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Human Interaction with Surface Processes Human activity impacts on surface processes - Leaving Cert Geography - Question 2C - 2021
Question 2C
Human Interaction with Surface Processes Human activity impacts on surface processes. Examine this statement with reference to one of the following: • The impact ... show full transcript
Worked Solution & Example Answer:Human Interaction with Surface Processes Human activity impacts on surface processes - Leaving Cert Geography - Question 2C - 2021
Step 1
The impact of flood control measures on river processes
Answer
Flood control measures, such as levees and flood walls, significantly alter river processes. These structures are designed to protect areas from flooding, but they can also disrupt the natural flow of rivers.
Impacts on River Processes:
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Altered Flow Regimes: Flood control measures can lead to increased flow rates during periods of heavy rainfall, as water is channeled away from flood-prone areas. This can result in erosion of riverbanks downstream, increasing sediment transport.
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Habitat Disruption: Natural habitats along rivers can be destroyed by flood control measures. Aquatic ecosystems rely on fluctuating water levels, and the presence of levees can prevent the natural flooding that supports diverse plant and animal life.
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Sediment Transport Changes: The restriction of natural floodplain access impacts sediment deposition patterns, leading to possible riverbed degradation and increased transportation of sediments downstream.
Example: River Shannon in Ireland
The River Shannon has seen extensive flood control measures that have affected its natural ebb and flow, leading to increased erosion in certain areas and loss of riparian habitats.
Step 2
The impact of coastal defence measures on coastal processes
Answer
Coastal defence measures, such as sea walls and groynes, are implemented to protect shorelines from erosion and flooding.
Impacts on Coastal Processes:
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Erosion Control: While these measures protect specific areas, they can lead to increased erosion in adjacent zones, as natural sediment movement is disrupted.
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Sediment Accumulation: Groynes can create areas of sediment buildup on one side, altering the shoreline and potentially causing it to extend seaward.
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Wave Reflection: Sea walls often lead to increased wave energy in front of the structure, which can intensify erosion at the base of the wall itself.
Example: The Sussex Coast
Along the Sussex coast, sea walls have been installed to protect urban areas. However, these interventions have resulted in increased erosion further along the coastline, demonstrating the complex interplay of human activities and natural coastal processes.
Step 3
The impact of human activities on mass movement processes
Answer
Human activities significantly influence mass movement processes, especially through construction, deforestation, and land use change.
Impacts on Mass Movement Processes:
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Increased Stability Loss: The removal of vegetation and soil during construction can increase the risk of landslides, as plants help to stabilize the soil.
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Hydrological Changes: Urbanization alters drainage patterns, leading to water accumulation in certain areas. This increased water saturation can trigger landslides, particularly in hilly regions.
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Artificial Modifications: The alteration of slopes for roads and buildings can introduce instability, increasing susceptibility to various types of mass movements.
Example: The hills of San Francisco
In San Francisco, human-induced changes to the landscape have led to several significant landslides, showcasing the direct relationship between human activities and mass movements.