The Rhine River Basin Urs Uehlinger Karl M. Wantzen Rob S.E.W. Leuven Department of Aquatic Ecology, Swiss Limnological Institute, University of Department of Environmental Science, Federal Institute of Aquatic Science and Konstanz, ATIG-Aquatic-Terrestrial Institute for Water and Wetland Research Technology (Eawag), CH-8600 Dubendorf,€ Interaction Group, D-78457 Konstanz, (IWWR), Faculty of Science, Radboud Switzerland Germany University Nijmegen, NL-6500 GL Nijmegen, The Netherlands Hartmut Arndt Institute for Zoology, University of Cologne, D-50931 Koln,€ Germany 6.8.3. Main 6.1. Introduction 6.8.4. Moselle 6.1.1. Historical Perspective Acknowledgements 6.2. Biogeographic Setting References 6.3. Palaeogeography 6.4. Physiography, Climate and Land Use 6.4.1. Geological Structure and Relief 6.4.2. Climate 6.1. INTRODUCTION 6.4.3. Land Use 6.5. Geomorphology, Hydrology and Nine countries are in part or entirely situated within the Biogeochemistry Rhine catchment, namely Austria, Belgium, France, Ger- 2 6.5.1. Geomorphology of the Main Corridor many, Italy (only 51 km ), Liechtenstein, Luxemburg, The 6.5.2. Hydrology and Temperature Netherlands and Switzerland. With a total length of about 2 6.5.3. Biogeochemistry 1250 km, a drainage area of 185 260 km and an average 3 6.6. Aquatic and Riparian Biodiversity discharge of about 2300 m /s, the Rhine ranks 9th among 6.6.1. Habitat Structure and Riparian Zone Eurasian rivers. The Rhine is the primary artery of one of the 6.6.2. Benthic Algae most important economic regions of Europe (annual gross 6.6.3. Macrophytes and Bryophytes domestic product of 1750 billion US$). The human popu- 6.6.4. Plankton lation of the basin equals 58 million, many of them 6.6.5. Benthic Invertebrates crowded in large urban areas extending along the river be- 6.6.6. Fish tween Rotterdam and Basel. The Rhine provides services for 6.6.7. Amphibia and Reptiles transportation, power generation, industrial production, ur- 6.6.8. Avifauna ban sanitation, drinking water for 25 million people, agricul- 6.6.9. Mammals ture and tourism, and is a classic example of a ‘multipurpose’ 6.7. Management and Conservation waterway (Cioc 2002). The Rhine has greatly influenced the 6.7.1. Economic Aspects history, culture, and economy of Europe over the last 2000 6.7.2. Floods and Flood Defense years. On the other hand, its ecological integrity and biodi- 6.7.3. Conservation and River Rehabilitation versity have been severely affected by human activities, 6.7.4. EU Water Framework Directive particularly in the last 200 years (Friedrich & Muller€ 1984). 6.8. The Major Rhine Tributaries In this chapter, we first give a general overview of the 6.8.1. Aare Rhine basin and subsequently portray different aspects of the 6.8.2. Neckar six morphologically distinct river sections (Figure 6.1a, b, Table 6.1)(Lauterborn 1916) that developed during the genesis of the river. These are: (1) The Alpine Rhine these they built their huts, living like sailors when the water (Alpenrhein) and its tributaries, that is, the reach between covers their environment and like shipwrecked when the the Rhine source (Lake Toma) and Lake Constance, (2) the water has gone’ (Huisman et al. 1998). High Rhine (Hochrhein) that flows from lower Lake Con- With the conquest of Gaul, the Rhine between the sea and stance to Basel, there merging with the Aare, a paramount Neuwied (Middle Rhine) became part of the northern frontier tributary of the Rhine with respect to discharge, (3) the Upper of the Roman Empire (12–9 BC). The Romans fortified the Rhine (Oberrhein), flowing through the rift valley of the border (Limes) from Neuwied in a southeast direction to the Rhine Graben that extends from Basel to Bingen with the Danube at Regensburg, thereby extending the empire across Neckar and Main Rivers as major tributaries, (4) the Middle the right bank. The Roman legacy includes many cities along Rhine (Mittelrhein), flowing through a narrow valley deeply the Rhine such as Chur (Curia) on the Alpine Rhine, Basel incised in the Rhenish Slate Mountains and picking up (Basilea), Mainz (Mogontiacum), Koblenz (Castellum apud waters of the Mosel River at Koblenz, (5) the Lower Rhine Confluentes), Cologne (Claudia Ara Agrippinensium) and (Niederrhein), extending from Bonn to Lobith with Ruhr, Nijmegen (Ulpia Noviomagus Batavorum). In the 3rd century Emscher and Lippe Rivers as major tributaries and (6) the AD, Germanic tribes increasingly invaded the area on the left Delta Rhine, where the discharge is divided in three major bank, which was finally abandoned about 260 AD, and the branches called Nederrijn–Lek, Waal and IJssel. Rhine then became the empire border between Lake Con- stance and the North Sea. Roman rule in the Rhine basin 6.1.1. Historical Perspective