The federal government won two court victories yesterday in its efforts to curb environmental abuses by strip-mining coal companies.

Chief Justice Warren E. Burger temporarily set aside a ruling by a southern judge and granted federal officials permission to resume enforcing key provisions of a landmark 1977 law in Virginia. The law is designed to force strip miners to restore mountains damaged in the search for coal.

In a separate order, U.S. District Court Judge Thomas A. Flannery upheld the Interior Department's authority to issue stiff regulations to carry out the controversial 1977 law. Flannery held that state governments are required to meet minimum environmental standards set by the Interior Department under the strip-mining law.

Both court rulings centered on the Surface Mining Control and Reclamation Act, approved by Congress after years of sharp debate between environmentalists and coal industry supporters and two presidential vetoes. Legislation designed to weaken the 1977 law has already cleared the Senate and is under consideration by a House committee.

Environmentalists have argued that strip-mining controls are necessary to prevent flooding, landslides, soil erosion, water pollution and other environmental damage. The coal industry has contended that the regulations increase mining costs at a time when the Carter administration is pressing for a shift from cost oil to cheaper coal.

Burger's order, signed Monday night and made public yesterday, temporarily stayed, or set aside, a Jan. 3 decision by District Court Judge Glen M. Williams. Ruling in Abingdon, Va., Williams prohibited the Interior Department from enforcing key provisions of the 1977 law, declaring them unconstitutional.

Williams' ruling -- the first permanent injunction issued against the strip-mining law in the United States on constitutional grounds -- was stayed at least until Thursday, pending a further order by Burger or the U.S. Supreme Court. The Supreme Court is considered likely to consider the issue at its regular weekly conference on Friday.

Flannery ruled in a massive lawsuit brought by several states, including Virginia, 105 coal companies, the National Coal Association and the American Mining Congress. The industry contended that the Interior Department lacked authority to issue the regulations and that the regulations were too stringent.

Flannery split the suit in half, ruling yesterday on about 50 of the more than 100 strip-mining regulations challenged by the coal industry. He upheld the Interior Department's authority to issue the regulations, but asked the department to reconsider about 20 provisions. Flannery will rule on the other issues later.