Lecture 2 - Sediment transport,

Question 1

Give three examples of mass wasting

Answer 1

Rock slide
Earth flow
Mud flow

Question 2

What three factors increase mass wasting events

Answer 2

1) composition of material
2) Amount of h20 present
3) angle of the slope

Question 3

What is meant by the angle of repose?

Answer 3

The angle in which the sediments will stack if dropped from a cosistant point above the center

Question 4

What are the triggers for mass wasting?

Answer 4

1) earth quakes
2) heavy rain
3) gradual over steepening of slope

Question 5

What effect did the building of the Vaiont Dam have with respect to the subsequent landslide

Answer 5

Effects magnified by the poor placement of the dam, killed 3000 people. Placement of the damn meant there was more pressure and the materials become more saturated. The ancient slide was ignored.

Question 6

What is the difference between tublar and laminar flows

Answer 6

Laminar flows are parallel stream lines and simple flow. Turbalant flows are cross cuting stream lines and complex flows

Question 7

What is suspended load

Answer 7

material suspended in the water istelf

Question 8

What is the bed load

Answer 8

The material that is being dragged along the bottom, sliding and rolling

Question 9

What is saltation?

Answer 9

Its the intermitant jumping of smaller rocks along the floor the river, grains are sucked up into eddies then moved further down and this repeats

Question 10

Explain entrainment

Answer 10

Bernoulli’s Principle, The sum of verlocit and pressure on an object must be constant, this causes the low pressure of top of the rock to make it rise.

Question 11

Define floodplain (river systems)

Answer 11

The area either side of the river which has been flooded before and may be again if flooding occours. Its a low land area.

Question 12

Define: Channel (river systems)

Answer 12

The main flow of water through an area such as river

Question 13

Dfine Levees (river systems)

Answer 13

When the river flood it deposites sediment either side of the river causing a slow build up of sediment on eithr side of the river bank

Question 14

Define Terraces (river systems)

Answer 14

If the land is uplifted the river channel will erode downwards. The old flood plane will then form a terrace

Question 15

Define: Alluvial Fan:

Answer 15

Fan shaped accumulations of sediment despoisted when a stream must suddelny adjust to a change in conditions, such as a mountain front

Question 16

Explain meandering river

Answer 16

Rivers that flow in an “s” shapped pattern, Can you draw the formation of an ox bow lake?

Question 17

explain a braided river system

Answer 17

Steams have many channels, the channels plit and then join. found where theere is a incosistant flow of water (such as the bottom of a glacier) and a high sediment load

Question 18

what is meant by the longitudinal profile?

Answer 18

Repsentative of a cross sectional view of the river

Question 19

What is meant by base level?

Answer 19

Lower end of the profile is known as the base level where the river enters the sea or a lake, here it cannot cut down any deeper.

Question 20

What factors effect the flooding

Answer 20

Climate and the width of the flood plain

Question 21

What would cause extreme flooding

Answer 21

Reduction in flood plain areas, massive glacial melt, standard GCSE stuff