The Guadalquivir

The Guadalquivir is one of the longest rivers in Spain. It starts in the mountains of Jaén and flows west for 657 kilometres. It passes through Córdoba and Seville and Huelva. Finally, it flows through the Gulf of Cádiz into the Atlantic Ocean. 

The river's name has changed many times. The Romans called it Baetis. The current name, Guadalquivir, comes from the Arabic Wadi Al Kabir, which means 'great river'. 

After the discovery of America, ships carried goods from the New World to Seville along the river. Today, ships still travel up the river to Seville. 

The Guadalquivir river basin flows through Doñana National Park where there are lots of different plants and wild animals. Half of Europe's plant species live in this river basin.

Characteristics of rivers

The course of a river is the route of the river from its source to its mouth. 

At the mouth, the river can form an estuary or a delta. 

• An estuary is where fresh water from the river mixes with seawater from the sea. 
• A delta is where materials carried by the river are deposited at the mouth. This forms a triangular-shaped piece of land.
• The flow is the amount of water a river carries. 
• The flow regime is the variation in the flow of a river throughout the year. A river has a regular flow regime when it carries a similar amount of water all year round. A river has an irregular flow regime when it carries a lot of water at some times of the year and not much water at other times. 

Influence of relief and climate

• Relief affects the length of rivers. Rivers are short when they rise in mountains near the sea. Rivers are long when they rise a long way from the sea which they flow into. River water flows faster when the land is very steep. 

The watersheds of Spain

The map is divided into three colours. Each colour represents a different watershed. A watershed is an area where all the rivers and streams flow into the same sea. 

The rivers which flow directly into the sea, for example the Ebro, are the main rivers. Rivers which flow into other rivers are called tributaries. 

There are three watersheds in Spain. The Atlantic watershed is in the west. The Cantabrian watershed is in the north. The Mediterranean watershed is in the east and south. 

The Cantabrian watershed

The Cantabrian watershed is the smallest in Spain, but its rivers carry a lot of water. 

ts rivers are short and very steep, because they start in the Cantabrian Mountains, close to the sea. This area has an Oceanic climate with abundant rainfall. For this reason, the rivers have regular, abundant flow regimes.  

The main rivers in the Cantabrian watershed are:

• The Deba, the Nervión and the Bidasoa in the Basque Country.
• The Saja and the Besaya in Cantabria.
• The Nalón and the Navia in Asturias.
• The Eo separates Asturias from Galicia.

The Mediterranean watershed

In the Mediterranean watershed, the majority of rivers are short. They do not carry much water because they flow through areas with a Mediterranean climate with low rainfall. They have an irregular flow regime, with less water, or drought, in the summer. The flow increases in the spring and autumn. In the wetter months, these rivers sometimes flood. 

The longest rivers in this watershed are:

• The Ebro, which starts in the Cantabrian Mountains. It is a long river with a very abundant flow, because it receives water from many tributaries. Some of these rivers start in the Pyrenees and others start in the Iberian Mountain Chain.  
• The Júcar, which starts in the Iberian Mountain Chain.
• The Segura, which starts in the Subbetic Range.

The Atlantic watershed

The Atlantic watershed is the largest. Its rivers are usually long, because they start in mountains a long way from the Atlantic Ocean. There are three main groups:

• The rivers of Galicia. This area has abundant rainfall.  For this reason, the rivers have regular flow regimes. The Miño is the longest river in Galicia. 
• The rivers of the Inner Plateau. These are long rivers because they start in mountains a long way from the sea. They are dry in summer, but they have abundant flows in spring and autumn. The main rivers are:

- The Duero, and its tributaries the Pisuerga and the Tormes.

- The Tajo, and its tributaries the Jarama and the Tiétar.

- The Guadiana, and its tributaries the Cigüela and the Zújar.

• The rivers of Andalusia. With the exception of the Guadalquivir and its tributary the Gentil, Andalusian rivers are short and have irregular flow regimes. 

In the Canary Islands there are gullies, which are dry when it does not rain.

Lakes and lagoons

Lakes and lagoons are natural bodies of still water surrounded by land. In Spain, they are mostly small. 

Depending on their location, they can be:

• Mountain lakes. Most of these lakes are glacial lakes, formed by melted ice. 
• Lakes on the plains. Many of these lakes are formed by the accumulation of rainwater. 
• Coastal lagoons. These are shallow lakes in coastal areas. They can be of salt water or fresh water. 

Reservoirs

Reservoirs are man-made lakes. They are built to store water from rivers. Water from reservoirs can be used to irrigate fields, to produce energy, or for human consumption. Spain has more than 1,200 reservoirs.