Photo AI
Human activity impacts on surface processes - Leaving Cert Geography - Question C - 2017
Question C
Human activity impacts on surface processes. Examine this statement with reference to one of the following: ➢ The impact of flood control measures on river process... show full transcript
Worked Solution & Example Answer:Human activity impacts on surface processes - Leaving Cert Geography - Question C - 2017
Step 1
The impact of flood control measures on river processes
Answer
Flood control measures, such as dam construction, levee building, and river channelization, significantly influence river processes.
Identification of Impact
One major impact of flood control is the alteration of natural flow regimes. For example, building a dam can reduce the frequency and magnitude of floods downstream.
Examination of the Impact
This alteration affects sediment transport. Reduced sediment supply can lead to increased erosion downstream as rivers have less material to deposit. Furthermore, levees can create a false sense of security, encouraging development in flood-prone areas, potentially increasing risk during major flood events when the levees fail.
Diagram
A labelled diagram of a dam and its effects on river processes would illustrate these impacts clearly. It could show river before and after dam construction highlighting changes in sediment distribution and flow patterns.
Step 2
The impact of coastal defence measures on coastal processes
Answer
Coastal defence measures include sea walls, groynes, and beach nourishment, which are designed to protect coastal areas from erosion and flooding.
Identification of Impact
One significant impact is the interruption of natural sediment transport processes. For instance, the construction of groynes can trap sand on one side and lead to erosion on the other.
Examination of the Impact
This can change local ecosystems as habitats are lost due to altered tidal patterns. Over time, if sediment supply is significantly disrupted, the area may experience more severe erosion, leading to potential loss of land and increased costs for maintenance.
Diagram
A labelled diagram depicting the impact of groynes on beach erosion would enhance understanding.
Step 3
The impact of human activities on mass movement processes
Answer
Human activities such as deforestation, construction, and mining can significantly trigger mass movement processes.
Identification of Impact
For instance, landslides can be more prevalent in areas where vegetation has been removed, as plant roots help to stabilize the soil.
Examination of the Impact
Increased runoff due to urbanization leads to greater soil saturation, triggering landslides. Furthermore, construction activities can destabilize slopes, increasing the risk of mass movement. The socio-economic costs of mitigating these risks are substantial, often leading to loss of property and life.
Diagram
A labelled diagram illustrating the before and after effects of deforestation on slope stability would provide a visual reference for this discussion.