River Sections and the Form of a Riverbed

  1. Brainstorm with students and list all different terms that are connected to the shape of a river (torrent, meander, delta,).
  2. Look at each of the terms and try to define its correct meaning. Then relate the term to the upper, middle, or lower sections of a river.
  3. Take the Worksheet “The shape of a riverbed” and have a discussion with students:
  • What are different types of riverbed? (Narrow rocky and steep, wide silty on vast plain, etc.)
  • Where does a specific type usually occur? (On different sections of a river from its source to its mouth.)
  • What determines a specific form of a riverbed? (The most important parameters are: slope, the quantity of water (discharge), type of sediments, etc.)
  • What are the characteristics of a river landscape when the water flow is fast? (The river water digs deep into the ground, washes away rocks and other material, and creates narrow valleys.)
  • What are the characteristics of a riverbed when the water flow is fast? (The riverbed is straight, narrow, steep and rocky with many cascades.)
  • What are the characteristics of a river landscape when the water flow is slow? (Valleys transform into a vast plain, and a river forms large meanders with islands and parallel branches. The water current constantly takes away material on the outside banks of meanders and deposits eroded material on the inner banks of meanders.)
  • What are the characteristics of a riverbed when the water flow is slow? (The riverbed is wide, almost levelled, with silty sediments that form marshy islands etc.)
  • Which part of a river is the richest regarding the diversity of plants and animals? (The lower section of a river with wide meanders, deltas, marshes and swamps is one of the richest parts of a river regarding biodiversity. It is a for numerous plant and animal species.)
  1. Take the Worksheet “The sections of natural riverbeds” and have students write the main characteristics of each section. They can work in groups.

 

References:

Adapted from Vahtar, M., Misdorf, R., (2005): Where Waters and Land Meet: Teaching material, Water, Water-Management and Coastal Zone Management Education in the Context of Regular Primary School Education. Institute for Integral Development and Environment, Slovenia and Netherlands Ministry of Transport, Public Works and Water Management, National Institute for Coastal and Marine Management (RIKZ), CZM Center, The Hague.