The
Madriu-Perafita-Claror Valley is a valley of glacial origin
which drains the largest secondary basin in Andorra. It
is a subsidiary of the main basin of the Eastern Valira
and covers a surface area of 4247 hectares. It is defined
by the river Madriu and by its most important tributary,
the Claror i Perafita river, which converges at Entremesaigües.
The river Madriu flows through 11.5 kilometres of land with
an average gradient of 7.6%.
The highly broken relief of this zone is sitting on a substratum
of siliceous rock (granite at Gargantillar-l'Illa and metamorphic
at Port Negre) which has been shaped by the action of glaciers.
The result is a wide diversity of conditions and micro-climates
deriving from the variable altitude (which goes from 1055
to 2905 metres) and orientation (great difference between
the sunny and shaded slopes due to the east-west disposition
of the main valley).
Water
also plays an important role in the valley with the presence
of numerous mountain lakes, rivers and torrents, small waterfalls,
marshy ground and sloughs.
The plant landscape divides up into three stages of vegetation
which change depending on the altitude:
•
Montane stage (1000-1700 metres)
-
with woods of
Scots pine, thickets of
-
deciduous trees
and mowing meadows.
•
Subalpine stage (1700-2200 metres)
-
with
woods of mountain pine and silver
-
fir.
••Alpine
stage (2200-2900 metres)
-
dominated by pasture
land, screes
-
and
outcrops
of rock.
Ownership of land in about 99% of the surface area of the
Madriu-Perafita-Claror Valley is communal. The remainder
(about 1%) is held by almost thirty private owners and covers
little more than 42 hectares of valley bottom land located
in the parish of Escaldes-Engordany.
