Atakan Karaman 18/03/2013
Discuss how the Bradshaw model can be used to model the fluvial characteristics of a river. (10 Marks)
The Bradshaw model is a geographical model that shows us how the characteristics of a river changes between upstream to the downstream. The Bradshaw model allows us to see do the river’s characteristics such as, average velocity, channel depth, load quantity and particle size of the load, increases or decreases and how much do they change. However this model can’t be exactly right for all rivers around the world because of the external factors that effects the rivers.
Average velocity is basically the speed of the water flows in that river. According to Bradshaw model average velocity increases from upstream to the downstream. Because velocity of the river influenced by the channel shape, channel slope and cross sectional area and channel bad roughness. For example channel bad roughness decreases from upstream to the downstream and therefore velocity increases. However there can be other factors that influence the velocity of the river such as people can build dens on the river. And this shows Bradshaw model can’t be 100% reliable.
Discharge is the volume of water that passes through a cross sectional area in a certain amount of time. According to the Bradshaw model discharge is one of the most sharply increasing characteristics of a river. The main reason of this increase is the tributaries of the river because so much water joins to the main channel from the tributaries to the river during the flow. However urbanization can also be effective on this characteristic because people can take away the water from the river and this decreases the discharge.
Load Quantity of a river defines as the total load of all sizes in a river. Load quantity also increases through the