| Services |
|
|
|
|
 |
|
| News |
|
|
|
|
|
|
|
|
|
| Channels |
| Home & Family |
|
|
|
|
|
|
|
| Leisure |
|
|
|
|
| Technology |
|
|
|
|
|
| Business |
|
|
|
|
| Science |
|
|
|
|
|
|
|
|
|
|
Site Search  |
|
|
|
|
| Free email |
|
|
|
|
 |
Dynamic bed causes irregular course of river |
| TheallIneed.com/NC&T/NWO |
In view of future large-scale projects, such as river improvement measures in the project 'Ruimte voor de rivier' [Room for the River], the societal relevance of responsible river management is increasing. The large-scale spatial redesigning of the Rhine Branches could result in greater dynamics in the riverbed, which could give rise to more problems for shipping. That might lead to increasing costs for maintenance dredging. Moreover an increase in the riverbed dynamics might also affect the high-water levels. Saskia van Vuren investigated the uncertainty in riverbed dynamics.
Changes in the riverbed elevation can give rise to high-water problems and flooding, drought problems which hinder shipping, problems with respect to the discharge distribution at bifurcation points, and erosion problems. Fluctuations in the groundwater level caused by these so-called morphological changes can exert an influence on the local ecology and agriculture. In her thesis, Van Vuren uses examples to illustrate how insights into the uncertain behaviour of the riverbed can support managers in the design, management and maintenance of the river.
The researcher evaluated the effect of various river improvement measures along the Rhine on the riverbed, such as lowering floodplains, constructing secondary channels, and setting back dikes. Some locations were found to be more sensitive to management measures than others. This comes to light in the average changes, the variability and the seasonal dependency of the shape of the riverbed.
 | | Van Vuren investigated the effect of the riverbed on the water level. The photo shows high water in the River Waal in 2002 between Brakel and Zaltbommel. (Photo: NWO) |
At present, the hydraulic models used by river managers for high-water level predictions often assume a fixed bed elevation. Van Vuren discovered that mid-term variations in the bed elevation and bed activity around bifurcation points influence high-water levels. This being the case the researcher argues that in future, high-water level predictions must take morphological dynamics (how the riverbed changes in response to altered circumstances) into account.
|
| About the Author |
©2005 All rights reserved
|
|
|
| Quotes | If I work incessantly to the last, nature owes me another form of existence when the present one collapses. -- Goethe, 1829
If a few idiots want to risk their necks flying across the country thats fine, but nothing will ever replace trains.
|
| Writers | | If you are a writer and want to see your article published at Theallineed.com, just click here to submit. |
|
Nepal's human rights commission has made great strides, says UN official
The Manager Interview - The 5 Management Skills that Matter