Lecture #3

Question 1

What does flow give us?

Answer 1

The Force and Energy for sediment transfer

-Helps determine what the river channel looks like and how it works

Question 2

Is discharge dependant or indépendant of the channel?

Answer 2

Independant, it is imported from the watershed

Question 3

Can he river channel decide how much water its going to get?

Answer 3

No, it can determine the flow characteristics only,

-River channel its self doesn’t determine the discharge at any particular time

Question 4

3 Characteristics of discharge?

Answer 4

• Independant
• Varies over time at any given location
• Varies along the river system at anytime

Question 5

What is Continuity?

Answer 5

Cant gain or lose mass over a short distance of the channel

-the discharge at one place is the same as the discharge a couple meters up the channel

Question 6

What happens to velocity of the cross section changes?!

Answer 6

-Velocity has to change as well

Question 7

Where is velocity measured?

Answer 7

Continuously measured at gauging stations

Question 8

What is Day Variation?

Answer 8

Daily inputs (they vary) and the river changes everyday

Question 9

If the same rainstorm occurs on 2 different rivers, are the characteristics observed going to be the same?

Answer 9

No, can expect different catchments to show different characteristics and discharges

Question 10

What is Annual Variation based on?

Answer 10

Climate and Vegetation in surrounding area

Question 11

What are the peaks in hydrographs?

Answer 11

Rainstorms

Question 12

What are the 3 main stages in the Hydrographs?

Answer 12

• Rising
• Peak
• Returning to base flow

Question 13

Why is peak flow important?

Answer 13

It does a lot of geomorphic work on the channels

Question 14

What happens to discharge as you urbanize rivers?

Answer 14

Discharge increases, because of the bigger basin areas

Question 15

What is flood frequency?

Answer 15

The probability of occurrence
-Highest flows have the lowest probability
Discharge=flood

Question 16

Which modifies the channel more; big floods or littler ones?

Answer 16

• Big floods can modify the channel a lot but they are rare

- Littler ones happen more often and might be more important because it could do work just over a longer period of time

Question 17

What is a flood duration curve?

Answer 17

Frequency distribution of daily flow values over a given time
-Takes all the values for everyday.

Question 18

What is a flood record?

Answer 18

The highest flow every recorded for the period of time

Question 19

What is Hydraulic Geometry?

Answer 19

Describes the way in which the discharge is distributed within the channel, what it does to the flow characteristic of a channel

Question 20

What 3 variables are dependant on Q?

Answer 20

w v d

• Dependant on one another
• Relationship between the 3 is the hydraulic geometry and are responsible for the characteristics of the channel

Question 21

Who are the fathers of fluvial geomorphology?

Answer 21

Leopold & Maddock

Question 22

Out of w v d, which are the highest values?

Answer 22

v > d > w

-they all vary within a narrow range

Question 23

What is bed shear stress?

Answer 23

Flowing water exudes a force not he ned and river channel which does most of the work to move sediments

Question 24

What does the calculation for bed shear stress depend on?

Answer 24

flow depth and water surface

-other # are constants

Question 25

What is stream power?

Answer 25

The rate of potential energy expenditure

Question 26

What is specific stream power?

Answer 26

Stream power/channel width

-independent of the size of the river