The Arlington County School Board has begun inching forward in the process that eventually will determine how many, if any, of intermediate and high schools should be closed because of declining enrollments.

Last week, the board issued a preliminary report on school closures from Superintendent Larry Cuban and asked for public comment on it. The report outlines three options the board may take, all of which involve extensive citizen participation.

One option would rely heavily on information and recommendations developed by the administrative staff for public discussion; another on a committee of staff, students, the school board and civic groups, and the third on a special citizens' panel. All would entail public hearings at a number of stages.

Cuban also suggested the board might hire a private consultant to prepare recommendations, as Alexandria did in reviewing elementary school consolidations in 1973.

Copies of the preliminary report have been sent to PTAs and county schools. Written comments have been requested before the board meeting Feb. 19 when the issue will again be on the agenda. Any actual closings are not expected for a few years.

Cuban's report made no specific recommendations on which schools or programs should be consolidated. But the superintendent urged that the board determine by the end of the school year what process it will follow to resolve the consolidation issue.

The report includes enrollment figures at all county schools today and projected enrollments through 1985, which are expected to drop.