EBRO RIVER: ROUTE, TRIBUTARIES, CHARACTERISTICS, FLORA - GEOGRAPHY - 2024

The Ebro River is located on the Iberian Peninsula and has an approximate length of 930 km with an average flow of 426 m ³ / s, which is why it is recognized as the longest and most powerful river located exclusively in Spanish territory.

Its basin covers 83,093 km ², has a triangular shape and is located on a rift valley formed by the elevation of three mountain systems: to the north the Pyrenees, to the southwest the Iberian system and to the east the Catalan Mountain Range.

Its delta occupies 330 km2, 20% of this territory is protected by the Delta del Ebro Natural Park. Photo: Luis Javier Modino Martinez

This important natural resource has witnessed the history of the peninsula and humanity. Through its waters, various peoples carried out the exploration and occupation of the territory, taking advantage of the fertility of its banks for their subsistence.

The wealth of its basin and its strategic location in the Mediterranean made it a territory coveted by ancient powers such as Carthage and Rome.

The cultural richness of the cities that settled on its banks is the product of occupations and conquests by Celts, Gauls, Romans and Arabs through the years. This mixture provides an extraordinary character to the region, the monuments that survive are considered heritage for humanity and are also an important economic activity for their tourist attraction.

History

Geological origins and first settlements

Geological studies affirm that the Ebro was constituted as a marine basin of the Atlantic 37 million years ago. Tectonic movements and the uplift of the systems that limit its basin separated it from the Atlantic Ocean and turned it into a lake of salt water.

Two phenomena occurred simultaneously: the original lake dried up and the Cardona salt mines were formed. Since then, the trench occupied by the lake began to receive fresh water from the rivers that flow down from the mountains that surround it. Little by little, the pit filled up and between 8 and 12 million years ago it started to overflow and find its way to the Mediterranean Sea.

Since ancient times, the Ebro river has been a cultural and commercial communication channel between the populations that settled on its banks. There are records of Suessetan, Sedetan, Celtiberian, Ilergete, Lacetan and Gauls settlements in pre-Roman times.

Wars and control of the Roman Empire

Between 218 a. C. and 201 a. C. developed the second Punic war between Carthage and Rome, the two powers that dominated the Mediterranean Sea in its western part and disputed control of the Iberian Peninsula. In this framework, the first naval battle took place on the Ebro river, which faced 40 Carthaginian ships against 55 Roman ones.

The Carthaginian contingent was defeated due to a surprise attack by Roman forces. As a consequence they lost resources, the naval dominion of the peninsula and alliances with native tribes that were changed to the Roman side.

Between 29 a. C. and 19 a. The Cantabrian wars took place, clashes between Rome and the Asturian and Cantabrian peoples that inhabited the territory currently occupied by the communities of Asturias, Cantabria, León and Palencia. The Roman Empire that had greater organization and resources definitively surpassed the tribes that faced it and managed to completely occupy the peninsula.

With this victory, a long series of conflicts over the dominion of the territory ended and the period of political and economic stability began, with the integration of the Iberian Peninsula into the Roman Empire that lasted until the 3rd century AD. C.

Visigoths, Arabs and Christians

The dominion of the peninsula passed from the hands of the Romans to those of the Visigoths between the year 416 and the first decade of the 8th century AD. C., when the weakness caused by the struggle between two Visigothic noble families, the plague and the high tax pressure on the population, served the scene for the Muslim invasion of the peninsula.

The south and the center of the peninsula, including the Ebro valley, presented little resistance to the Muslim advance, while to the north the tribes that populated the mountains faced the invaders and founded the Kingdom of Asturias.

The political instability of the basin, plagued by conflicts and alliances, did not see its end until the Modern Age, with the unification through the marriage of the crowns of the medieval kingdoms of Aragon and Castile.

Civil war

Between July and November 1938 the battle of the Ebro river took place, pitting the nationalist faction against the republican faction during the Spanish Civil War. The battle took place between Amposta and Mequinenza, a front of more than 60 km.

The Republicans were forced to retreat across the river to its left bank. With a balance of more than 20,000 casualties between both sides, the defeat of the Republicans in the Ebro was decisive for the definitive loss of the second republic.

Source and mouth

The Ebro river crosses Spain from north to south, located in the east of the country. It is born in the Hijar river, in the Pico Tres Mares at 2,000 meters above sea level, located in the Autonomous Community of Cantabria.

After 20 km from its source, the Hijar river becomes underground for a section of approximately 800 m and resurfaces in Fontibre, a place that until 1987 was erroneously indicated as its source.

After traveling 930 km, it empties into the Mediterranean Sea through its delta located in the province of Tarragona. The accumulation of sediment formed the Island of Buda, which divides the stream into two arms.

