there are already charities that are working with bitcoin to help in cases like this. it is up to people to donate if they like and these organizations to focus their help to specific disasters.
one that comes to mind is
https://www.bitgivefoundation.org/ which i believe was using bitcoin and the blockchain of it to reach transparency in the transactions and how and where are the funds being spent.
As far as I can tell, bitcoin charities have pineapple funds and the Pineapple Fund is not the only bitcoin charity in the world. Other Bitcoin-based charities are BitHope, a Bulgarian non-governmental organization, and BitGive and CommonCollection.