JKBOSE 9th Class Social Science Solutions Chapter 1 Natural Disasters

● Types of disasters—Natural and Man made.

● Mitigation—Efforts to reduce loss of life and property.

● Bhopal Gas Tragedy—in 1984.

● Earthquake Zones—I, II, III, IV, V.

● Richter Scale—Scale to measure magnitude d earthquake.

● Flash Flood—A rapid and extreme flow of water.

● Ring Bunds—Ring like structures.

● Cloud Burst—A disasterous weather event.

● Effects of cloud Burst—Flash floods, Mudslides.

● De salination—Removal of some amount of salt from saline water

1. Natural disasters : An event caused by natural hazards.

2. Man-Made disasters : Events causing damages due to man-made activities.

3. Earthquake : A sudden shaking of earth’s surface.

4. Seismograph : An instrument used to measure the magnitude of earthquake.

5. Epicentre : The point on the earth surface and is directly above the focus.

6. Focus : The point inside the earth where an earthquake originates.

7. Retrofitting : The process of strengthening the older buildings.

8. Landslide : It is the movement of a mass of soil down the slope.

9. Famine : A wide spread scarcity of food.

10. Cloud burst : When rainfalls at the rate of 100 mm per hour.

1. Disasters that are caused by nature are called as ……… .

2. The earthquake zoning map divides India into ……… Seismic Zone.

3. The state of Jammu Kashmir falls in Seismic Zone …….. and ………. .

4. …………….. is a large mass of snow that moves rapidly down in a mountain slops.

5. ………. can be defined as a lack or shortage of water for an unusually long period.

6. A ………. is a wide spread scarcity of food in an area.

7. Storing rain water on the roofs of the houses is called ……… .

8. ……… is a disasterous weather event in which the heavy rainfall occurs on a localised area.

9. An ………. is a natural disaster in which the sudden shaking of the earth’s surface is involved.

10. Instrument used to measure the magnitude of an earthquake is called as ……….. .

Ans.— 1. Natural disaster 2. Four 3. IV and V 4. Avalanche 5. Drought 6. Famine 7. Roof top rain water harvesting 8. Cloud burst 9. earthquake 10. seismograph.

Ans.— An earthquake 6.76 on Richter scale.

Ans.— Landslide.

Ans.— Landslides.

Ans.— Cloud Burst.

Ans.— Avalanche.

Ans.— A hazard causes damage to life, health, property or environment. A hazard becomes a disaster when wide spread loss of life etc. occurs.

Ans.— A natural disaster is an event that is caused by natural elements and leads to loss of life and environment.

(i) 2004 Indian ocean Tsunami

(ii) 2005 Muzaffarabad earthquake

(iii) 2005 waltengo snow avalanche

(iv) 2010 Cloud burst in Leh.

Area	Year	Magnitude
(i) Assam	1897	8.7
(ii) Kangra	1905	8.0
(iii) Kutch	2001	7.7
(iv) Indian Ocean (Tsunami)	2004	9.3

Ans.— Drought is defined as lack or shortage of water for a long period. A famine is wide spread scarcity of food caused due to crop failure.

Ans.— An earthquake is a sudden shaking of earth’s surface due to release of energy in the Earth’s crust. This energy is released when two parts of the rock masses move suddenly in relation to each other along a fault. Earthquake is the most destructive natural hazard and its occurrence is usually sudden with little or no warning.

Ans.— Earthquake does not directly kill people but buildings do. The structures /buildings/houses should be designed and built in a way that these can withstand ground shaking. Architectural and engineering inputs need to be put together to improve building design and construction practice. Soil types must be analyzed before construction and structures must not be built on soft soils without proper designing. Buildings built on s Isoft soils are more likely to get damaged even if the earthquake is not particularly strong in magnitude. Buildings/houses should not be constructed very close to each other in earthquake prone areas. This can cause much damage due to collisions during the occurrence of earthquake.

Ans.— Natural disasters of earthquake, landslides, avalanche are likely to occur in hilly areas.

Earthquake of Muzaffarabad. On 8th October, 2005 at 9.20 a.m., an earthquake with magnitude of 7.6 on Richter scale and epicenter near Muzafarabad, struck the northwestern part of the Himalaya causing heavy damage to buildings and infrastructure and loss to life. It was one of the deadliest earthquakes in the history of Indian subcontinent in terms of loss of life and property. The earthquake devastated about 40,000 km² in both parts of Jammu and Kashmir and Northern Pakistan and killed more than 80,000 people and injured about one lac. The earthquake affected more than 500,000 families. About 3.5 million people got dislodged including about 1.6 million children. Besides, more than 3100 schools got damaged, 20000 children got killed and another 20000 injured in Pakistan and its administered part of Kashmir. In addition, approximately 250,000 farm animals died due to collapse of stone barns.

It is estimated that more than 780,000 buildings were either destroyed or damaged beyond repair, and many more were rendered unusable for extended periods of time. Property loss is placed at 4 billion US dollars. Three lac people got unemployed in the aftermath. In the State of Jammu and Kashmir, the Karnah and Uri Tehsils and Poonch District were badly hit. Buildings collapsed, roads got damaged, power and communication got destroyed, heavy landslides and rockfalls took place, besides heavy toll to the life (both people and cattle).

