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River Equilibrium in River Engineering

Master the techniques of achieving river equilibrium in river engineering with this free online course.

Publisher: NPTEL
This free online course will explain the conditions required for a river to reach a state of equilibrium. Study how to calculate the shear stress in river bends and how river systems are affected by the region in which they move, for example, river braiding. Research the exciting topic of river meandering and explore the detailed case studies on the Ganga and Kameng Rivers, which will pique your interest and keep you fascinated.
River Equilibrium in River Engineering
  • Duration

    1.5-3 Hours
  • Students

  • Accreditation






View course modules


A river’s life has one resolve: to find a way to flow to the ocean with the least amount of work. This route of least effort is the river’s equilibrium state. Often, this state is not achieved for hundreds of years, even since when the river began.  Any river in the world starts at a high altitude and moves down the slope until it reaches the sea at zero elevation. Along the way, a river does plenty of work. In the upper reaches of the river, it flows very fast. The river is young, has a reasonable amount of water with it, and has gravity. The river hurries down, creating rapids in many places. It also erodes its trail heavily, creating hills on its banks and valleys in its path. It travels down steeply formed features to form waterfalls until it reaches a more level plain where the river tends to cool off. It has transported a lot of eroded material with it called sediment. This course on river equilibrium in river engineering will equip you with the relevant skills needed to minimise the effects of soil erosion.

First, you will discuss how a river can reach an equilibrium state where the balance occurs between the amount of sediment in the river and its capacity to carry that load. Case studies are used to predict the amount of erosion that can happen in a river system. The course will explore the challenging task of designing stable alluvial rivers, including the significance of channel cross-section and the channel’s slope. The result is that the river remains stable with no significant order of scouring or siltation taking place. You will also learn that proper observation and the iterative process of modifying the river’s profile are critical in achieving river equilibrium. This equilibrium takes place when there is a balance between the incoming and outgoing discharge. The sediment loads do not form scouring features, nor are there any sediment depositions along the particular river reach length.

Next, the course will discuss downstream hydraulic geometry and river meandering using mathematical equations and river surveys with an approximate value for velocity. River depth and width may be determined with only the perimeters of discharge, bed shear stress and the bed material. The course will outline how sediment load can also be measured using satellite imagery, how to analyse river bend characteristics in terms of the bend length, meander width, the radius of curvatures and the streamline deviations. This course will explain the use of case study examples, Lacey’s equations, and the regime relationship, which is vital in determining river behaviour under changing discharge. You will explore the side stability number’s value to show the ease at which braiding may occur in a river system. Knowledge of river equilibrium will give you, the learner, the confidence to take appropriate action to implement and solve fundamental river engineering problems. If you enjoy engineering, are studying environmental science, or merely love the idea of safeguarding our planet, then this course is for you. Don’t hesitate! Start today and become an expert in river sediment and equilibrium!

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