Travel

On its way to the sea, the Ebro bathes the territories of the Autonomous Community of Cantabria and from there it passes to Miranda de Ebro in the Autonomous Community of Castilla y León. Then Haro and Logroño plays in the Autonomous Community of La Rioja.

It leaves towards Tudela, located in the Foral Community of Navarra, crosses Zaragoza in the Autonomous Community of Aragon, from there it runs forming its delta towards Tortosa in the province of Tarragona, located in the Autonomous Community of Catalonia.

Its delta occupies 330 km ², being 20% ​​of this territory protected by the Natural Park of the Delta del Ebro. This was created in August 1983 within the framework of the Program on Man and the Biosphere of UNESCO.

Cities it crosses

In its history rich in exploration and conquest events, many peoples settled on its shores and over the centuries large cities were consolidated, among which the following stand out:

Saragossa

Zaragoza is a cosmopolitan city with more than 2,000 years of history. The capital of the Autonomous Community of Aragon has impressive monuments in its streets that speak of its history through Roman, Muslim, Jewish and Christian traces, some of which have been declared a World Heritage Site by Unesco.

The Ebro river crosses the city from west to east for 10 km where pedestrian walks and outdoor activities abound to enjoy nature without leaving the city.

In addition to its cultural appeal, Zaragoza has a wide variety of proposals that adapt to all styles, such as walks around the city, artistic and gastronomic activities, excursions in its surroundings and a nightlife that invites you to enjoy.

Logroño

Logroño is another capital touched by the waters of the Ebro river. Located in the Autonomous Community of La Rioja, it is rich in history and traditions that began in the Middle Ages. It is part of the Camino de Santiago and it owes its rise and much of its cultural wealth to the passage of artists, merchants and pilgrims on their way to Compostela.

The Ebro crosses the city from west to east and on it two bridges are erected that connect its banks, one of them dates from the 11th century, over which the Jacobean route passes at its entrance to the city.

Many of its monuments are related to the Christian pilgrimage, such as the Pilgrims 'Hostel, the Pilgrims' Fountain, the Church of Santiago and the Cathedral of Santa María la Redonda, famous for its representation of Calvary by the Renaissance master Miguel Ángel.

Rioja gastronomy also stands out, thanks to the richness of its orchards, it offers fresh and high quality products in exquisite dishes to the delight of locals and visitors.

Tudela

Tudela is a city located in the Foral Community of Navarra. Founded in 802, this city of Islamic origin is a living sample of the coexistence and cultural miscegenation between Muslims, Jews and Mozarabs.

Its streets combine Gothic, Renaissance, Romanesque and Baroque styles with countless monuments of great historical appeal.

This town invites you to explore it on foot to enjoy its culture in multiple squares and cobbled streets. Its gastronomy is largely nourished by local products grown on the banks of the Ebro.

Tortosa

Tortosa is located in the province of Tarragona, in the Autonomous Community of Catalonia. It has monuments of medieval, Renaissance, Baroque and Modernist architecture, considered as a whole National Monument of Spain.

In addition to its architectural wealth, another attraction of this city is its privileged location between two parks: the Els Ports Natural Park and that of the Ebro Delta, which allows you to fully enjoy the landscapes, the climate and the biodiversity.

There are spaces especially dedicated to the observation of birds that inhabit the protected areas of the parks and multiple routes for exploration, both on foot and by bicycle, throughout the Ebro delta. There are also many water activities in the delta area and on the coast.

Tributaries

The Ebro river receives the waters of the rivers located in the mountains that limit its course. Among the most important are the rivers Oca, Aragón, Tirón, Matarraña, Najerilla, Guadalope, Iregua, Martín, Leza, Gállego, Berries, Cidacos, Huerva, Alhama, Jalón, Queiles, Huecha, Nela, Ega, Jerea, Zadorra and Omelet.

characteristics

This important natural resource is one of the fundamental pillars of the development of the region that bathes with its waters. A communication route par excellence since ancient times and a source of natural benefits has allowed an important agricultural and tourist development in the region.

Floods

Due to the climatic diversity that develops in its basin from 2,000 meters above sea level, it has two important floods: the first occurs in spring between March and May as an effect of the melting of snow in the surrounding mountains, and the second from December to February due to ocean rains from the Atlantic Ocean.

The flood season is generally considered to span a single period from October to May. The dry season occurs from July to October.

Economy

The richness of sediments that the Ebro valley receives is a source of great agricultural and livestock prosperity. The cultivation of vegetables, rice, fruits and olives abounds. The waters of the river have been used since ancient times with the construction of numerous canals and reservoirs to control floods.

