Question

Answer the following in your own words.
A. Explain the relation between continuous rains and landslide. Give reasons.
B. Prepare a chart showing 'Do's' and 'don'ts' at the time of earthquake.
C. What are the specifications of an earthquake proof building ?
D. Explain the effects of landslide.
E. Is there any relations between dam and earthquake? Explain.

Answer 1

A. Due to continuous rain in a region,

• the plants and small tress of that region are uprooted from the soil.
• the water enters the cracks and fissures present in hard rocks causing their weathering.

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

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

Location	Do's'	Don'ts'
At home	Stand still near the corners of the house and sit under the table or any wooden furniture. Cut off the power supply at the time of an earthquake.	Do not run here and there and create chaos. Do not stand below heavy objects such as wall clocks, decoration pieces, photo frames etc.
In a vehicle or outside the house	Park the car in an open area and sit inside it. Find an open area away from tall building, trees or electric poles.	Do not stand near tall buildings, trees or electric pole.

C. Earthquake proof building has the follwoing specifications:

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

D. Effects of landslides are:

• Rivers change their course of flow
• Formation of artificial water reservoirs
• Huge traffic is build in the affected area
• Loss of life and property

E. 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. In the worst scenario, when the water pressure is very high, the water reaches the fault planes and lubricates them. 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.