Slope
a)    Side of a hill or a mountain. Where the idea of orientation is intended, the word versant has to be used (geographic term).
b)   The inclined face of a cutting or canal or embankment.
c)    Inclination from the horizontal. Measured as the ratio of the number of units of the vertical distance to the number of corresponding units of the horizontal distance. Used in English for any inclination: Expressed in percent when the slope is gentle; in this case also termed “gradient ’.

(see also chapter Dam terminology)

Karstic channel or Solution channel - Tabular or planar channel formed by solution in carbonate rocks, usually along joints and bedding planes. It is the main water carrier in carbonate rocks.

Catchment - The area which drains naturally to a particular point on a river.

Catchment boundary - The boundary or pe­rimeter of the catchment

Watershed or Divide - The divide or boundary between two catchments.

River basin - The total basin drained naturally by a river.

(see also Shifting of the bed; shifting of the main channel)

Axis of stream - Line joining the mid points of the surface of the stream at successive cross-sections.

Axis of streambed - Line joining lowest points of streambed at successive cross-sections.

(see also Change of course)

(see also Bund)

Thalweg - The locus of the deepest points in a valley at successive cross-sections.

Bank - The term Bank with regard to a river is equiva­lent to the term Shore with regard to a sea or lake. Either the term Bank or Shore can be applied to a re­servoir impounded on a river.