- English
A common phenomenon associated with alluvial rivers is their meander evolution, eventually
forming cutoffs. Point bar deposits and ox-bow lakes are the products of lateral bend
migration and meander cutoff. The present study focuses on identifying the meanders of
River Manu and their cutoffs. Moreover, this study compares the temporal evolution and predicts
the progress of selected meanders of River Manu. In the present research, the Survey
of India topographical map, satellite imagery, and geographic information system (GIS)
technique were used to examine the evolution of the Manu River meander. Subsequently, a
field visit was done to the selected cutoffs and meanders of River Manu to ascertain the
present status and collect data. It has been observed that many cutoffs have undergone
temporal changes, and their sizes have decreased. Some have become dried or converted
to agricultural fields. The width of River Manu has decreased in all the selected bends from
1932 to 2017. The sinuosity index has changed from 2.04 (1932) to 1.90 (2017), and the
length of the river has decreased by 7 km in 85 years (1932–2017). The decrease in length
is evident from lowering the number of meanders. Uniformity coefficient and coefficient of
curvature of the bank soil samples were calculated, indicating that the soil is poorly graded
and falls under the cohesionless category. Based on cross-section analysis, sediment discharge,
grain-size analysis of the bank material, channel planform change, and radius of
curvature, it can be stated that almost all the selected bends have the probability of future
cutoff. The highest probabilities were observed in bend 3 (Jalai) and bend 4 (Chhontail). This work is aimed to provide planners with decisions regarding the construction of roads
and bridges in areas that show the huge dynamicity of river meandering.
- English
