hydrosphere

Question 1

describe the process of precipitation

Answer 1

Air rises, cools and saturates at dewpoint temperature. Upon further cooling, the water vapour in the air condenses into water droplets, which form clouds. The tiny water droplets coalesce to form bigger water droplets. When the water droplets in clouds get too heavy, they fall as precipitation

Question 2

example for floods

Answer 2

In 1999, a flood hit Venezuela in South America. About 650 people died, 150000 people became homeless and 7000 people went missing.

Question 3

example for excessive rainfall

Answer 3

Yangtze River and the Yellow River in China frequently overflow their banks after heavy rains because the rain washes large amounts of sediments into the rivers. These sediments are then deposited on the river beds, cusing the rivers to become shallower. With time, flooding occurs

Question 4

example for snow melt

Answer 4

In 1986, the St John River in Canada overflowed its banks as it could not hold the excess water from melting snow in its channel. Several homes became submerged in floodwaters and families had to be evacuated

Question 5

example for storm surge

Answer 5

More than 80% of Bangladesh sits on on low-lying floodplains of the Brahmaputra and Ganges Rivers. About 35% of the country is less than 6 metres above sea level. As such if it is frequently subjected to regular flooding caused by storm surges, when strong winds blow towards Bangladesh from the Bay of Bengal, flooding occurs.