The Ebro valley contributes 1/5 of agricultural production and 1/3 of meat production to the Spanish economy thanks to the fundamental advantage of access to water, its storage and distribution; and the availability of quality land for agricultural and forage production.

Manufacturing industry develops to a lesser extent in the area, transforming raw materials from agriculture and livestock into intermediate products and inputs for other industries, finished products for the final consumer.

Another activity of great importance in the region is tourism that is based on the beauty of the landscape, the biodiversity and the cultural and historical wealth of the region.

Around 300,000 people sail through the Ebro in a tourist plan to enjoy the activities that take place around the river and the visual richness that unfolds in the basin. Sport fishermen enjoy the 300 fishing grounds located in the Ebro to forge unforgettable memories.

Dams

Currently there are more than 110 reservoirs that are used for the production of electricity on the Ebro river basin. With 360 power plants installed, the accumulated potential is approximately 4,000 MW that supplies a large percentage of the country's electricity needs, approximately to a fifth of the population.

Contamination

The agricultural, livestock and industrial use of the Ebro valley has contaminated its waters with pesticides, nitrates, nitrites and ammonium used or derived from these activities, causing the deterioration of ecosystems and affecting the quality of the water.

Urban waste also affects the health of the river, mainly due to inadequate treatment of it before its discharge into the riverbed. In 2008, thanks to the application of better and greater controls on the part of the Spanish government, agricultural and livestock practices have been improved, as well as the treatment of urban waters aimed at recovering the ecological status of the river.

Flora

The Ebro River is the one with the greatest diversity in the Iberian Peninsula due to the climatic diversity that develops in its basin from its source to its mouth.

At 2,000 meters above sea level there is vegetation that requires a lot of humidity. Around 200 meters above sea level, the climate becomes dry and its temperature varies from one extreme to another with the seasons, while in the delta the climate is Mediterranean.

On the route of the Ebro river you can find beech, pasture, oak groves, galachos, eucalyptus, water lilies, poplars, willows, black poplars, alders, reeds, groves, cerzo, ash trees, elms, brambles, galachos, wild rose, aguazales and hawthorn to the bar.

Fauna

Along the Ebro river there are more than 200 areas assigned for the protection of habitats and species that seek to maintain the health of the local fauna.

Among the aquatic species that make life in its channel are trout, zander, carp, river wolves, pike, palometas, catfish, eels, sabogas, sturgeons, river pearls and crabs.

Among the birds that can be observed in the Ebro river are the sapper plane, black kite, avocet, marsh harrier, warbler, osprey, cuckoo, bittern, swans, geese, wryneck, woodpecker, wigeon, fly bird, frieze mallard, cranes, mallard, ducks, storks, coot, purple heron, martinete and egret.

The most common mammals in the area are the genet, the otter, the fox, the badger, the wild boar and the weasel.

Monsters of the Ebro

A series of large species have been introduced by humans into the waters of the Ebro river on purpose, while others have been inadvertently introduced. Two species stand out in this group due to their voracity and the impact they produce on native species.

Catfish

Native to rivers in central Europe, the catfish is a voracious predator that can live up to 80 years, during which time it does not stop growing. Its presence in the Ebro river has been recorded since the mid-1970s. It is speculated that it was introduced intentionally for its value as a prey in sport fishing.

Despite being a fish from much colder waters, it has adapted perfectly. The climate and temperature of the Ebro have been beneficial for this invasive species that has grown and multiplied to the point of endangering the native species.

One of its victims was the barbel, an edible fish that was common in the river until the arrival of the catfish, which led to its extinction; although it is still present in other European rivers. In 2015, the press reported the capture of a 6-meter catfish on the banks of the Ebro near Zaragoza.

Zebra mussel

This mollusk can subsist in fresh and brackish water. It is native to the Black, Caspian and Aral Sea, considered one of the most harmful invasive species in the world for native ecosystems.

Its presence in the Ebro river was detected in 2001. Its introduction could have been accidental since this species clings to any surface. Their rapid growth and stubborn resistance put the balance of food chains at risk, crowding out native species by stealing their food. Such is the case of the river pearl, a native species of the Ebro that has endangered the invasion of the zebra mussel.

References

1. Sculpting the Ebro Delta: its past, present and future history, published on March 18, 2019, taken from tiempo.com.
2. Ebro, Great Aragonese Encyclopedia, taken from encyclopedia-aragonesa.com.
3. Magallón Botaya, M. Ángeles, Organization of the Roman road network in the middle valley of the Ebro, taken from ifc.dpz.es.
4. Traces of the Roman Empire in the Ebro Basin, taken from iagua.es.
5. Pina Polo, Francisco, From the indigenous city Salduie-Salduvia to the Roman colony Caesar Augusta, Magazine of Ancient History, number 35, taken from doi.org.