The number of Americans registered for federal disaster aid jumped tenfold this year, costing billions of dollars in additional emergency funding as the nation nears the end of a historically calamitous year.

More than 4.7 million Americans — about 1.4 percent of the population — have registered so far this year for disaster aid from the Federal Emergency Management Agency. In 2016, 480,000 sought aid, and fewer than 180,000 people registered for disaster assistance in each of the three previous years.

Three hurricanes — Harvey, Irma and Maria — collectively affected an area with about 8 percent of the U.S. population. The hurricanes were followed by wildfires that killed 43 people and destroyed more than 7,000 homes in California wine country.

The record-setting ­disasters — combined with other storms, floods, mudslides and blazes that struck communities across the United States this year — have taxed emergency resources and left residents struggling to rebuild their lives long after the floods have receded and the fires are out.

The fallout will cost taxpayers tens of billions of dollars, much of it approved by Congress in supplemental spending bills. The White House on Friday asked Congress for an extra $44 billion in disaster relief; FEMA would get the majority of that, and much of the rest would be for a community block grant program.

FEMA has enlisted private phone-bank companies and employees from other federal agencies, including the Internal Revenue Service, to add 3,000 staffers to process disaster claims.

In light of this challenging year of catastrophes, federal emergency officials are calling on Americans to improve their disaster preparedness.

“You have to know the hazards and vulnerabilities, and how to be prepared, based on where you work and where you live and where you visit,” FEMA Administrator Brock Long said in an interview.

FEMA has been using satellite imagery and other kinds of remote sensing, along with flooding data and housing records, to help calculate the cost of the damage suffered by disaster survivors.

But a dismaying development has slowed these efforts: Identity thieves are filing fraudulent claims.

Hackers have used the names of real victims to divert aid to bogus bank accounts. They struck first in California — filing thousands of fraudulent claims — and the scam spread to other disaster areas, FEMA Region IX Director Bob Fenton told the Post. He said that the agency’s inspector general is investigating the fraud and that the legitimate survivors will still get their financial assistance. But thieves already have siphoned away some of the money.

“There is funding that has gone out fraudulently to ­individuals who have committed this,” Fenton said.

As the government processes claims and helps people rebuild, FEMA officials say the disasters of 2017 should prod everyone to improve their readiness for a bad day. But they know that many people assume that certain hazards do not apply to them.

Long, the FEMA head, has called for a “culture of preparedness” and says Americans are nowhere close to achieving that.

He and other emergency managers talk often of having contingency plans for when existing systems break down.

That is especially important for families that include children or the elderly. The majority of people killed in the Northern California wildfires last month were elderly. In Florida, 14 elderly people died in a rehabilitation center that lost its air conditioning in a power failure caused by ­Hurricane Irma in ­September.

Long has urged people to create their own rainy day fund, and he says “asset poverty” remains one of the greatest impediments to true preparedness. A huge percentage of Americans cannot put their hands on $500 in an ­emergency, he said.