Interior Secretary James Watt has ordered U.S. Park Police to crack down on drug traffic on federal parkland around the nation's capital, particularly in Northern Virginia along the George Washington Memorial Parkway.

The announcement of the creation of a new park police task force on drugs came yesterday from Rep. Stan Parris (R-Va.), who met Tuesday with Watt and Rep. Manuel Lujan Jr. (R-N.M.), the ranking Republican member of the House Interior and Insular Affairs Committee. Parris is on the House select subcommittee on narcotics and drug abuse. Parris said Watt "promised to do something immediately" after being shown park police reports documenting a rash of drug incidents this spring on National Park Service parkland in Northern Virginia. A group of park police officers went to Lujan's committee last month complaining about manpower cutbacks on the police force and increased drug trafficking here, which they claimed the park service is ignoring.

One officer reported witnessing about 60 persons at Fort Hunt--just north of Mount Vernon--buying and selling drugs at 2 a.m. one night last month, a spokesman for Parris said yesterday. The officer said he was told by his superiors to ignore it because there were insufficient officers available to back him up, the Parris spokesman said.

The officers also told the committee large numbers of syringes and drug paraphernalia are found almost daily at parkway overlooks along the Potomac River north of Key Bridge, particularly at one overlook near Langley.

Park Service Regional Director Manus J. Fish said Watt asked him Tuesday "to be responsive to the concerns" raised by the congressmen.

Fish said he and Park Police Chief Lynn Herring talked yesterday, and an increased--but unspecified--number of undercover officers will be assigned to combat drug problems, particularly in Northern Virginia, but also in parks in the District of Columbia. There is less federal parkland in suburban Maryland and little problem there now, Fish said.

Fish said there has been some increase in drug trafficking in federal parks this spring because a D.C. police crackdown on drug dealing has chased many drug dealers off city streets.

But Fish said he thought the drug problem is being exaggerated. He said he was unaware of the incident at Fort Hunt or daily problems at parkway overlooks and will investigate them.

Parris said yesterday, "We are putting out the word today that Virginia and the federal government will not tolerate the growing number of drug deals being made nightly in national parks in Northern Virginia." He added that he was particularly concerned "because some tourist family is going to get blown away when they accidentally stumble across a drug pusher."

A group of South Carolina schoolchildren and several hundred other tourists were witness to a shootout at the Washington Monument on the night of April 21, when park police fatally shot a man who allegedly had been following the school group and attempting to sell drugs to the students. The man shot one park policeman in the leg.

About a dozen officers visited Lujan's committee four days later. They claimed the park service had reduced the police force to 410 officers, 58 fewer than in 1980, at a time when drug trafficking and other crimes were increasing.

Fish said yesterday there are 48 fewer officers than there were in 1980 and that the reduction came through attrition and retirements because of federal budget cutbacks. He said the park service plans to hire additional officers, but probably not as many as 48, when money becomes available.