Santiago Map

Geographical location, administrative division and population of the island of Santiago 

Santiago, like all the islands of the Cape Verde archipelago, rises from a submarine platform in the shape of a horseshoe, located at a depth of about 3000 meters, and is part of the base to which the eastern islands belong (B. Bebiano 1932).

Location and description of the island

Santiago island is located in the southern part of the archipelago and belongs to the group of Leeward Islands, together with Maio, Fogo and Brava. It is the largest island of the Cape Verde archipelago, with a land area of ​​991 square kilometers and a circumference of 970 kilometers. Santiago is ovoid in shape and tapers towards the north-south, especially in the northern part of the island.

The highest point of the island is the mountain Pico d'Antónia, which reaches a height of 1,392 meters. Santiago is geographically delimited by the latitudes 15º20' and 14º50' north and the longitudes 23º50' and 23º20' west from the Greenwich meridian.

Measurements and dimensions

The maximum length of the island is 54.9 kilometers from Ponta Moreia in the north to Ponta Mulher Branca in the south. The maximum width is 29 kilometers from Ponta Janela in the west to Ponta Praia Baixo in the east.

Administrative division and population

Administratively, the island of Santiago is divided into nine (9) municipalities and eleven (11) parishes. The island has a population of approximately 290.000. The country's capital, Cidade da Praia, is located on Santiago and is home to a large part of the Cape Verdean population.

Due to its significant geographical location and size, Santiago plays a central role within the Cape Verde Islands in terms of both population and administration. The island forms the administrative and often economic heart of Cape Verde.

Climate of the island of Santiago 

The island of Santiago in Cape Verde is characterized by a tropical dry climate. This ranges from arid to semi-arid and is characterized by two clearly distinguishable seasons.

From December to June is the dry season, also known as the Brisas period. During this time, hot, dry winds blow from the Sahara, the so-called Harmatão winds. These carry a lot of dust, which forms dense clouds and significantly reduces the humidity. These conditions can have various negative effects on people and the environment.

The rainy season, also called the water period, lasts from August to October. It is influenced by the migration of the Intertropical Convergence Zone (ITCZ) and brings some rainfall. The rainy season is also usually the warmest time of the year. The months of July and November are considered transition months, as they can have characteristics of both the dry and rainy seasons.

The average monthly temperature on Santiago is around 25°C and fluctuates only slightly over the course of the year. Although rainfall has been very irregular in recent years, relative humidity remains quite high.

A key factor in the climatic differences on Santiago is altitude. The relief and the orientation of the island to the prevailing winds lead to significant regional climate differences. While the coastal regions are very dry, the higher elevations have a wetter climate with good vegetation cover. The east side of the island in particular receives more rainfall, which is also due to the wind directions.

These diverse climatic conditions significantly shape the landscape and way of life on the island of Santiago.

Elevations, valleys and plains of the island of Santiago 

The island of Santiago is characterized by a very irregular relief, characterized by elevations, valleys and plains. The shape of the island is reminiscent of a pear, tapering towards the north-south, with a clear narrowing in the northern part between Chão Bom and Porto Formoso.

The average altitude of the island is 278.5 meters, while the highest point is on the Pico d'Antónia massif, at 1,392 meters. In the south of the island, a series of terraced areas stands out, extending between sea level and 300-500 meters. In the west, the slope of the Santa Catarina plateau is extremely steep down to the sea.

In the east, the rise begins with steep slopes, with gradually decreasing slopes until reaching the coastal plains. In the north of the island there is the extensive region of Tarrafal, which includes flat plains and whose altitudes vary between 20 and 300 meters. The Chão Bom platform is particularly noteworthy, with altitudes ranging from 0 to 20 metres.

This irregular relief is crossed by a relatively dense hydrological network, often in deep valleys. These valleys extend from the Pico d'Antónia and Serra da Malagueta massifs, which are at altitudes of over 1,000 metres.

Based on altitude, different climate zones and their corresponding rainfall levels can be distinguished on Santiago:

• Arid climate: altitudes below 100 metres with an annual rainfall of less than 250 millimetres.
• Semi-arid climate: altitudes between 100 and 200 metres with 250-400 millimetres of rainfall per year.
• Sub-humid climate: altitudes between 200 and 500 metres with 400-500 millimetres of rainfall per year.
• Humid climate: altitudes above 500 metres with over 500 millimetres of rainfall per year.

