lecture #2

Question 1

What is drainage area?

Answer 1

Is the land area that is drained by all the tributary systems above a chosen point in the main channel

Question 2

What is discharge?

Answer 2

Is the volume of water passing through a channel per unit of time

Question 3

What is discharge related to?

Answer 3

It’s related to water velocity and stream cross sectional area

Question 4

How do we classify stream orders?

Answer 4

Smallest streams are assigned first order and the order increases when two streams of the same order join- is the strahler classification system

Question 5

What number of streams occur most often in a watershed?

Answer 5

low-order streams

Question 6

What comprises most of the length of a watershed? Low order or high order streams?

Answer 6

low order streams, even though high order streams are longer, because there’s more low order streams they make up most of the length

Question 7

What does perennial mean? Intermittent? Ephemeral?

Answer 7

Perennial means flowing all the time, excluding times of drought.
Intermittent means flowing some of the time and receiving water from groundwater.
Ephemeral means flowing rarely and not receiving input from groundwater.

Question 8

What kind of organisms would do good in Ephemeral streams? What kinds would do bad?

Answer 8

Organisms that need consistent water won’t survive well, organisms that go through diff life stages might for example frogs

Question 9

How can surrounding vegetation impact the stream?

Answer 9

As water drains through watershed, the water chemistry will be impacted as the water drains from surrounding vegetation.

Question 10

What is a riffle?

Answer 10

Is little waves, happens over gravel

Question 11

What is a pool?

Answer 11

is still water, happen over fine sediment

Question 12

How does composition of bottom of shape effect stream?

Answer 12

Effects flow of stream and shape of stream (depth)

Question 13

How does composition of stream bed effect stream?

Answer 13

shallow areas have ripples due to big boulders, deeper areas will have pools as we have finer sediments there

Question 14

Between the riffle and the pool what do you get?

Answer 14

runs, these are smooth running waters over a smooth surface

Question 15

What is a reach?

Answer 15

Is a section of river

Question 16

What is thalweg?

Answer 16

Is the fastest moving water, usually always on the outside edge

Question 17

Where is most of the erosion experienced in the stream?

Answer 17

At the outside bend of the river, on the other side sediments accumulate

Question 18

What is a point bar?

Answer 18

Is where sediments collect

Question 19

Meanders what over time?

Answer 19

exaggerate

Question 20

How does meander change with drainage area? Why?

Answer 20

The larger the drainage area the higher the meander will be

Question 21

Larger drainage leads to more discharge? T OR F?

Answer 21

T

Question 22

Total wetted width is what?

Answer 22

Adding all wetted widths

Question 23

What is bankful width?

Answer 23

Look at where there is high water marks, where there is change in vegeatation, a topographcal break from vertical to flat flood plain and from steep bank to more gentle slope, the highest elevation where there is no material below it and a change in texture of the deposited sediment

Question 24

What is channel slope?

Answer 24

Looking at how high banks are on each side

Question 25

What is maximum depth?

Answer 25

is highest depth of water in stream

Question 26

What is drainage basin length?

Answer 26

Is the straight line distance of the basin

Question 27

What is drainage basin land slope?

Answer 27

is slope of drainage basin

Question 28

What is drainage basin area?

Answer 28

area of drainage basin

Question 29

How does braiding occur?

Answer 29

happens over time and depends on substrate around river

Question 30

How does braiding influence stability of river?

Answer 30

it increases stability

Question 31

What is the best way to prevent flood?

Answer 31

a big floodplain

Question 32

What is a Wrybill?

Answer 32

Breeds only in braided rivers of New Zealand’s South Island, needs sediments ot make nest braiding provides habitats (has deeper pools, islands)

Question 33

What is a stream hydrograph?

Answer 33

it is a graph which shows discharge after rainfall

Question 34

How does urbanization effect discharge?

Answer 34

They cause peak of dishcarge to ahppen faster and amount to increase do to the impervious surfaces

Question 35

Why are wetlands positive?

Answer 35

they regulate flow of water
support important habitats
are important for biodiversity and ecosystem functioning

Question 36

What is the defn of wetlands?

Answer 36

Land saturated with water long enough to promote wetland or aquatic processes as indicated by poorly drainied soils, water loving veg, and various kinds of biological activity that are adpated to a wet environment

Question 37

Are wetlands conserved?

Answer 37

Are often drained, fille din or modified, 70% of wetlands were lost between 1940-80, most wetland loss is driven by agriculture with peatland being used for fuel and moss

Question 38

Ecosystem function and services for wetlands are what? 8

Answer 38

habitats for plants, animals, and regions of high biodiversity
Carbon storage
Cyclone and hurricane mitigation
high productivity
nutrient removal from water
biofuel creation
floor control

Question 39

How do wetland cover impact nitrate in water? crops?

Answer 39

They take up nitrate, crops increase nitrate