The Rhine

Physical Geography

As one of Europe’s major fluvial system the Rhine flows for a length of 1,230 km from its sources of Vorderrhein and Hiterrhein in Switzerland through liechtenstein, Austria, Germany, France and finally the Netherlands to its mouth where it drains into the North Sea. The catchment area of the Rhine covers 185,000 km², which is much smaller relative to the other major river systems of the world however the Rhine goes through many changes along the course in both regional climatic settings and also the geomorphological setting that is seen for the Rhine. The Rhine itself is significantly shorter than it would be if it was to follow its natural course, this is as a result of anthropogenic interference within the basin with the canalisation of the river since the 19th century.  As such below the overall setting of the Rhine will be analysed to develop an understanding of the physical setting of this fluvial system.

Formation/Geology

The Rhine’s waters originate from glacial melt within the swiss alps with the river splitting and branching into many streams that rejoin the main course of the Rhine as it moves across continental Europe. This section of the Rhine is known as the Alpine Rhine, flowing through the glacial Rhine Valley, as it flows through the Alps the course of the Rhine has been altered from its natural river bed diverting the flow of the water to Lake Constance. 

At the mouth of the Rhine as it discharges into Lake Constance an inland delta is formed as a result of the deposition of material generated along the initial stretch of the Rhine. At Lake Constance the Inland delta is bound by modern canal sections in the East and the Old Rhine in the West. Lake Constance is situated at the border of Germany, Austria and Switzerland within the Alps, the Lake discharges the waters that form the High Rhine westward flowing over the Rhine Falls where the river is joined by a major tributary the Aare. At this point the Rhine continues to flow westward acting as the rough border between Germany and Switzerland before beginning to flow into the Upper Rhine. The High Rhine is a stretch of river that has been heavily modified as a result of anthropogenic actions damming this section of the Rhine, however, within the few remaining natural sections of the river the presence of rapids can still be found.

As the river flows into the Upper Rhine the river begins to flow Northward following a major bend in the river known as the Rhine Knee where it travels along the Upper Rhine section of the river. This section of the river has become heavily modified as a result of the 19th century river straightening program increasing the flow rate in the region while reducing the groundwater recharge as well as reducing the risk of flooding throughout this stretch of the river. As the river continues to flow into Germany we enter the Middle Rhine, which flows through the Rhine Gorge in the Rhenish Slate Mountains. Along this section of the river there is a drop of 27 m from 77.4m above sea level to 50.4 m. 

The Rhine continues to flow throughout Germany entering the North German Plain, at this point the Rhine enters the lower Rhine section where there is another significant drop in elevation from 50 m to 12 m. Similarly to the Upper Rhine this section of river previously had a natural geomorphology with a meandering river course, however, this changed with anthropogenic actions implementing a solid river bed that prevents this movement from occurring. This section of the river has greatly industrialised with the cities of Cologne, Dusseldorf and Duisburg being situated along the banks of the Rhine. Following Duisburg, the industrialised nature of the Lower Rhine gives way to agricultural land as the river flows. 

As the Rhine flows through the Netherlands it is joined by the rivers Meuse and Scheldt helping to form the final section of the river, an extensive deltaic system known as the Rhine-Meuse-Scheldt Delta, which is 25,347 km2 and is the largest delta in Europe. The Rhine continues to flow northward until it reaches the Netherlands where the course changes to a westward direction entering the country in the town of Spijk. At this point the Rhine splits into three distinctive distributaries: the Waal, Nederrijn meaning Nether Rhine and the Ijssel. At this point the course of the Rhine gets convoluted with two thirds of the Rhines water volume flowing westward through the Waal before merging with the Meuse, following a section of river that is both natural and canalised, where the water is discharged into the North sea via the Haringvliet Estuaries. The remaining third of the total volume of water from the Rhine through the Pannerdens canal before entering both the Nederrijn and the Ijssel. Of the remaining third of the water from the Rhine, a third (1/9 of the total Rhine volume) of this volume flows along the course of the Ijssel northward to Ijsselmeer, while the Nederrijn takes the remaining two thirds (2/9 of the total Rhine volume) of the river westward along a course of the river that is parallel to the Waal. However, the Nederrijn then changes its name to the Lek in central Netherlands continuing to flow further west joining the Noord and then Nieuwe Maas at Kinderdijk, a village in southern Netherlands, before the river enters the North Sea.

