Magdalena is a department of Colombia, located to the north of the country by the Caribbean Sea. Its capital is Santa Marta, named after the Magdalena River. It inherited the name of one of the original nine states of the United States of Colombia that its current territory integrated.
The territory of the Department of Magdalena is formed by four drainage basins which are very different in composition and importance.
The drainage basin of the Sierra Nevada’s western slope is located in the northern part of the department. The Sierra Nevada de Santa Marta creates different rivers that run mainly through the municipality of Santa Marta, and that finally end up draining into the Caribbean Sea.
The rivers that form part of this basin are:
This basin gathers its waters from the rivers coming from the southern and western slopes of the Sierra Nevada. The basin irrigates great extensions of the municipalities of Ciénaga, Zona Bananera, Fundación, Aracataca, and El Retén, which are the heart of the agricultural and livestock economy of the department. The rivers that form part of this basin are:
It also includes a small number of arroyos that only flow during the rainy seasons.
This basin also encompasses the Ciénaga Grande de Santa Marta, the largest marsh in the north of the country which is formed by 16 smaller marshes that are connected by means of arms within the marsh. The balance of the marsh is a delicate one that depends on the fresh waters coming from the Sierra Nevada, and the periodical floodings of the Magdalena River, and the salt water coming from the mouth of the marsh to the sea, that is carried by the current and winds into the marshland.
The Magdalena River Basin is the largest drainage basin in the department, it is formed by the Magdalena River and its tributaries that feed on to the river and the Marsh.
This basin includes the Mompós Depression, which runs from the Zapatosa Marsh to the delta of the Magdalena River. This depression collects the most water in the department, as it is where the Cauca River, Cesar River, and San Jorge River drain their waters. The Magdalena River is by far the most afluyent river of these, and during the rainy season when it overflows, it causes the other rivers to flow backwards, not before overflowing the marshes and sometimes flooding some valleys.
The Ariguaní River drains into the Magdalena River through the Zapatosa Marsh and washes over the central valleys of the departments of Magdalena and Cesar that are the principal areas of agriculture and husbandry in the Caribbean Region.
The department of Magdalena is characterized by its many marshes and extensive marshland valleys. The whole western side of the department its dotted with marshes and lakes due to the Magdalena River that borders the department on this side. Most of this marshes are located in the northwestern side. The permanent marshes are Chilloa, La Rinconada, Tesca, Pijiño, Juan Criollo, Jaraba, Playa Afuera, Grande de Santa Marta, and Zapatosa.
The Ciénaga Grande de Santa Marta is the biggest and by far the most important marsh in the department of Magdalena and one of the most important marshes in the country. It is located in the northwest of the department and is separated from the sea by a very thin margin of land, only a few meters away. It has an extension of 4,280 km2, of which 730 km2 are just water mirrors with a depth of 2 to 6 meters.
The Zapatosa Marsh, located in the municipality of El Plato in the southernmost part of the department, is shared with the Department of Cesar, who controls most of its waters. It has an extension of 310 km2 and at its deepest it reaches about 8m. In it many rivers of different importance merge. The Zapatosa Marsh drains into the Magdalena River by an arm of about 16km of length.
The Department of Magdalena, because of its terrain and proximity to the sea, has unstable weather. Its climate is mainly dictated by its global positioning, and because the department of Magdalena is located on the Intertropical Convergence Zone, it possesses an inter-tropical climate. Temperature in the department is affected by maritime currents, precipitation and atmospheric pressure. It mainly has a hot temperatures with high humidity, but temperatures vary as altitude increases.
The altitude of the department goes from 0m to 5,775m above sea level. The drastic changes of altitude divide the territory into thermal floors. There are no solid or determined divides between these floors as local factors can affect the temperature. The first 200m of altitude are considered the warm lands, they occupy a great extension of the departmental territory, the average temperature is of 30°C. The main urban centers are located in the warm lands, including all of the downtown urban area of Santa Marta. The altitude increases because of the Sierra Nevada de Santa Marta, an isolated mountain, the highest at sea level, and temperatures rise as it goes up.
The presence of the Sierra Nevada in this area of the country has consequences in the climate of the department. The SNSM stands windward blocking the path of the trade winds that blow from the north and northeast, creating a greater cloud accumulation and precipitation. The winds that crash into the mountain ascend in an orographic lift; this cooler air cannot hold the moisture as well as warm air and this effectively raises the relative humidity, creating clouds and frequently precipitation. The clouds that manage to pass over the mountain then move hastily downwards, creating Föhn winds that raise the temperature of the area west of the Sierra, which include the Santa Marta and Ciénaga.
In the coastal area, droughts are caused by the diversion of the cold and warm katabatic winds coming down the Sierra. However, the sea breezes help to cool down temperatures a bit, but by because of their direction, they end up extending the drought effects farther inland.
The department of Magdalena, due to its location in the Intertropical Convergence Zone, has only two seasons. The rainy season takes place between April and November, with a period of less intensity between June and August. The dry season takes place during December and March.
The Mompox Depression presents its own climatic conditions due to its many permanent bodies of water, like the different ciénagas or mashes, and rivers and lakes. This wet habitat, permanently exposed to solar radiation, makes for a very humid environment, with an average annual rainfall of between 1,500 to 2,000mm. These rains are convection rains as they are created by evaporation of its waters by high temperatures; this is typical precipitation around the equatorial belt.
Due to its complicated geography, the precipitation in the department ranges from 250mm in the driest areas, to 4,000mm in the cold floors of the Sierra Nevada.
The Department of Magdalena is located on the north coast of the Colombian Caribbean Region.
On the north it borders the Caribbean Sea. On the northeast it borders the Department of La Guajira, being divided by the Palomino River. On the east it borders with the Department of Cesar, which is in part divided by the Guaraní River.
On the west, it is divided by the Magdalena River, and it borders the departments of Atlantico in the northwest, and Bolívar in the west and southwest.