RS-GIS based assessment of the impact of Hatimura embankment on the channel planform of the Kolong River, Assam, India

Kolong River is recognized as an immensely degraded and flow deficit river of India. Installation of the Hatimura embankment as an ad-hoc flood control measure had restricted the entry of water into the river channel from its source thus converting it into a flow deprived polluted river. Significance of this study lies in the identification of the impacts of the Hatimura embankment on the planform morphology of the river. An attempt has been made in the present study to analyse the channel planform during the past 103 years (1912–2015). The river was found to be highly meandering with highest sinuosity index (SI) value of 2.18 observed during 1912. River planform seems to have a weak tendency of channel straightening, supported prominently by decreasing SI value from 1912 through 2015. The average migration rate of the meandering channel of the Kolong River was estimated to be 0.11 m y−1.