Savannah and park forest vegetation predominate north and south of the equatorial forest belt; the southern savannah belt is far more extensive than the northern one. All major rivers are tributaries of the Zaire; these include the Lomani, the Aruwimi or Ituri, the Itimburi, the Mongala, the Ugangi, the Ue'le', the Kasaim the Sankuru, the Lulua, the Kwango and the Kwilu. The largest lakes include Tanganyika, Albert, Edward, Kivu, Mweru, Leopols II and Tumba.