Zaire became the democratic republic of the congo when mobutu sese seko took power belgium granted independence to its colony laurent kabila took power shaba changed its name to katanga

Zaire became the Democratic Republic of the Congo when Laurent-Désiré Kabila took power. 

Zaire, or the Republic of Zaire, was the name for the Democratic Republic of the Congo between 1971 and 1997 in Central Africa. The country was held by a dictatorship, run by Mobutu Sese Seko. Zaire was established after Mobutu's seizure of power in a military golpe in 1965. Zaire had a strongly centralist constitution and foreign assets were nationalized. 

Zaire become the Democratic Republic of the Congo when Laurent-Désiré Kabila took power in 1997, establishing the new Democratic Republic.

Cause of he different elevations  hope this ?