Ans.— Drought can be defined as a lack or shortage of water for an unusually long period. A drought is an extended period of months or years when a region notes a deficiency in its water supply whether surface or underground. A situation of drought occurs generally when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region. Drought, if takes place can occur for years together but even a short, intense drought can cause significant damage and disturb the local economy.

Ans.— Landslides are mostly observed to affect hilly areas and are recurring phenomenon occurring in all parts of India, from Kerala to Himalayas. Areas prone to landslides include the Eastern and Western Ghats, the Nilgiris, the Vindhyans, mountains of northern and north-eastern states throughout the Himalayan range. The incidence of landslides mostly occurs during and after spells of heavy rains. The major consequences of landslides include :

Landslids occur mostly when water infiltrates into the land during heavy rains. In order to prevent or minimize this infiltration, natural drains should be strengthened to allow the smooth flow of water which otherwise gets stranded and infiltrated.

Retaining walls : Construction of concrete retaining walls prevents the slippage from slopes.

Ans.— Mitigation (safety) measures during an earthquake :

(i) Remain calm, try to be calm and reassure others to derive an action plan.

(ii) If you are inside a building, watch for falling plaster/bricks/stones, light fixtures and other objects.

(iii) Watch for high book cases, shelves and other cabinets which might slide or topple.

(iv) Stay away from glass, windows, mirrors and chimneys.

(v) If in danger get under a table, desk or bed in a corner away from the window with your head covered by your arms.

(i) Leh

(ii) Srinagar

(iii) Muzaffarabad

(iv) Jammu

Ans.— (iii) Muzaffarabad.

(i) 2001

(ii) 2004

(iii) 2007

(iv) 210.

Ans.— (ii) 2004.

(i) Delhi

(ii) Jammu

(iii) Bhopal

(iv) Amritsar.

Ans.— (iii) Bhopal.

(i) I

(ii) II

(iii) III

(iv) IV.

Ans.— (iv) IV.

(i) Earthquake.

(ii) Waves

(iii) Volcanoes

(iv) Tides.

Ans.— (i) Earthquake.

(i) Natural disaster

(ii) Mitigation

(iii) Man Made Disaster

(iv) None of the above.

Ans.— (i) Natural disaster.

Ans.— Man made disasters.

Ans.— It can destroy the economic and social life of people.

Ans.— Tsunami.

Ans.— Gas Tragedy.

Ans.— Earthquakes, landslides, floods, cloud burst.

Ans.— Five.

Ans.— Strengthening older buildings.

Ans.— Growing more plants along the landslide zone.

Ans.— HAZARD is a situation that poses a level of threat to life, health, property or environment. A hazard becomes a disaster when it hits an area affecting the normal life.

Ans.— Disasters occur when hazards meet vulnerable situations. A disaster is a natural, man-made  event.

Disasters can destroy the economic, social and cultural life of the people.

Ans.— Mitigation is an effort to reduce loss of life and property by reducing the impact of disasters. Mitigation is taking preventive actions before the next disaster happens in order to reduce human and financial consequences.

Ans.— The state of Jammu and Kashmir is prone to various natural disasters like earthquakes, landslides, floods, snow avalanches, cloud bursts etc. These disasters are perceived to be on increase in terms of their magnitude, frequency and economic impact.

Ans.— Earthquakes result into collapse of buildings, damage to infrastructure and environment and loss of life. Electric short circuit and gas leaks can create big fires and broken water pipes, damaged water tanks/dams can lead to severe flooding leading to misery of the affected community.

Ans.— Earthquake magnitude or amount of energy released is determined by use of a seismograph, an instrument that continuously records ground vibrations. A scale developed by a seismologist named Charles Richter in the year 1935, to record the magnitude of earthquakes is called as Richter scale.

Ans.— Disasters are as old as human history. The risk of disasters has increased dramatically in the recent past. These disasters cause huge damages to the life, property and livelihood. The state of Jammu and Kashmir is prone to various natural and anthropogenic (man-made) disasters. The 7.6 magnitude earthquake that struck on 8th October, 2005 killed about 1400 people in this part of Jammu and Kashmir, damaged thousands of buildings, roads and caused huge landslides. Similarly about 79,000 people died, more than 1,00,000 got injured and extensive damage was done to the houses, property and other physical infrastructural facilities in Pakistan and Pakistan administered Jammu and Kashmir. Thousands of people have died in our state due to snow avalanches, landslides, cloud bursts, terrorist activities and other disasters.

Some important earthquakes in Jammu and Kashmir

Area	Year	Magnitude
Udhampur,	1951	6.0
Udhampur,	1962	6.0
Kathua,	1947	6.0
Kathua,	1950	6.0
Kathua,	1951	6.0
Uri Muzaffarbad	2005	7.6

Ans.— Snow Avalaneches : About 200 persons were killed in January 1995 after avalanches buried the highway connecting Srinagar and Jammu. Five buses plunged off the highway into valley below near Jawahar Tunnel. February 19-20, 2005: Around Waltengoo, Kashmir about 250 people got killed in avalanches after heavy snowfall in Kashmir. On February 8, 2008, 29 people were killed, 500 were rescued in snow avalanches from various parts of Kashmir Valley.

Avalanche means down slope movement of snow. It is a large mass of snow that moves rapidly down a mountain slope sweeping and grinding everything in its path. Avalanches can occur anywhere with steep slopes and unstable snow. These are generated by an external disturbance such as a person or animal passing over a slope, due to warming, or due to structural failure of snow heap lying on mountain slopes.