Dorothy Johnson Orchard, 83, a native of the Washington area who was active in Democratic Party affairs in Arlington and the Society of Women Geographers, died Wednesday at the Sleepy Hollow nursing home in Annandale. She had cardiovascular ailments.

Mrs. Orchard was born in Alexandria and graduated from the old Central High School in Washington. She earned a bachelor's degree in mathematics at Swarthmore College. From 1918 until her marriage in 1920 to Dr. John E. Orchard, a professor of economic geography at Columbia University, she taught at old Western High School here.

From 1920 until Dr. Orchard retired in 1960, the couple lived in New York City. They traveled widely, principally in China and Japan, and Mrs. Orchard assisted her husband in many aspects of his work. For two years, they lived in Paris, where Dr. Orchard worked for the Marshall Plan. In 1960, they retired to their property at Lincoln in Loudoun County, Va.

In 1962, Dr. Orchard died and two years later Mrs. Orchard moved to Arlington, where she took part in Democratic Party affairs. She also was a member of the Society of Women Geographers. She moved to the Sleepy Hollow nursing home in 1978.

Survivors include three sisters, Carolyn J. Craighead of Naples, Fla., Pauline J. Zirpel of Washington, and Catherine V. Johnson of Alexandria.