People try to control the natural processes at work in the landscape that may cause disasters such as landslides or flooding (as seen in the above photograph) - Leaving Cert Geography - Question Question 1 - 2008

The process being controlled is river flooding, which occurs when rivers overflow their banks due to excessive rainfall or snowmelt.

Levees are embankments built alongside rivers to prevent floodwaters from spilling into surrounding areas. By elevating the riverbanks, levees improve the capacity of rivers to hold water during peak flow periods, reducing the risk of flooding. These structures can be constructed using earth, concrete, or stone and are often reinforced to withstand the pressure exerted by floodwaters. However, while levees provide protection to the immediate area, they can inadvertently increase flooding risk downstream as they confine the flow of water.

1. Effectiveness: Levees can effectively reduce the occurrence of flooding in protected areas during moderate flood events.
2. Economic impact: They allow for the development of agriculture and urban areas in flood-prone regions, driving economic growth in those areas.
3. Long-term challenges: Over-reliance on levees may lead to a false sense of security, resulting in inadequate preparation for major flood events and potentially catastrophic failures if overwhelmed.

An example of levees in action can be found along the Mississippi River in the United States. Here, an extensive system of levees has been constructed to manage flooding, particularly during the spring melt and heavy rainfall periods.