River Profile & Flow

Question 0

Gradient: irregularities may arise when

Answer 0

River crosses a boundary, such as between a hard rock and easily erodible rock.

Question 1

Gradient: can be measured at

Answer 1

Intervals from river source.

Question 2

Gradient: as the gradient lessens,

Answer 2

The valley widens.

Question 3

Gradient =

Answer 3

Difference in height (m) / distance (m)

Question 4

Speed of flow can be estimated by

Answer 4

The manning equation.

Question 5

Isobel lines are lines that

Answer 5

Connect points of the same water speed in a river.

Question 6

Longitude profile:

Answer 6

The elevation against distance from the source.

Question 7

Base level:

Answer 7

The lowest level of the river, cannot go any lower.

Question 8

Reynolds number: below 500 is

Answer 8

Laminar flow.

Question 9

Reynolds equation can be rearranged to

Answer 9

Find distance.

Question 10

Hydraulic radius (m) =

Answer 10

Area of cross section (m2) / wetted perimeter (m)

Question 11

Wetted perimeter (semi-circle channel) =

Answer 11

π r

Question 12

Area of cross section (for a semi circle channel) =

Answer 12

1/2 π r2