You can challenge the same in consumer court as they need to refund the same

Dear Sir,

It is settled law that no one enrich on the funds belonging to others. The hotel has not served you and in other words you have not availed their services. They are bound refund. Get issue a strong legal notice.

After sending a legal notice for refund if not given. You need to file a complaint to district forum of the appropriate jurisdiction and contest the same. 

Non fulfilling of contract terms to the extent it is caused due to natural calamities can not make the defaulter responsible in any way. 

1) you are entitled to refund of money as you are unable to travel due to floods 

2) if hotel refuses you can file complaint seek refund of your money paid by you with interest 

Contact a local lawyer and file complaint before consumer forum 

We would advise you to file a complaint before the concerned Consumer Court seeking full refund. 

Dear,

       As this is natural disaster and not in your control, so you are eligible for full refund.

       First of all send legal notice through advocate for your refund money with interest and 

       the expenses you maid.

       If they are not refund money after that, file petition in consumer court. 

Cancellation depends on the policy or contract you have with the hotel, whether you have booked through any agency or book direct , if you book directly then ask the cancellation policy because it is all over world if they don't give then file a case before the Consumer Forum of the area for deficiency in service, for your convenience I am mentioning the policy of the agency called Clear Trip:

If you cancel your booking Online: If you cancel more than 24 hours notice you pay ZERO rupees as your cancellation fee. If you cancel within 24 hours before check-in, you will incur 1 room night charges from hotel and a separate cancellation service fee of Rs 300 from Cleartrip.

Above position is affected by force majeure, you are entitle to 100% refund. Issue legal notice - recovery through consumer court.

No they cannot refuse to refund the advance paid by if booking is cancelled due to natural disasters.

You can make complaint in consumer forum for refund of money from hotel. 

The situation is unavoidable and it is due to natural calamity or acts of God hence under this clause the hotel may refuse to refund the booking amount even if you have cancelled the program.

You may go through the refund clauses of the booking conditions.

Alternately you can issue a legal notice after getting confirmation from the hotel management in writing about non-refund, demanding the  booking amount through your lawyer.

After getting their reply you may plan to proceed further adopting legal steps or to forego the same considering various factors including the cost that may incur due to litigation expenses.