Title River - Erosional_and_Depositional_features_of_a.pdf ✅

Erosional & Depositional features of a River By Mr. Ershad Ali Department of Geography Contact: +91 8967252423 Email: [email protected] Ananda Chandra College Jalpaiguri, 735101 West Bengal, India
Introduction • Definition of river • General definition: • According to Mary Marisawa: “A stream may be define as a channelized flow of water”.  According to Jackie Smith: A river is a large stream of fresh water flowing downhill within a channel to enter another river or a lake or sea. • Source of the River : Rainfall, Snowfall • River channel components 1) Width 2) Wetted perimeter 3) Cross sectional area 4) Water depth 5) Stream gradient
Fluid flow in open channel 1. Uniform flow 2. Non-uniform flow 3. Steady Flow 4. Unsteady flow 5. Rapid flow: Stream gradient 40 -50 degree 6. Ultra rapid flow : Stream gradient 60 – 80 degree 7. Renold number <500 = laminar flow >500 = turbulent flow 8. Froude number <1 = subcritical flow/ Tranquil 1= critical flow >1 = super critical flow