Thérain
The Thérain is a French Rivière which takes its source in the Pays of Bray between Saint-Michel-with Halescourt and Grumesnil in Seine-Maritime with 175 meters of altitude. Upstream, the river runs in an outline of depression monoclinale of the Northern reverse of the Pays of Bray, then, after Songeons, follows a Synclinal until its junction with the Oise (Right Bank) downstream from Creil. Its valley, parallel with the Country of Bray, brings moisture and greenery in the arid Picardy plate.
Its medium flow reaches 7,9 m/s with Maysel.
Its valley, benefitting from the proximity of the Paris and its suburbs, is industrialized and populated (Thérain sprinkles in particular Beauvais). It separates the Pays from Thelle in the South, of the Beauvaisis in North.
Affluents
-
Brook of Hardouins
- Tahier
- Brook of Wambez
- the Small Thérain
- the Avelon
- River of Saint-Quentin
- River of Saint-Just
- Liovette
- Wage
- Ru of Berneuil
- Pit of Pride
- Laversines
- Trye
- Sillet
- Ru of Maladrerie
- Ru of Lombardy
- the Sparrow
- Ditch the Bishop
- the Brook of Saint-Claude
- the Wax Brook
- the Brook of Flanders
Its course
In the Seine-Maritime:
In the Oise:
- Canny-on-Thérain ~ Saint-Samson-the-Pottery ~ Héricourt-on-Thérain ~ Fontenay-Torcy ~ Sully ~ Escames ~ Let us think ~ Lachapelle-under-Gerberoy ~ Vrocourt ~ Martincourt ~ Crillon ~ Haucourt ~ Bonnières ~ Milly-on-Thérain ~ Herchies ~ Troissereux ~ Fouquenies ~ Saint-Just-of-Marsh ~ Beauvais ~ Villers-on-Thère ~ Rochy-Cop ~ Montreuil-on-Thérain ~ Bailleul-on-Thérain ~ Villers-Saint-Sepulchre ~ Hermes ~ Heilles ~ Saint-Felix ~ Hondainville ~ Mouy ~ Balagny-on-Thérain ~ Wax-the-Mello ~ Mello ~ Maysel ~ Saint-Vaast-the-Mello ~ Cramoisy ~ Montataire ~ Thiverny mouth.
Hydrology
Following the example few rivers of the west of the basin of the Seine, Thérain is a remarkably regular river. Its flow was observed over one 41 years period (1967-2007), with Maysel, locality of the Département of Oise located a few kilometres from its outlet in Oise. At this place the catchment area of the river is of 1.200 km ².
The interannual medium flow or module of the river with Maysel is of 7,82 m ³ a second.
Thérain present of the seasonal fluctuations of flow far from important, with high waters of winter-spring carrying the average monthly flow on the level from 8,8 to 10,6 m ³ a second, of December with the beginning of May included (with an in January maximum - February), and low waters of summer from July to October, with a light fall of the monthly medium flow going up to 5,4 m ³ in August.
The VCN3 can fall until 2,6 m ³, in the event of dry period quinquennial, which remains very comfortable. Let us recall that the VCN3 is the past minimal quantity or minimal flow over three days consecutive.
The risings are not very important. Thus the recorded maximum instantaneous flow was of 35,5 m ³ a second on March 21st, 2001, while the value maximum day laborer was of 35,6 m ³ a second the same day. The QIX 2 and QIX 5 are worth respectively 17 and 22 m ³ a second. The QIX 10 or calculated flow of decennial rising is of 25 m ³ a second, the QIX 20 of 28 m ³ and the QIX 50 of 32 m ³ (see note). From where it arises that the risings of March 2001 were exceptional.
Thérain is a small but regular and relatively abundant river, well supplied with regular precipitations. The Lame of water past in its catchment area is of 206 millimetres annually, which is moderate, lower than the overall average of France. The specific Débit (or Qsp) is assembled at 6,5 liters a second and per square kilometer of basin.