The Rhine-Meuse-Scheldt Delta (RMS delta) is an extremely important natural region within the Netherlands beginning near Millingen aan de Rijn, near the Dutch-German border with the division of the Rhine into the previously mentioned distributaries. The Delta itself has been heavily modified with the many engineering feats that have taken place across the Netherlands to maintain itself in the face of an ever changing environment. The RMS delta itself is shaped as a result of both the sediment supply and the tidal currents located in this region, however, the deltaic region of the Netherlands was susceptible to major land loss with changes in climate and tidal patterns across the region as such anthropogenic actions were taken to maintain the current setting of the delta. The anthropogenic actions can be seen with the Delta Works, an engineering project throughout the 20th century that protected a large area of the RMS delta through the use of Dams, Locks, Dykes, Levees and even Storm-surge barriers reducing the impact of climatic and tidal changes on the delta, protecting the region from drastic environmental change.

Climate

As the Rhine flows across a large range spanning from the Alps northwards to the Netherlands the climate within the basin changes greatly. The upper region of the Rhine is classified as having a Semi-Continental climate, typified by the seasonality of the weather, with summer temperatures exceeding 35°C while the average annual temperature is 11°C with an annual precipitation in the region is 934 mm. While in the lower course of the river the annual precipitation ranges between 700 and 800 mm with an average temperature of 5-14.4°C as the region is categorised as having a Temperate Oceanic climate with a warm temperate humid climate.

Present Setting

Urbanisation

As a result of the economic development of the European countries within the catchment of the Rhine over the past few centuries, large areas of land have been urbanised with the growth of many cities along the banks of the Rhine. As a result of this urbanisation there have been major changes to the natural function of the river as well as large scale engineering efforts along the course of the river since the 20th century. Therefore, it can be seen that only remaining natural sections of the Rhine are located in the High and Upper Rhine where the anthropogenic influence is kept to a minimum.

Pollution

The pollution of the Rhine has for a long time been one of the largest sources of environmental harm across the basin with increased concentration of extremely toxic materials such as mercury within the waters of the Rhine meaning that it was declared ecologically dead in the early 20th century. Until the early 1980s the major source of water pollution originated from industrial activity, with this industry being located throughout the river’s course but mainly situated in the Lower Rhine as the river passes the major cities of Cologne, Düsseldorf and Duisburg. As pollution impacts the life of flora and fauna across the basin as well as sources of water for those who live within the catchment this has been a key area of concern that has been addressed using a catchment wide method of management. With the implementation of a basin wide approach the key vectors for pollution entering the Rhine were addressed in an effort to improve the environmental quality of the Rhine and allow for the return of species of both flora and fauna that have been lost since industrialisation started within the catchment. This can be seen with the application of the Rhine Action Programme approach that is seen in the catchment that aims to return the river to a more natural state than that which has been seen in the previous centuries. Due to improved efforts across the basin with the implementation of stricter environmental regulations, a transition away from heavy industry and the remediation of the most affected areas such as brownfield sites through the use of reforestation. As a result of the efforts to reduce pollution within the basin we have seen the return of species such as Atlantic salmon and species of waterfowl that had been previously declared as extinct within the basin itself. 

Climate Change

Climate change is one of the main areas of concern for the Rhine basin as a whole, with the effects being seen across the whole basin. Projected increasing temperatures and changes in precipitation patterns in the upper basin are of major concern to maintain the flow of the Rhines sources and tributaries, which would impact the overall flow of the Rhine itself. While in the lower basin along the Rhine Delta the key concern is sea-level rise, as such in order to combat the effects of the increasing sea level extensive engineering activity has taken place across the Netherlands. With the implementation of dams, dykes, levees and locks through the Delta Works project improving the resilience of the Delta to deal with a changing climate, as the engineering feats across the country have protected the extremely low-lying region of the RMS Delta, as well as the majority of the Netherlands from being inundated by the sea.