These geomorphological and climatic differences have a significant impact on the water availability, vegetation and agricultural viability of the island of Santiago.

The main geomorphological units of the island of Santiago

The island of Santiago in Cape Verde can be divided into seven main geomorphological units according to the description by M.M. Marques (1990). This variety of geographical structures contributes significantly to the unique landscape and the different uses of the island.

The first unit is the Achadas Meridionais, the terraced areas in the southern part of the island. These extend between sea level and altitudes of 300 to 500 meters and offer an interesting topography for agricultural use and settlements.

The Maciço Montanhoso de Pico d'Antónia forms the second main unit and represents the highest elevation system on the island. The summit of Pico d'Antónia reaches a remarkable height of 1,392 meters and significantly influences both the microclimate and the vegetation in its surroundings.

The Planalto de Santa Catarina is located in the western part of the island and is characterized by extremely steep slopes that lead down to the sea. This third main unit is characterised by a dramatic landscape that presents both challenges and opportunities for management.

The Flanco Oriental, the fourth unit, begins with steep slopes and gradually changes to gentler slopes that reach the coastal plains. This area is particularly interesting for its different microclimates created by the changing slope gradients.

The fifth main unit, the Maciço Montanhoso da Malagueta, is located in the northern part of the island and rises to over 1,000 metres. This mountain massif is a central part of the island's water management system, as many rivers and streams originate here.

In the northern area of ​​the island is the sixth unit, Tarrafal. This region comprises flat plains with varying elevations from 20 to 300 metres. Particularly notable is the Chão Bom platform, which has elevations between 0 and 20 metres.

Finally, there is the Flanco Ocidental, the western slope of the Santa Catarina Plateau. This seventh unit is known for its extremely steep slopes that descend to the sea, forming a unique, wild coastal landscape.

These main geomorphological units illustrate the complex structure and geographical diversity of the island of Santiago. They significantly influence the local climate, vegetation and uses, making them essential for understanding and sustainably using the island's natural resources.

Geologische Aspekte der Insel Santiago

Die Insel Santiago besteht fast vollständig aus vulkanischen Gesteinen, hauptsächlich Basalt und verschiedenen vulkanischen Ablagerungen wie Brekzien, Lapilli und Tuffen. Diese geologischen Merkmale sind ausschlaggebend für das Erscheinungsbild und die Struktur der Insel.

Die wichtigsten Gesteinsarten der Insel sind Basalt, der die Insel dominiert, und pyroklastische Ablagerungen, die Brekzien, Lapilli und Tuffe enthalten. In kleinerem Umfang kommen auch fonolithische und trachytische Gesteine vor, die meist in Form von Schloten, Gängen und selten als Decken auftreten. Afanitische, also feinkörnige Gesteine bedecken einen Großteil der Insel, während die gröber strukturierten phaneritischen Gesteine seltener sind.

Die geologische Entwicklung der Insel ist durch verschiedene vulkanische Aktivitäten geprägt. Die älteste Gesteinsformation, der Alte Eruptivkomplex, zeichnet sich durch ein Netz von Gängen aus, das sich über die gesamte Insel erstreckt. Die jüngste Formation ist der Monte das Vacas, der hauptsächlich aus pyroklastischen Materialien besteht und die jüngste vulkanische Aktivität auf Santiago repräsentiert.

Zu Beginn der geologischen Entwicklung der Insel traten basaltische Lavaströme auf. Diese initiale Phase wurde gefolgt von Eruptionen fonolithischer und trachytischer Gesteine, die Schlote und Gänge bildeten. Anschließend kam es zu einer weiteren Phase von Basalt-Eruptionen. In einer späteren Phase, in der einige dieser Basalte unter Wasser standen, wurden kleine Mengen Kalkstein abgelagert.

Diese geologischen Besonderheiten beeinflussen die Landschaft und die Nutzungsmöglichkeiten der Insel Santiago erheblich. Das Verständnis dieser geologischen Strukturen ist essenziell für die nachhaltige Entwicklung und Nutzung der natürlichen Ressourcen der Insel.