The General Assembly, in order to insure continuity of State and local governmental operations in periods of emergency resulting from disasters caused by enemy attack, shall have the power and the immediate duty (l) to provide for prompt and temporary succession to the powers and duties of public offices whose succession is not otherwise provided for in this Constitution, of whatever nature and whether filled by election or appointment, the incumbents of which may become unavailable for carrying on the powers and duties of such offices, and (2) to adopt such other measures as may be necessary and proper for insuring the continuity of governmental operations. In the exercise of the powers hereby conferred the General Assembly shall in all respects conform to the requirements of this Constitution except to the extent that in the judgement of the General Assembly so to do would be impracticable or would admit of undue delay.