce flood peaks.
What is “preparedness”?
Planning, training and drills done before a disaster.
What is “mitigation”?
Measures that reduce the impact (e.g., embankments, codes, plantations).
Which place is safest during lightning—open field or pucca house?
Pucca house (especially with lightning protection).
Name an Indian flood-control planning effort from 1976.
National Flood Commission (1976).

5) 20 Short Answer Questions (2–3 lines)

How is famine linked with both natural and manmade factors?
Natural: drought/floods/pests; manmade: war, poor storage/transport, misuse of water—together they reduce availability & access.
Suggest three ways a village can reduce famine risk.
Local water harvesting, crop diversification based on forecasts, community grain banks.
Explain the process leading to a cloudburst.
Rain vaporizes near hot ground, returns to clouds; vapour overload → rapid condensation → sudden intense rain over a small area.
List flood-protection measures mentioned in this chapter.
Small dams, percolation tanks, riverbed leveling/management, afforestation, linking rivers (where feasible).
Why maintain ~15 ft (~4.5 m) spacing during lightning?
To reduce risk of multiple casualties from ground current/side flashes.
How does a lightning conductor protect a building?
It provides a low-resistance path for charge to reach earth safely via copper strip and earthing plate (coal & salt enhance earthing).
State effects of a volcanic eruption.
New landforms from lava; ash/gases pollute air; temperature rise; heavy ashfall; forests/settlements buried; possible rains.
Why can’t we prevent a volcano but still manage risk?
Eruptions are natural/geologic; science enables monitoring, early warning, evacuation and zoning to reduce loss.
Why are tsunami waves small in deep ocean but huge at shores?
High speed in deep water with long wavelength; in shallow areas speed drops and height rises (energy conservation).
Name immediate actions after a tsunami warning.
Move inland/uphill quickly, avoid beaches/rivers, follow sirens/SMS, carry emergency kit.
How do afforestation and soil conservation reduce disasters?
Roots hold soil, reduce runoff, increase infiltration → fewer floods/landslides and better groundwater.
Why is sharing storm information important?
Timely warnings save lives and property—secrecy delays evacuation and increases risk.
What household items are essential in an emergency kit?
Water, dry food, torch, batteries, first aid, necessary medicines, power bank, copies of documents.
Why avoid using plugged-in devices during thunderstorms?
Surges/strikes can travel via wires causing shocks and damage.
Role of NDMA/SDMA in disasters.
Policy, planning, early warning, coordination with district authorities, capacity building & response.
How do percolation tanks help both drought and flood?
They store excess rain, reduce peak flows, and recharge aquifers for dry seasons.
Give two safe behaviours during storms.
Shelter indoors away from windows; switch off gas & electricity; inform relatives of your location.
Why is misuse/unlimited lifting of water risky?
Depletes sources, reduces resilience to drought and increases famine risk.
How do locusts/pests relate to famine?
They destroy crops → food scarcity → famine severity increases.
What is the purpose of disaster drills in schools/communities?
To practice evacuation & first aid so that response is quick and orderly during real events.

6) Textbook Exercise – Perfect Answers

Q1) Find the odd man out.

(a) Famine, earthquake, cloudburst, railway accident — odd: railway accident (manmade; others natural).
(b) Drought, heavy rains, storm, tsunami — odd: drought (slow-onset/“no water” vs others are sudden “excess water” events).
(c) Lava, hot mud, ash, locusts — odd: locusts (biological pest, not a volcanic product).
(d) Washing away of crops, attack of pests on crops, volcano, singeing of crops — odd: volcano (a cause/hazard; others are crop damages/effects).

Q2) Remedial measures for the following calamities.

(a) Famine: water harvesting & reuse; drought-resistant crops; crop rotation; community grain banks; afforestation; proper storage & distribution; avoid water misuse.

(b) Lightning strike: install lightning conductors; avoid open grounds/trees/metal fences/water; unplug devices; maintain spacing; crouch low on dry insulating material; safest indoors.

(c) Storm: prune weak branches; secure roofs/loose items; stay indoors away from windows; shut gas & electricity; keep emergency kit; follow official advisories.

(d) Cloudburst: avoid foothills/valleys, stay on higher safe ground; early warnings; slope stabilization, check dams; do not cross flooded streams; community evacuation plan.

Q3) True or false? Give reasons.

(a) “Information about a forthcoming storm is to be kept secret.” — False. Timely public warning saves lives and property.
(b) “You should not swim when there is lightning in the sky.” — True. Water conducts electricity; risk of strike is high.
(c) “It is possible to prevent the eruption of a volcano.” — False. Eruptions cannot be prevented; only predicted/managed.
(d) “Heavy rains result in famine.” — False. Heavy rain usually causes floods; famine is mainly due to prolonged scarcity (often drought), though excessive rain can damage crops locally.

Q4) Write answers in your own words.

(a) What is a tsunami? What gives rise to it? Tsunami is a series of large sea waves generated by sea-floor earthquakes/volcanoes/landslides that displace huge water volumes. Waves travel fast offshore and grow tall near coasts.

(b) What is a cloudburst? Extremely heavy rainfall ($\\approx \\ge 100\\,\\mathrm{mm\\,hr^{-1}}$) over a very small area in a short time due to rapid condensation in moisture-laden clouds.

(c) Effects of a volcano. Ejection of lava/ash/gases; formation of hills/islands; air pollution & temperature rise; forests/settlements buried; rains/flash floods triggered by ash.

(d) Measures to prevent loss of life due to lightning. Use lightning conductors; take shelter in pucca structures; avoid open grounds/trees/water/metal; unplug devices; maintain spacing; crouch posture if exposed.

Q5) Measures taken in Maharashtra to deal with floods & landslides (disaster management programme).

Early warning & monitoring (rainfall, dam releases), embankments & river training, percolation tanks/check dams, afforestation & slope stabilization, evacuation routes & shelters, mock drills by SDMA/DDMA, community awareness, and coordination with NDRF/SDRF for response & rescue.

Q6) With reference to disaster management—what will you check at home?

First-aid kit, personal medicines, emergency numbers (fire/medical/police/helplines).
Torch, batteries, power bank, whistle; 3-day stock of water & dry food.
Gas regulator off position; knowledge of main electric switch.
Important documents in waterproof pouch; emergency cash.
Safe storage of matches/chemicals; basic fire extinguisher/sand bucket.
Family emergency plan, meeting point, and evacuation routes.
For monsoon: roof leakage check, tree pruning nearby, drainage clear.

✅ Disaster readiness starts at home — stay informed, stay prepared, stay safe.

10. Disaster Management