Offtake Morphology and Conveyance Characterisitcs of a River

The river-bifurcation point namely the ‘Offtake’ is vital for the sustainability of a river. The sustainability also depends on the conveyance characteristics of the river-reach as a whole. This book presents the hydro-morphological analysis of the offtake and the river-reach of the Arial Khan River of Bangladesh to predict its sustainability. Analysis of historical hydrometric data and satellite images near the offtake and selected stations for both the parent Padma River and the distributary Arial Khan River has been carried out. The analysis shows that water levels and discharges are in rising trend in both the rivers. The offtake and remaining reach of the Arial Khan River which are observed to lose conveyance due to aggradations. Also, the conveyance in the reach of parent river, the Padma around the offtake and the remaining reach of the Arial Khan River was found to have a decreasing trend. The yearly development rate of char (sand bar) at the mouth of the Upper Arial Khan River is 2%. The study indicates that the sustainability of the Arial Khan River including its offtake is endangered and it is going to be the cause of sufferings to the local livelihood.