Lannemezan (; Gascon Occitan Lanamesa, "heath of the middle") is a commune in the Hautes-Pyrénées department and the Occitanie region in south-western France. The inhabitants are called Lannemezanais.
Lannemezan is the largest city in the .
Geography
The Petite Baïse has its source in the commune.
Lannemezan is around east of Tarbes, and around 100 km south-west of Toulouse.
Geology and relief
Over 50 million years, driven by movements of compression, low relief which constitutes the Pre-Pyrenees has risen. Glaciers and streams that cascade down its slopes subject to mountain erosion which flows off from the foot of it. While continuing to rise, the mountain has erected the cluster of its deposits and thus forms the Plateau de Lannemezan, head of a gigantic which puts its mark upon much of the southwest, up the Garonne at more than to the north. High up and submitted to the four winds, the site already assigns itself an identity that would assist in its history and reputation.
The soil is composed of uncultivated and barren land, dotted with woodlands, coppicing, cut of marshes and heath. The terrain is of limestone origin with a topsoil up to deep. Peat moor is exploited near La Barthe-de-Neste. Analysis of the soil in the commune of Lannemezan shows the results presented in the following table.
The plateau rises to over above sea level in the vicinity of Lannemezan. The top of the foothills face the Pyrenean part of the Neste Valley, the river which then turns east at the foot of the plateau. Other rivers (Gers, Baïse, etc.), flow radially from this point to the northwest, north and northeast, and the altitude of the plateau decreases gradually. On the south side, this plateau is still connected to the Pyrenean massif by a narrow tongue of land between Izaux and Avezac. Otherwise, it ends to the southwest and the southeast by a steep overhang and residual hills (Capvern, Mauvezin, etc.) facing the Pyrenees.
Natural vegetation
The natural vegetation of Lannemezan and its small region is characterised by a heathland landscape, although moisture of soils is highly variable depending on their location (particularly in relation to their proximity to water courses).
Thus, in wet areas near the rivers extend many bogs characterised by dwarf gorse (Ulex minor), St. John's wort (Hypericum elodes L.) marshes or wet meadows which extend Medusa's trumpets (Narcissus bulbocodium L.), of oatgrass (Arrhenatherum longifolium) or alder (Alnus).
In drier areas grow more woody species such as Pyrenean oak, also known under the name of tauzin oak (Quercus pyrenaica), as well as pedunculated oak (Quercus robur) or chestnut (Castanea sativa Mill).
In all cases, the soils are rather acidic type with adjustable humidity, which imposes certain constraints for the development of plant species. These development constraints are represented on the adjoining humidity/acidity chart.
Hydrography
Eighteen rivers have their sources on the Plateau de Lannemezan or pass through the territory of the commune. The main are listed in the following table.
Natural risks and disasters
The commune is placed under supervision in relation to some possible natural and technological hazards:
Flood
Industrial risk
Earthquake: Zone of seismicity 1B
Transport of dangerous goods
Recent natural disasters on the commune are as follows, since 1980 (from most recent to oldest):
Location
General location:
Lannemezan is a bastide situated in the centre of the Plateau de Lannemezan between Tarbes and Toulouse on the Petite Baïse. Between the Atlantic and Mediterranean, at the outlet of the valleys of the Pyrenees, Lannemezan imposes itself as a privileged strategic its geographical position city.
Lannemezan is located at the east of the department of the Hautes-Pyrénées, from the border with Haute-Garonne to the east, from the border with Gers in the north and from the border with Spain to the south ().
Bordering communes
Spatially, Lannemezan is wedged between the following nine communes: Campistrous to the northwest, Clarens in the northeast, Capvern to the west, Uglas and Pinas to the east, Avezac-Prat-Lahitte in the southwest, La Barthe-de-Neste and Escala to the south, and Cantaous to the southeast.
Distance to some large French cities
The orientation and location of Lannemezan, compared to some large French cities, is given in the following table (distances are given as the fastest route by road):
Area
The city of Lannemezan has an area of , which is ranked: