Geomorphology - 6 Flashcards
Anthropocene
New interval of geologic time to account for the dominant and overwhelming influence of humans
Various starting dates
1610, 1960
Assessing anthropocene
Needs a workable distinction between human and non human process or madd transport dominance
Dominant human activities mean
They are over 50% outcome determination
How have geomorphists tried to compute anthropogenic processes?
By taking the difference between natural (geological) and human impacted (e.g. agricultural) estimates of soil erosion or fluvial transport
Requires comparative data and involves several assumptions
Limitations of measuring natural erosion rates
- in order to compute anthropogenic process rates
Assumption of naturalness
Limited sample size
Non anthropogenic climate change
Unknown temporal scales
Anthropogenic influences on aeolian environments
Directly and indirectly changing that erodibility of sediments that are suitable for wind transport
Vegetation and land cover changes influences dust fluxes
Dune systems tend to be stabilised but remains vulnerable to human impacts
Can manage them if complex influences and responses are understood
Anthropogenic influences on fluvial environments
Indirectly through land use changes that modify flow discharge, sediment load and river system connectivity
Directly through mining activities and various forms of river management
Approaches to monitoring human fluvial impacts:
- monitoring changes to spatial patterns
- identifying and dating strategic markers of human impacts
- quantifying long term sediment fluxes
- modelling catchment scale river responses
Anthropogenic Landforms
Rice terracing
Urbanisation e.g Manhattan island
Auto mapping
Mapped distribution of artificial ground, classified according to enhanced classification scheme Where criteria for mapping: class, type, unit
E.g. Liverpool Uk
Criteria for automated mapping
Boreholing Remote sensing Extract information for land use Land use change Man made ground/sediment
ARTIFICial land ground class = most dominant feature
Implications across process domains
Fluvial and coastal deal with Human influences acroas it’s landscape
Aeolian geomorphologist recognise increasingly influenced by human activities
All process domains influenced by anthropogenic influences, anthropogenically driven climate change
Improvements of monitoring and measurement techniques to address:
Less obvious human effects, knowledge needed for mitigation to advise policy makers
Need to improve the criteria for diagnosing human impacts in the connectivity, integrity and resilience of critical zones processes
New way on conceptualising they role of humans both through processes and materials within an ecosystem
Brown
2016
2016
Brown
Human activities alter the boundary conditions of second order processes - sediment erosion, transport and deposition
Impact trajectory rates of processes (threshold, connectivity, energy fluxes)
Aeolian, fluvial, cryosphere (surface albedo) and coastal (increase coastal pop. Less sand)
Improved knowledge help to diagnose impacts on connectivity, integrity and resilience if critical zones
