Anthropogeomorphology Flashcards

(36 cards)

1
Q

Viles quote on anthropogeomorphology

A

‘Human impacts and geomorphology are all-pervasive and geomorphology textbooks need re-writing’

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2
Q

what are the two types of effect that humans can have?

A

Cumulative
Systematic

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3
Q

what is a cumulative impact?

A

building up of impacts across the world that add up to response in global systems
(eg. shaping river channels, coastal protection and quarrying)

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4
Q

what is a systematic impact?

A

whatever we do has an almost instantaneous effect on global change
e.g. climate change

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5
Q

Quote for anthropocene- and name/date

A

Steffen, 2010

Anthropocene is an epoch when human activities have ‘become so profound and pervasive that they rival, or exceed the great forces of Nature in influencing the functioning of the earths system’

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6
Q

Why is there contestation over when the Anthropocene started?

A

Because 3 potential stages:
Paleoanthropocene
industrual era
Great accelleration

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7
Q

how much sand is extracted each year?

A

50 billion tonnes

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7
Q

what is the use of sand?

A

concrete
microchips
glass

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8
Q

Effect of cities on geomorphology?

A

air pollution
enhanced surface relief - complex topography that influences wind flow and microclimates
concrete = decreased surface permeability
Tunnelling/ sewers and extraction of groundwater = cause surface instability
New sinkhole method of formation nothing to do with limestone

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9
Q

example of anthropogenic sinkhole

A

Guatemala City, 2010
rain from tropical storm Agatha
alongside volcanic eruption and leakage from sewer pipes created giant sinkhole in the city

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9
Q

Who coined the term ‘Anthropocene stream’ and what is this?

A

Merrits et al (2011)
a stream characterised by deposits, forms and processes that are the result of human interface

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10
Q

Explain the effects of deforestation on meanders

A

trees encourage stable meanders through mechanical stabilisation of river channels and retention of sediment that can create flood plains
Continued removal of trees is reverting some river landscapes to pre-vegetative conditions where sediment and the river channel were more mobile
both vegetated and barren landscapes exhibit meanders - vegetated just more stable
river deforestation increase rate of channel migration

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11
Q

Horton et al date?

A

2017

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12
Q

example of effects deforestation on meanders- study

A

Horton et al (2017)
Kinabatangan River in Malaysia -
huge areas of forest around the river cleared for palm oil monoculture production
using satellite imagery - channel migration rates calculated as 23% quicker than in areas that still remained vegetated

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13
Q

what research suggests afforestation is not effective?

A

Buechel et al (2022)
used uk land simulator to model the effects of large scale afforestation in Great Britain
found that whilst afforestation actively increases channel stability the growth in vegetation may also reduce water availability (due to increased interception and transpiration)
concern in drier areas where water is already a limited resource

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14
Q

Research onto significance of tree species in reforestation-

A

Qian et al (2024)
found that effective tree planting is also dependent on the three species planted
using native tree species increases soil nutrition and stabilises river banks for longer periods of time than non-native species

15
Q

Name of study that discusses the effect of animal extirpation from fluvial landscapes?

A

Beschta and Ripple (2006)

16
Q

explain the Beschta and Ripple (2006) wolves study

A

removal of wolves from the Gallatin River basin in early 1900s
Grey wolves hunted and trapped and poisoned = leaving elk population to rise without predation
elk roam river banks decrease vegetation coverage - specifically willow trees
willow trees provide stability for river channels = roughness of above ground stems reduces water velocities and increases deposition also root systems are deep
acceleration of erosion has led to channel widening, incision and avulsion
also decreased hydrological connectivity

17
Q

study on repatriation of salmon into habitat?

A

MacDuff and Bauer (2018)

18
Q

explain MacDuff and Bauer (2018) study?

A

highlighted that repatriation of species back into habitat is not as simple as just putting them back - prior reconstruction of the river to pre- anthropogenic conditions needed

Study of salmon in Lower Vernon Creek BC , Canada
Due to construction of McIntyre Dam prevented the movement of fish between mainstream lakes and tributaries
saw 90% decrease in spawning
modelling found that only a small fraction of the river is actually viable for reintroduction of salmon as bed material changed size - now too heavy for salmon to move during nesting and water velocity too fast
re-meandering to slow water velocity and control sediment size needed

19
Q

Study to support the effects of dams on river geomorphology -

A

Skalak et al 2013
River damming has increased the mean residence time of river waters from 16 to 47 days and increased the volume of water by more than 700%

20
Q

damming has increased voume of water by what percentage

21
Q

damming has increased mean residence time of river water from _____ to ______

A

16 to 47 days

22
Q

Dams effect on river form

A
  • prevent flow of sediment causing accumulation of material upstream and sediment starvation downstream
  • downstream areas experience heightened rates of erosion resulting in channel incision
    erosion increased further by straightening of channel causing higher river velocity
23
Dams effect on formation of floodplains
reducing frequency of flood events less material is deposited into the flood plains causing them to shrink and biodiversity to decline
24
how much river do the EU biodiversity strategy aspire to remove dams from by 2030?
25, 000km
25
What are nature based solutions?
management strategies that aim to protect or conserve ecosystems and their biodiversity whilst also addressing social and economic challenges
26
How do nature based solutions apply to rivers?
Consider river as a dynamic whole acknowledgement that they can provide benefits for both people and nature
27
Example of a nature based solution
The Eddleston project funded by the Scottish government at the start of the 19th century the river was straightened combined with the building of railway embankment and intense agricultural practice led to increased flood risk and biodiversity loss downstream rather than impose hard engineering infrastructure to mitigate flood risk - use river re meandering, new wetland creation and tree planting to decrease river velocity
28
How much has flood risk decreased by since Eddleston water project started?
30%
29
what holds back environmental management strategy ?
- continuation to view rivers as static and segmented capitalist culture prioritising quick economic growth over long term sustainability governments and organisations often avoid publicising research that suggests more expensive and complex understandings of environmental management as doesn't fit the 'business model'
30
what is Enhanced Rock weathering?
strategy that takes carbons out of the air and storing it in rocks Grind rocks up making fine gravel or dust that reacts more easily with air or water eg. Olivine very common rock used because weathers so quickly and locks up carbon as it dissolves sprinkle over fields Atmospheric carbon reacts with the rock and is washed away into rivers and eventually oceans that lock carbon away
31
limitations of Enhanced Rock Weathering
energy intensive expensive some studies suggest that olivine may actually add co2 to atmosphere byproducts of mining harmful to ecosystems and health contamination of rock = can be toxic and dust spreads to agriculture dur to wind
32
Research into the city as an emerging landform
Dixon et al (2017) research has overlooked the ways that earth system processes can act on urban fabric to produce hybrid landforms research should consider urban fabric as an Anthropocene landform
33
warfare as an example of Anthropocene geomorphological processes -
high explosives in urban areas causes destruction of buildings and creation of rubble with a range of particle sizes
34
case study of warfare and geomorphology -
Dixon et al (2017) - warfare in Syrian city of Aleppo between 2011 and 2014 caused damage to 300,000 buildings - piles of rubble and debris accumulated - neglect and abandonment leave these new landforms to be shapes by aeolian, fluvial and biogeomorphological processes