Blog 2 - Mann und Erosion (Humans and Erosion)

Much like our own Mississippi, the Rhine remains a commercial highway as it has been for thousands of years. It also must be noted that this part of the river was straightened and dredged in the 19th century for the benefit of that traffic.

The natural evolution of  the Rhine-Main did not stop where we left off in the previous blog, of course, but continues to this day. As we learned in class, the landscape is constantly weathering and eroding, attempting to reach an equilibrium; humans have played a big part in this story for thousands of year, due to the invention of agriculture.

The ending of the Ice Age laid the groundwork for later human settlement. Although the rivers themselves were free of the glaciers, they were filled by the melting glaciers of the south and the Bavarian tablelands and loess, the silty, ground-up dust which the glaciers left in retreat, soon filled the alluvial plans of the subsided valleys and basins through which they flowed. Forests soon followed, filling the river-lands with thick, rich hardwood trees (of which the famous Schwarzwald or Black Forest is a latter day remnant). It is around three thousand years ago that people start to play their part; in clearing these old growth forests for farming, the early farmers unwittingly increased the Rhine's erosion and meandering, along with that sediment rapidly growing the size of the delta on which the modern Netherlands sits today. When the Romans arrived, they found a use for the marshy wetlands too, mining them for peat to be used in heating and salt production.

A monument to Johann Gottfried Tulla, the father of the modern Rhine

It was not until the Middle Ages that major attempts were first made to harness and control the rivers, beginning with Charlemagne's grand attempt to build a canal connecting the Rhine-Main with the Danube in the late 8th century (it is unknown if it was ever completed and only a short stretch remains today). During the 11-13th century in the high-point of the Medieval warm period, the new agricultural developments lead to the need to expand farmland and protect them; draining marshes, damning of minor tributaries, and embanking of major ones like the Main. Already in this period, people tried to stop the meandering and silting of the river via canals and Louis XIV even began to "move" the river in 1685, gaining France 1.5 kilometers of land by 1840. The major change to the nature of the river, however, was the work of Johann Tulla. A student of chemistry and mineralogy and proven field engineer, he was appointed director of the Oberdirektion des Wasser und Straßenbaues (Directorate of Water and Road Construction) in 1817 to plan and carry of the straightening and, I would say, taming of the Upper Rhine. The project was not completed until the 1870's, but it forever changed the river from a winding waterway with ox-bows and branching marshes (not at all dissimilar to the Mississippi) into a faster flowing, embanked one, controlled with dams. Yet, one can still find what the old Rhine looked like in the nature reserves around Mainz and Bingen and in an upcoming blog, we will look at the other efforts being made the preserve the natural aspects of the river system and the surrounding lands.

Sources:
Channel erosion and erosion monitoring along the Rhine River, B. Droge, H. Engel, E. Golz, 1992
http://en.wikipedia.org/wiki/Rhine
http://en.wikipedia.org/wiki/Upper_Rhine
http://en.wikipedia.org/wiki/Johann_Gottfried_Tulla