Belle (Nizonne)

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Belle
The Belle at Vieux-Mareuil

The Belle at Vieux-Mareuil

Data
Water code FR :  P7210500
location France , Nouvelle-Aquitaine region
River system Dordogne
Drain over Nizonne  → Dronne  → Isle  → Dordogne  → Gironde  → Atlantic Ocean
source in the municipality of Monsec
45 ° 25 ′ 39 ″  N , 0 ° 33 ′ 36 ″  E
Source height approx.  165  m
muzzle on the municipal boundary of La Rochebeaucourt-et-Argentine and Combiers in the Nizonne Coordinates: 45 ° 29 ′ 6 ″  N , 0 ° 25 ′ 18 ″  E 45 ° 29 ′ 6 ″  N , 0 ° 25 ′ 18 ″  E
Mouth height 97  m
Height difference approx. 68 m
Bottom slope approx. 4.3 ‰
length 16 km
Catchment area 40 km²
Drain at the Mareuil gauge (Dordogne) MQ
 0.317dep1
Right tributaries Ruisseau de l'Étang Rompu

The Belle is a small river in France that runs in the north-western Dordogne department in the Nouvelle-Aquitaine region . It rises in the municipality of Monsec , in the Périgord-Limousin Regional Nature Park, and after 16 kilometers it flows into the Nizonne as a left tributary on the municipal boundary of La Rochebeaucourt-et-Argentine and Combiers . Their average gradient is 4.36 m / km.

Flow through communities

In the Dordogne department:

In the Charente department:

course

The Belle rises 2 kilometers east-northeast of Monsec near the hamlet of Pontarnaud at an altitude of around 165 meters. Until shortly before Monsec it flows in a south-westerly direction, but then turns on a north-westerly course. Its valley widens and it then passes Vieux-Mareuil, Mareuil and Sainte-Croix-de-Mareuil to finally merge south of Combiers as a left branch in the Nizonne coming from the east. The mouth is 97 meters high. At its last hundred meters, the Belle is the border river to the Charente department (border between La Rochebeaucourt and Combiers). The largest right tributary is the 5.1 kilometer long Ruisseau de l'Étang Rompu , which flows into the Belle at Vieux-Mareuil. The left side arms of the Belle are mostly designed as dry valleys (the exception is a small left side arm near Sainte-Croix-de-Mareuil).

geology

The source area of ​​the Belle lies directly below the tertiary ( Eocene ?) Alluvium of the ridge northwest of Saint-Crépin-de-Richemont . However, the Belle rises in a late Pleistocene colluvium , which emerged from the sands of the Santonium in the vicinity . Two kilometers east of Monsec it crosses a fault zone accompanying the Mareuil anticline and then runs into fossil limestone of the Coniacium . After crossing a side branch of the same fault zone, it changes to Rudist limestone of the Turonian . Its further course in a north-westerly direction then more or less follows the axis of the Mareuil anticline, whereby the river has gradually cut into deeper layers; so it flows in Vieux-Mareuil through the tuberous limestone of the Ligérien (Unterturon), in Mareuil through the Cenomanium and finally at Vieux-Mareuil it touches the core of the anticline, consisting of Kimmeridgium . Down the valley from Vieux-Mareuil, the Belle crosses the fault zone of the Mareuil anticline again. The estuary south of Combiers forms an approximately 500 meter wide flood plain, which is filled with Holocene deposits from the Belle and the Nizonne.

geomorphology

The Belletal is a very good example of relief reversal , ie the river has cut above the structural bulge of the Mareuil anticline and created a depression in the terrain. The course of the river is clearly based on the given geological structures (anticline, faults).

Hydrology

The Belle has an average flow rate of 0.317 m 3 / s, measured in Mareuil. The highest measured daily discharge rate so far was 5.99 m 3 / s ( spring flood , measured in Mareuil on April 27, 1986).

ecology

Between Mareuil and the estuary, the valley of the Belle is designated as a type 1 ecotope (French ZNIEFF , zone naturelle d'interêt écologique, faunistique et floristique ). Flora worth protecting thrives in the swamps , moors and wet meadows of the valley.

Landmarks on the river

Castle of Mareuil

Individual evidence

  1. ↑ a b geoportail.fr (1: 16,000)
  2. ↑ a b The information on the river length is based on the information about the Belle at SANDRE (French), accessed on December 24, 2010, rounded to full kilometers.
  3. ↑ a b hydro.eaufrance.fr (station: P8215010 , option: Synthèse )
  4. ↑ INPN ZNIEFF 720008183 - Vallée de la Belle

literature

  • Floc'h, J.-P. et al .: Feuille Nontron . In: Carte géologique de la France at 1/50 000 . BRGM.