As a result of inflation, in general, and rising gasoline prices and airline fares, in particular, Americans probably will be taking fewer vacations this year. And people will be spending vacation cash closer to home than before.

In fact, 75 percent of the people surveyed in a recent Gallup Poll say they are not planning to take a summer vacation, and a third of those who are taking vacations say they will go to a local resort rather than traveling far from home.

There is good news and bad news in that for the $1 billion Washington tourist industry, which hosted about 12 million out-of-towners last year. The advent of the thrifty vacationer could bode well for the Washington tourist, which clearly benefits from the fact that about 5 million persons live within an hour of the city, with another 30 million within five hours of the District.

On the other hand, whether those people fill Washington hotels during the usually busy spring and summer is another question. So the Hotel Association of Washington and its members have started a major campaign to bring people, especially those along the East Coast, to the District. "Collectively and individually we have beefed up our advertising efforts," says Leonard Hickman of the association.

The theme of the effort is "Monumental weekend on just a little capital," and it is designed to bring people here to take advantage of weedend lodging packages.

"People don't understand that we're not jammed up on weedends," Hickman said.

So far, however, tourist industry experts say the industry will have a soft spring and summer. Already, hotel occupancy is down about 12 percent for the first two months of the year, with March just a bit better.

Those figures reflect scant personal budgets and increasingly tight corporate travel budgets. "Some of the companies that would have sent people are not," says Hickman. "Some that might have sent more seem to be sending less."

"Business is still good," said Austin Kenny of the Washington Convention & Visitors Association. "But it is awfully tough to judge a 4 or 5 percent decline."

George Fleishell, manager of Scholl's Cafeteria at 14th and K street NW, a popular tourist eatery, said he sees a growing number of tourist cancellations, changes in plans he attributes to the economic situation.

"We're about even with last year," Fleishell said. "But there are fewer tour buses, and schools are canceling out. We don't usually get a reason for the cancellations, but the economy is obviously why."

Although ridership on Tourmobile sightseeing vehicles is slightly up over last year, Tom Mack, the firm's vice president, is concerned about the summer."Sure, I'm worried," Mack said. "People seem to be altering their vacation plans."

Like hotels, Tourmobile is advertising more this year, continuing to train employes extensively and painting and remodeling buses.

Another student of the tourist industry notes that during the 1973 Arab oil embargo, the public spent vacation dollars closer to home than ever before. If that trend repeats itself this summer, remote spots, such as most national parks, might show a considerable decline in visitors.