Human Interaction With reference to an example you have studied, describe and account for one way in which humans attempt to influence or control natural processes - Leaving Cert Geography - Question B - 2010

The example chosen is the Thames River in London, where various flood control measures have been implemented.

The natural process being controlled in this scenario is the fluvial process of flooding, which occurs during periods of heavy rainfall or snowmelt.

Flood control measures along the Thames include the construction of levees, flood walls, and storm surge barriers.

1. Levees act as a barrier to contain the floodwaters, which can help protect urban areas. However, they can also induce higher water levels upstream, potentially causing additional flooding problems.

2. Flood walls are similar to levees but are often constructed in urban areas to allow for land use adjacent to the river while providing protection from floods.

3. Storm surge barriers, such as the Thames Barrier, are essential to mitigate the impact of tidal flooding; they allow the river to flow normally while closing during storm surges. These engineering solutions demonstrate how human intervention aims to control natural processes.

While these interventions can effectively prevent flooding, they can also alter the natural flow of the river, impacting the river's ecosystem and sediment transport. This shows the dual nature of human influence: while protecting communities, engineering measures can potentially lead to new environmental challenges.