Any county having two (2) judicial districts and a population of fifty-six thousand, three hundred fifty-seven (56,357) according to the 1970 federal decennial census, together with any counties contiguous thereto, where the boards of supervisors of said counties, or any number of them, shall find and determine that the public convenience and necessity requires the same, as evidenced by a resolution duly adopted and entered on the official minutes of said boards of supervisors, may establish a planning, economic and industrial development council to be known as the "Southeast Mississippi Industrial Council," hereinafter called the "council." Said council shall be composed of three (3) resident citizens of each county participating in said council, who shall be qualified electors therein, appointed by the board of supervisors of each such county for terms of four (4) years, except as herein provided. Upon creation of said council, one (1) member shall be appointed from each county for a term of one (1) year; one (1) member shall be appointed from each county for a term of two (2) years; one (1) member shall be appointed from each county for a term of three (3) years. Any county becoming a participating member of the council after its creation shall appoint members in the same manner as set forth above. Each succeeding appointment to such council shall be for a term of four (4) years or until a successor is appointed and qualified.