Imiterere y’imisozi
Imiterere y’imisozi[1] yo mu Rwanda iranyuraranye. Uvuye i burasirazuba ugana iburengerazuba ubutumburuke buri hagati ya m 1000 na 4500. Iburasirazuba burangwa n’imisozi migufi, mu gihugu hagati n’imisozi iringaniye n’aho mu burengerazuba n’imisozi miremire.[2]
Isunzu rya Kongo Nili hindura
Ni uruhererekane rw’imisozi ifite ubutumburuke buri hagati ya m 2500 na 3000. Iryo sunzu ricuramiye ikiyaga cya Kivu, rigabanya amazi y’u Rwanda mu bice bibiri : amazi yisuka mu kibaya cy’uruzi rwa Kongo mu burengerazuba[3] n’amazi yisuka mu kibaya cya Nili mu burasirazuba. Isunzu rya Kongo Nili, mu majyaruguru hashyira i burengerazuba, higanje uruhererekane rw’imisozi y’ibirunga bitanu harimo ikirunga kibisumba byose aricyo Karisimbi gifite ubutumburuke bungana na m 4507.[4]