AvulsionThis beautiful gif was prepared using data from the long-lived Landsat series of earth orbit
AvulsionThis beautiful gif was prepared using data from the long-lived Landsat series of earth orbiting satellites, You are looking at the course of the Padma River in Bangladesh and how its course has varied over the last 30 years. This is a textbook example of river erosion processes. When rivers begin to meander, they evolve by growing their meanders wider, until the meander finally gets too sinuous and the river finds another path. Pick a point where the river bends and watch what happens – the outer bank of the river erodes and sediment deposits on the inner side of the curve, making the river arc farther outwards. The outer side of the river that is eroding is called a cut bank, and sediment is deposited on the inside of the river building a point bar.Once the river gets too sinuous or too bendy, the river will break its banks, straighten its course, and abandon the wide meander. This breakthrough into a straighter path is called an avulsion.Bangladesh is one of the most densely populated countries on Earth. In places, this river has rapidly widened, eroding outwards through lands that were once farmland or homes. The flow rates here are high, there are occasional floods, and the sediment surrounding this portion of the river is loose sand that is easily mobilized as the river migrates. The big avulsion that cuts off 2 meanders near the center of the frame is likely associated with a 1998 flood that forced large releases of water from an upstream dam.-JBBGif credit: https://go.nasa.gov/2MgpiLh -- source link
#science#landsat#river#padma river#bangladesh#erosion#cut bank#point bar