loading page

35-years decadal changes in planform morphology of the Niger and Benue Rivers confluence, West Africa
  • Muhedeen Lawal,
  • Kamaldeen Olakunle Omosanya
Muhedeen Lawal
University of Haifa

Corresponding Author:muhedeenlawal@gmail.com

Author Profile
Kamaldeen Olakunle Omosanya
Norwegian University of Science and Technology
Author Profile


In this study, time-lapse data covering 35 years record (1987-2022) of publicly available Landsat imageries and shuttle radar topography mission DEM are used to investigate the changes in planform morphology at the confluence of River Niger and Benue in West Africa. The confluence is flanked by high elevation areas, with the Niger, bordered by ca. 400 m high plateaus and low-lying floodplains on its western bank. Intra-channel and bank-attached bars are abundant in the Benue compared to the Niger. The confluence is segmented, and its tip records a net downstream migration of about 880 m in the last 35 years. With the confluence angle significantly reduced from ca. 175° in 1987 to ca. 500 in 2006 and ca. 16° in 2022. The abrupt drop in confluence angle between 1987 and 2006 reflects a marked increase in river runoff in the study area. Expansion along the banks of the Niger, Benue, and post-confluence rivers is low and non-uniform, signifying resistance of the banks to erosion due to the vegetated nature of the banks. These decadal changes in confluence planform were triggered by dislodgment and erosion of parts of the confluence, upstream erosion, and downstream migration of bars. Decadal morphological changes observed at the confluence of the River Niger and Benue are important for sustainable planning and for understanding river confluence dynamics in and around major rivers worldwide.