From Longman Dictionary of Contemporary Englishriver basinˈriver ˌbasin noun [countable] SGan area from which all the water flows into the same river
Examples from the Corpus
river basin• Another use of the simulation model might be to assess the effect of increasing the urban area lying within a river basin.• In the early 1940s, the Bureau devised the plan of considering an entire river basin as an integrated project.• A considerable amount of time and money has been spent in pursuing the study of river basin dynamics.• The results from the model can be used to answer questions relating to the long-term behaviour of the river basin.• The river basin is a well-defined spatial unit that is of great interest to hydrologists, geomorphologists and geographers. 