L.O: Investigate river variables that change from source to mouth. All MUST identify which variables increase and decrease (D). Most SHOULD explain the processes that affect these variables (C-B). Some COULD identify key river landforms Teachable and Ruth Edgar. Some rights reserved.

Rearrange the words below to define different river variables… 1. LCOETIYV 2. SICDREGHA 3. OALD (ZEIS) 4. ROCSS EOCNIATLS REAA 5. RCTINIFO 6. ARDGEITN7. AHNCENL GHOUSSREN Answers: 1. Velocity; 2. Discharge, 3. Load (size), 4. Cross Sectional Area, 5. Friction, 6. Gradient, 7. Channel Roughness Starter: Remember that using key vocabulary such as this is essential (AF7 – Effective Teachable and Ruth Edgar. Some rights reserved.

River characteristics vary as rivers move from source to mouth. Bradshaw was a river engineer who devised a model that can be applied to rivers. He stated that as a river moves downstream, some variables increase whilst others decrease. This side of the model shows the variables that are greatest/largest at the source of the river (the upper course). This side of the model shows the variables that are greatest/largest at the mouth of the river (the lower Teachable and Ruth Edgar. Some rights reserved.

Width x depth – a calculation of the total area of the river channel. The size of material and sediment carried in the water. The angle or slope of the river channel and surrounding area. The volume of water in the river channel. The quantity of sediment carried within the body of water. The ability of the river channel to move water and sediment. The amount of churned or fast pockets of water (eddies) within a river channel. The speed at which the water flows within the river channel. The smoothness of the river channel. The resistance that builds between the water and river Teachable and Ruth Edgar. Some rights reserved.

River VariablesDefinitionChange from source to mouth (increase/ decrease) Explanation Cross Sectional Area Load (size) Gradient Discharge Load (amount) Efficiency Turbulence Velocity Channel Roughness Teachable and Ruth Edgar. Some rights reserved.

River VariablesDefinition Change from source to mouth (increase/decrease) Explanation Cross Sectional Area Width x depth – a calculation of the total area of the river channel. Load (size) The size of material and sediment carried in the water. Gradient The angle or slope of the river channel and surrounding area. Discharge The volume of water in the river channel. Load (amount) The quantity of sediment carried within the body of water. Efficiency The ability of the river channel to move water and sediment. Turbulence The amount of churned or fast pockets of water (eddies) within a river channel. Velocity The speed at which the water flows within the river channel. Channel Roughness The smoothness of the river channel. Friction The resistance that builds between the water and river Teachable and Ruth Edgar. Some rights reserved.

UPPER COURSE LOWER COURSE On your copy of these two photographs, add annotations to show how the variables change from source to mouth: D-C = Label three key variables you can identify on each photograph. B = Describe how three key variables change between the two photographs. A-A* = Explain how three key variables change between the two photographs and how that has affected the size and shape of the river Teachable and Ruth Edgar. Some rights reserved.

L.O: Investigate river variables that change from source to mouth. All MUST identify which variables increase and decrease (D). Most SHOULD explain the processes that affect these variables (C-B). Some COULD identify key river landforms Teachable and Ruth Edgar. Some rights reserved.