This is the bread and butter of the party's support, if it cannot perform in times of crisis, it's existence is in question.
I'm sure you have heard of the concept of mandate of heaven and how in Chinese history numerous dynasties and emperors were thrown by the way side because they failed to act decisively to a natural disaster (Yuan dynasty is one example there are others) and were thus seen as having the mandate of heaven resined.
I believe that the same concept goes on today and explains why the CCP throws every available asset at natural disasters and anything that resembles a natural disaster. The CCP has no doubts about who were the balance of power lays, and it lays with the people. I won't say that China is a democratic but I will say that the government pay very very close attention to the wishes and whimes of the people.
An old Chinese proverb
水能载舟,亦能覆舟 (pinyin: shuǐ néng zài zhōu, yì néng fù zhōu)
Literally: Not only can water float a boat, it can sink it also.
Moral: The people(water) can raise someone(boat) to power, but can also take it away(sink).