The study of hydronyms is intimately connected with the ancient civiliazations of the world, which mostly flourished in the prominent river valleys in different historical epochs. Hydronyms are broadly categorized into two categories: Natural Hydranyms and cultural Hydronyms. Here natural hydronyms are those which are made by nature and cultural hydronyms are generally men made. The common prefix words for hydronyms or river names in Assam are: Di, Dui, Doi, Lang,Nam, Tui, Ti, Um etc. The suffix words for natural Hydronyms are: anga, Cherra, Chora, jan, juri, jola, jol, joli, juli, jota, jhor, nad, nadi, noi, nail, nan, nala, sol, sola, and suli;doba, ghuli, hawar, kunda, kupa, sarovar and so on

.