Solutions-Class 8-Science-Chapter-9-Disaster Management-Maharashtra Board

There are many changes occur in the surrounding hilly ground before the actual landslide.

• The hard rocks develop cracks and crevices. These are natural changes but due to man-made activities, the cracks are widened due to erosion.
• Due to continuous rain in a region, cracks widen further these cracks make the big rocks to break into smaller stones.
• The plants and small tress of that region are uprooted from the soil,

Due to these factors, soil and rocks run off on a slopy region. This process is speeded up due to rainwater. This running of soil, rocks along with other debris is nothing but landslide, Hence, there is a strong relation between continuous rains and landslide.

Do's' and don'ts' during earthquake are:

The earthquake-proof building is such that even if the earthquake is caused, it should not cause damage to the buildings due to these earth movements. There are some codes of conduct while constructing such buildings.

• It is constructed as per IS 456, IS 1893, IS 13920  the code of conduct given for building constructions, criteria for earthquake resistant design structure, ductile detailing of reinforced concrete structures subjected to seismic forces respectively by 'Indian Standard Institute'.

Advanced technology is used for earthquake resistant construction. The foundation of earthquake-proof building is separated from lower land. The walls are of less weight or they are wooden. The house constructed with special light materials are preferred in earthquake-prone regions.

Effects of landslides are:

• Rivers change their course of flow

• Waterfalls are displaced from their original positions,
• New and artificial water reservoirs, are created,

• Transportation is affected as the roads and railway tracks are blocked due to debris.
• There is large scale damage to property and life. In few eases entire village was buried due to landslide and accompanied rainfall.

• The construction of dams creates a huge water reservoir in which a large portion of land is submerged. 
• Thus, these dams cause excess water pressure in the micro-cracks and fissures in the ground near or under the reservoir.
• Due to this excess pressure, the water seeps into the ground and lubricates the rocks.
• This lubrication reduces friction between the tectonic plates, thereby causing the slipping of plates over one another.
• Hence, in this way dams construction can trigger an earthquake.

• In an earthquake, most of the injuries occur because of falling or toppling over of heavy things like roof and walls of house from above.
• Things like bed, table will protect you from heavy things falling from above.
• Also, it becomes very difficult to maintain one’s balance in a quake. The crouched position under these furnitures will reduce the chances of a fall.
• If there is complete structural collapse, it is hoped that these furniture increase the likelihood of a safe pocket from which you can be rescued.

In monsoon, there is chance of heavy rainfall. The excessive rainfall can cause landslides. The soil and rocks from the hillside can be pushed down along with the flow of rainwater. This debris slides to the lower heights from the hills.
 So, it is never advisable to take shelter near hillsides during monsoon as your life will be at risk as well as you may face problems such as heavy traffic etc.

• During an earthquake, the power supplies are cut off and you may get stuck in the elevator for long time.
• Also there may be chances of fire due to short circuit.
• If the intensity of earthquake is very high, there is chance of lift car falling to the bottom causing you severe damage, but this is very rare.
• It is always better to use stairs at the time of such calamities, so that one can safely come out of the building.
• Therefore, it is said that lifts should not be used at the time of earthquakes.

The surface of the earth trembles at the time of earthquake. These tremors cause seismic waves which are responsible for the movements of the earth’s Surface. The ground thus shakes or it goes up-down. These shocks and wave formed in the interior of the earth spread on the surface in all directions. This causes collapse of the building and other structures on the land. To prevent such disasters the foundation of earthquake proof building is separated from lower land.

If a crowd gathers at the place of earthquake, following are the difficulties faced during relief work:

• Interruption to the clearance of debris
• It people flock in crowd, the rescue work will not be possible.
• The personnel from disaster management cells cannot thus act in time.
• Hindrance to the passage of ambulance carrying earthquake victims
• Aggravation of fear and panic in victims 
• Chances of stampede and theft
• Quarrels among's the people for food and other resources

It will be difficult to manage the situation and thus such crowding should never be done.

International government, non-governmental organisations working for disaster management are:

(1) The International Committee of the Red Cross ( ICRC): It gives physical rehabilitation to people injured by explosive weapons or other types of incident.

(2) The International Federation of Red Cross and Red Crescent Societies ( IFRC): It coordinates and gives international help to victims of natural and technological disasters, to refugees and in health emergencies.

(3) International Rescue Committee (IRC): It provides lifesaving care and life-changing help to refugees forced to flee from war or disaster.

Indian organisations and institutes working for disaster management are:

(1) National Disaster Response Force (NDRF): The multi-disciplinary, multi-skilled, high-tech force of the NDMA are capable of dealing with all types of natural and man-made disasters.

(2) National Disaster Management Authority (NDMA): It lay down the policies, plans and guidelines for Disaster Management to ensure timely and effective response to disasters.

(3) National Institute of Disaster Management (NIDM): It has been given the responsibilities for human resource development, capacity building, training, research, documentation and policy advocacy in the field of disaster management.

(4) National Institute of Seismology :Research work related to earthquakes and allied disaster relief work.

(5) Indian Mountaineering Institute: Program to forecast the landslide and its effects.

This an activity based questions. Kindly do it yourself. But make sure to involve the following points in your survey:

• Primary information of the school: It should include information such as name and address of the school and Head Master, total number of school staff and name and phone numbers of school management members.
• School disaster management committee: Get the information of the members involved in disaster management committee.
• Detailed information about school building: Note the number of rooms, classroom, age of the building, types of roofs under this point.
• Information about school ground: It should include information like distance of ground from the main road, types of play grounds.
• Daily routine of the school: It should include information like working time of the school, lunch break time for the school.
• Possible hazards in the school: It should information such as record of past disaster happened in school, current planning for overcoming disasters.
• Disaster management map of the school: It should have information regarding all the buildings of the school, entrances and exit gates, place of probable danger, safer place at the time of disaster.

This is an activity based question. kindly do it yourself.

The boy shown in the picture is in danger. So, he is typing in his I - pad, “I am at Risk”. After receiving this message, someone will help him. It depends upon, to whom he is sending this message. If he sends this message to us, we can immediately try to help him.

We can make possible guesses and give him following support:

• First of tell him to calm down and ask him what type of risk is he facing and his location.
• If he has faced man made calamities like theft, abduction, then call the nearest police station. Give the police his picture, phone number, address and other details so that they can track him down. We should also try to reach the place as soon as possible.
• If he has faced some road accident, then call the ambulance and police to reach there as soon as possible. We should be also there as soon as possible to give him support.
• In case of fire, call the fire brigade, ambulance and police giving them all the information and urge them to reach there as early as possible.