ended about 400 AD with the invasion of Germanic tribes. After 500 AD, the Rhine was part of the Kingdom of the Early evidence of human presence in the Rhine catchment Franks and with the coronation of Charlemagne (800 AD) it comprises the jaw bone of Homo heidelbergensis (400 000– became the central axis of the Holy Roman Empire. In the 700 000 years BP) and bones of Homo neanderthalensis following centuries, the empire became increasingly frag- (42 000 years BP). About 35 000 years ago, modern man mented into numerous duchies, ecclesiastical and knightly (Homo sapiens) spread out across Europe. The tracks left by states, each pursuing their own policy with growing success. hunters in the last Ice Age and early postglacial include tools, In 1581, the seven northern provinces of The Netherlands hunting gear and prey leftovers, which have been found at declared independence from Spain. At the end of the Thirty numerous sites within the Rhine basin. As a consequence of Years’ War (1618–1648), The Netherlands and the Swiss postglacial warming, tundra that originally extended be- Confederation, territories that included the Delta Rhine tween the ice shields of Scandinavia and the Alps was in- and Rhine headwaters, left the Holy Roman Empire. The vaded by trees; about 7000 BP vast forest covered Europe expansion policy of Louis XIV, king of France, ended with between the Atlantic coast and western Russia (Kuster€ the annexation of Alsace (1681) by which the Upper Rhine 1999). The loss of hunting grounds limited the size of the became the border river between the Kingdom of France and human population, except for the Neolithic culture that the Holy Roman Empire. adopted agriculture from the Middle East to central and During the French Revolution and subsequent Napoleo- western Europe (6000–7000 years BP). nic wars, the Rhine came completely under the influence of After 800 BC, western and central Europe and the Alps France. In 1806, the Holy Roman Empire was dissolved and were settled by the Celts, presumably originating from late the number of independent territorial units drastically re- Bronze Age cultures. Their heritage includes numerous ar- duced. The remaining duchies, principalities, and kingdoms chaeological artefacts such as weapons, fineries, tombs, for- joined together as the Confederation of the Rhine (except for tresses, and the names of streams and rivers. The name of the Austria, Prussia, Holstein and Pomerania). France annexed Rhine is of Celtic origin (Renos), which means flowing the west bank of the Rhine, which became the northeast water. The Rhine becomes part of written human history border of France between Basel and the Napoleonic King- with the arrival of the Romans. Caesar crossed and bridged dom of The Netherlands, which was annexed by France in the Rhine in 55 and 53 BC, and also gave a first description of 1810. Although the Congress of Vienna (1815) redrew the the Rhine in his commentaries on the Gallic War ‘The Rhine political map of Europe, changes within the area right of the rises in the land of the Lepontii, who inhabit the Alps. In a Rhine were small except for Prussia gaining major territories long swift course, it flows through the territories of Nantu- along the Lower and Middle Rhine that included Rhineland ates, Helvetii, Sequani, Mediomatrices, Triboci and Treveri’. and Westfalia. After the Franco-German War (1870–1871), On its approach to the Ocean it divides into several streams, the unified German Empire annexed Alsace and Lorraine forming many large islands, and then through many mouths and the Rhine became entirely German between Basel and it flows into the Ocean (cited in Cioc 2002). Plinius wrote Lobith. At the end of World War I (1918), both territories about the dwelling places in the delta as ‘There throws the returned to France. The administration of Alsace and Lor- Ocean itself, two times a day, daily and nightly, in a tremen- raine by the Government in Berlin during World War II was a dous stream over a wide country, so one is in doubt if the short episode. Today, all countries in the Rhine basin are ground belongs to the land or to the sea. There is living a members of the European Community except for Switzer- miserable people on the highest known level of the tide and at land and Principality of Liechtenstein. FIGURE 6.1 Digital elevation model (upper panel) and drainage network (lower panel) of the Rhine River Basin. 4 TABLE 6.1 General characterization of the Rhine River Basin Alpine High Upper Middle Lower Delta Aare Neckar Main Moselle Rhine Rhine Rhine Rhine Rhine Rhine (High (Upper (Upper (Middle Rhine) Rhine) Rhine) Rhine) Mean catchment elevation (m) 1764 902 348 336 202 12 1067 432 345 342 Catchment area (km2) 6155 30 148 62 967 41 810 18 836 25 347