Physical Geography
Peru is situated in the western part of South America. On the north it
is bordered by Ecuador and Colombia, on the east by Brazil and Bolivia,
and on the south by Chile. The entire west side of Peru is bordered by
the Pacific Ocean. Peru's size is 1,285,215 sq. km (496,095 sq. miles).
To compare: that is roughly France, Italy and Sweden together. Or
theUS-states of Texas, New York, California and Maine together.
Click image to see a detailed map of Peru
Geographic regions
Geographically the country is divided into three main parts:
- La Costa, the long, narrow
coastal region, facing the Pacific
- La Sierra, the mountainousAndes
region
- La Selva, the rainforest region
of the Amazon basin.
Computer-generated overview of Peru. Click
the image to see a bigger version
La Costa, the coastal area, is
semi-arid to arid. It stretches the Pacific coastline from north to
south. Most parts,except for the entire north, consist of desert,and rainfall is very low in this
area. However, many rivers from the Andesflow through the region
towards the Pacific, thus creating fertile rivervalleys. The capital Lima is situated inthe coastal area.
La Costa: Mangrove forest in Tumbes,
the most northern part of Peru
La Costa: Extreme contrast between desert and fertile river-valley in
Arequipa. Image © Angus McIntyre
Parallel and east of La Costa is La Sierra,
the central region which is part of the Cordillera de los Andes. The
Andes range is a vast mountain area covering not only Peru but also
parts of Bolivia, Chile, Ecuador and Argentina, with sub-chains going
as far as Colombiain the north and Tierra del Fuego in the entire south
of the continent.
La Sierra: Andes peaks. Image © Guillaume Dargaud
Peru's Andes is divided in various cordilleras, mountain
ranges. The most important range is the Cordillera Occidental which, in
its way, is divided into other chains with towering mountains, like the
Cordillera Blanca, the
Cordillera Huayhuashand
the Cordillera Raura. The other main mountain chains are the
CordilleraOriental and Cordillera Central. La Sierra covers about 30%
of Peru. Severalof the world's highest mountains can be found here,
like the Nevado Huascaran (6768 m) and the Yerupaja (6634 m). A big
part of Peru's south eastern highland region, around Lake Titicaca, consists of large
plains, called puna or altiplano.
La Sierra: the altiplano. Image © Rien Bouw
Due to tectonic instability, there are some active volcanoes in the
southern Peruvian Andes, like El Misti (5,822 m) near the city Arequipa. Peru is situated at the
point where the Pacific tectonic plate (Nazca plate) and the South
American platecollide. At the collision point, the Andes was created.
East of La Sierra is La Selva, the tropical
rainforest region of the Amazon basin. The densely forested eastern
slopes of the Andes are considered part of La Selva as well, and are
called montaña or cloudforest.
In the northeast the sierra goes downwards into a vast tropical plain,
dominated by the rivers Ucayali and Marañon. The Amazon river
begins at the point where thesetwo rivers flow together.
La Selva: montaña landscape in the Río Mayo valley, San
Martín
Rivers and lakes
There are three drainage systems in Peru. The first one is formed by
about 50 rivers flowing westwards from the Andes into the coastal plain
and the Pacific. The second is formed by the rivers flowing mostly
eastwards from the Andes or the montaña into the Amazon basin. The third
drainage system is Lake Titicaca,
the highest navigable lake in the world at 3,812 m above sea level.
Lake Titicaca drainsinto Lake Poopó in central Bolivia through
the Desaguadero river.
La Selva: Near the Río Tigre
One of the main sources of the Amazon river is the Rio Marañon,
which flows from Peru's central Andes northwards through La Sierra, and
later eastwards into the Amazon basin. Another important river, the
Ucayali, flows from south to north through the montaña, and
joins the Marañon in the northeast of Peru, thus forming the
Amazon river. The Urubamba river, a third important source of the
Amazon, flows from Peru's southern Andes northwards through the
montaña where it joins the Ucayali. The riversTigre and Pastaza
rise in Ecuador and move in southeastern direction intothe
Marañon. The river Napo also rises in Ecuador and flows
directlyinto the Amazon, in the northeast of Peru. The river Madre de
Dios risesin Peru's southern Andes and flows eastwards into Brazil,
where it joinsthe Madeira (which eventually joins the Amazon in Brazil).
Climate
Peru is entirely situated in the tropics, but it has so many different
climate zones, that it can vary from tropical to arctic. LaCosta is
arid, and very moderate, with an average of about 20°C (68°F)
throughout the year. The moderate climate is caused by the Humboldt
Current, a cold wind blowing from the South-Pacific. The coast receives
less than 50 mm precipation each year. The reason for that is that the
Andes receives practically all the rain that comes with the trade winds
of the eastern Amazon basin. That turns the coast into one of the
driest deserts of the world. Thanks to mist-laden clouds that come with
the Humboldt Current, there is still enough moisture for some desert
vegetation to survive. These misty clouds are known as garua,
and are one of the reasons forthe moderate coastal climate. During
winter (May to October) the averagetemperature in Lima won't be much
more than 18°C, while in summer,when the garua disappears, it will
be a pleasant 25°C and sunny mostof the time.
La Costa: Road construction work (due to
El Niño) in the southern coastal desert
More inland, a few hundred metres above sealevel one will rise above
the garua and the weather will be sunny all year round. Most parts ofLa
Costa have a pleasant climate in summer, especially the northern city Trujillo. This city is called La
Capital de la Eterna Primavera (capital of the eternal spring), but
here too, the winter temperature will be moderate because of the garua.
In the most northern part of La Costa, there is no garua at all,and
around Piura and Tumbes the climate is arid and very hot during
summerand winter.
La Costa and La Sierra: satellite image of the area around
Paracas National Park (the
islands and the peninsula on top)
and Ica (centre-left, in the river
valley). You can clearly
distinguish the Pacific coastline, the desert with many sand
dunes and the foothills of the Sierra.
In the Andes range, La Sierra, there is a dry season from May to
September. Daytime temperatures are moderate, but it can be very
coldduring the nights. While the season may be dry, it is still winter
inthat part of the world. Sometimes it may freeze at night in a city
like Cuzco, at 3326 m above sealevel,
althoughin the nearby Sacred Valley,
whichis situated a little lower, you may see occasional palm trees.
Precipation is average in most of La Sierra, with about 800 mm rainfall
during the year. Temperatures vary from very cold in winter (-5°C)
to moderate (21°C) in summer. Apart from the rain season the
weather is usually sunny.
La Selva: Tropical rainforest in Manu
National Park
La Selva, the Amazon region and the montaña, is extremely wet.
In some districts the annual rainfall exceeds 3,500 mm. La Selvahas a
lot of rain during the wet season (November to April). The climateis
humid and of course extremely hot.
See Peru's actual temperature charts,
updated every hour
El Niño
Every few years, the weather in Peru is heavily influenced by El
Niño, a warm current from the central Pacific. El Niño
has a worldwide impact, and changes the entire climate, from Brazil to
Australia, from Africa to Canada. El Niño is concentrated along
the coast of Peru and Ecuador. It is the strongest climatical
phenomenon onearth. El Niño appeared again in 1998 as one of the
most severe ever,causing floodings over Peru's deserts and extreme
draught over Australia and Southeast Asia. In the northern desert
district of Piura, a lake was born as
a result of the immenserainfall. This lake was even bigger than Lago
Junín, Peru's secondlargest lake, but of course it was only
temporary. El Niño means littlechild, and is named after the
Christmas Child, as it appears usually aroundChristmas time.
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