Long profile
A concave idealised path of a river from source to mouth
Cross profile
What a river looks like across its valley and channel
Cross sectional area
The width times the depth of a river - a 2D slice through a river
Discharge
The amount of water passing a certain point in a river every second
CUMEC
Cubic meter per second
Lateral erosion
The side to side erosion of a river
Vertical erosion
The downward cutting motion of a river in the upper valley
Upstream cross profile
Downstream cross profile
Middle valley cross profile
Source
Where a river starts, high in the mountains or at a spring
Mouth
Where the river end up entering into a sea or lake