It is common knowledge that rivers usually flow away from their source, and towards a destination. However, there are some special cases where the opposite is true – the Mississippi River is one such case. The Mississippi River has an interesting history, as some of its sections have been known to flow in both directions. This has spurred endless debates about the underlying causes and effects of this phenomenon. To help clarify the issue and understand better the dynamics of river flow, let us take a closer look.
History of the Mississippi River Flow
The Mississippi River starts at Itasca Lake in Minnesota, where it slowly begins its journey south to the Gulf of Mexico. Along its route, it has famously been known to reverse the direction of its flow and travel upstream in a process known as “backwater flooding”. This phenomenon was first observed in 1937 and is linked to added pressure from heavy rains at the northern sections of the river. The deltaic lands created by the Mississippi River, due to sediment deposition, make it susceptible to backwater flooding in certain sections. This is usually observed during the high-rain seasons in the region.
Causes and Effects of Upstream Flow
The exact cause of upstream flow of the Mississippi River is known as “the wall effect”. This is simply the pressure caused by heavy downpours on the river’s upstream regions. This added pressure causes the river to exceed its banks and diverge from its usual path. Given the position of the lower portion of the Mississippi River Delta and its elevation, the reversed flow is able to reach the Gulf of Mexico. This explains why the phenomenon can be seen during the high-rain seasons in the region and why the pressure from higher levels of precipitation is necessary for the upstream flow condition to persist.
Upstream flow of the Mississippi River has several direct effects on its surrounding areas. The most notable one is the increased flooding risk it poses to residents living nearby. In addition, the phenomenon can cause further damage to public infrastructure, including waterways and roads. While upstream flow can sometimes benefit the Deltaic lands by depositing sediment, too much pressure can cause the river to cut a different path, leading to erosion. Furthermore, while some species of animals may benefit from this change in water direction, others do not – some migratory species may not be able to adjust to this altered route.
Role of Climate Change and Human Intervention
In recent years, the Mississippi River and its flow have been affected by climate change. Heavy downpours, due to higher temperatures, have been known to cause increased pressure on the river resulting in the reversing of its direction. Experts suggest that unless the global average temperature rises are limited, the phenomenon is likely to increase in the near future – likely causing more flooding issues in the region.
While humans have no control over natural events, they can still contribute to changing the course of the Mississippi River. The strongest example of this is the Waynesboro Dam, constructed in 1968 to regulate the flow of the river and reduce the flooding risks. By engineering the river and promoting an artificial stagnation of water, humans can reduce the capacity of the river and generally control its flow rate.
Conclusion
In conclusion, the Mississippi River is a unique example of a river with some sections known to flow in the direction opposite of their source, towards the Gulf of Mexico. This phenomenon, known as backwater flooding, is caused by a combination of heavy downpours, the positioning of the lower section of the Delta, and the role of human intervention in controlling the flow rate of the river. While its effects can be beneficial in some cases, the upstream flow also poses a risk of further flooding to the region. In light of the current situation, it is important that humans limit their global warming contributions and direct their attention towards mitigating the flood risks.
