Kogin Mandyani kogi ne na kudu maso yammacin babban yankin Equatorial Guinea. Ya zama wani ɓangare na Muni Estuary tare da Kogin Mitong, Kogin Congue, Kogin Mitimele, Kogin Utamboni da Kogin Mven. Hughes, R. H.; Hughes, J. S. (1992). A Directory of African Wetlands. IUCN. p. 501. ISBN 978-2-88032-949-5. Retrieved 30 March 2012. Sundiata, I. K. (1990). Equatorial Guinea: colonialism, state terror, and the search for stability. Westview Press. p. 6. ISBN 978-0-8133-0429-8. Retrieved 30 March 2012.