Sunday, April 29, 2012

Final Assessment and Fluvial Landscape


The Victoria Falls region is a Fluvial Landscape. The Zambezi River that supports the Victoria Falls and creates them has a dissolved carrying load. The material is chemically carried in the water. So even though the water appears clear, the sediment and particles are just dissolved. Therefore, unlike suspended load, the flow has a much higher velocity that can “entrain clay and fine silt than coarse sand.” The Kentucky River is a good river in which to compare the Zambezi. The future will reveal more erosion due to the high velocity of the water concerning weathering.

 http://en.wikipedia.org/wiki/File:Zambezi_River_at_junction_of_Namibia,_Zambia,_Zimbabwe_%26_Botswana.jpg

The Zambezi River stream has a Perennial flow regime, which means it flows year round. The key to perennial flow regimes is baseflow. Victoria Falls is a wet region. The types of channels that compile the Zambezi River are meandering channels, which are single channel wiggles across a floodplain. This is predominant in wet areas, such as the Zambezi, with perennial streams. The meandering channel’s elements include point bar, thalweg, and cut bank. This channel is able to handle flooding well.




The process of the meandering channel amplitude increasing is when deposition occurs at the point bars and erosion at cut banks, and the high velocity goes from cut bank to cut bank. The cut bank erodes and the bank collapses. The point bar deposits even as the cut bank moves over time. It then continues until it creates goosenecks. Specific to the Zambezi River according to tothevictoriafalls.com, “The point where the lake overflowed and eroded into its former margins is seen at Katombora, linking the Upper and Middle Zambezi river courses that we know today.”



After 10 Years

Because of the high velocity of the river, the finer particles have an erosive impact on solid rock because of the higher speed. According to tothevictoriafalls.com, the erosion and water level of the stream of water will decrease at a rate of 7 cm per year. Yet, the erosion of Victoria Falls is a very slow process, so there will not be much of a difference between the Falls today and in ten years.

After 100 Years

The Zambezi River flows and erodes upstream, and creates the wide waterfalls, then narrows and forms gorges at the bottom. The weathering in joints in the Zambezi River in the basalt promote weathering within the cracks of both chemical and physical. The Devil’s Cataract, which is the western north-south break-through is suspected to erode away because it is already lower than most of the lines of the Fall. Also, the water level is supposed to decrease by 7 meters every 100 years.


The Devil's Cataract
http://media-3.web.britannica.com/eb-media//36/102136-050-9D0524C3.jpg 


After 1000 Years

The Falls will have decreased by 70 meters. With global climate change, it is suspected that the Victoria Falls will have severely decreased, and may not exist at all within the next 1000-100,000 years.

Conclusion

The Fluvial Landscape of the Victoria Falls regarding weathering, soil type, and weather processes are connected through the formation of the Victoria Falls, and how it maintains itself. The Fluvial aspects and the high velocity of the river support weathering in carrying sediment throughout the wet region, the soil type is a result of the evaporation of the Falls and transformation into precipitation, therefore related to the climate, and the weather processes are also due to the climate in some aspects. The meandering channel may erode to reveal different pathways. Essentially, with global climate change, the falls may not exist in the next 1,000-100,000 years.

Sources

"To The Victoria Falls." Future of the Victoria Falls. Web. 30 Apr. 2012. 

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