Chéran
The Chéran is a French river of Préalpes of the North, which runs in the departments of the Savoy and the Haute-Savoie. It is an affluent of the Fier out of left bank, therefore a tributary of a tributary of the the Rhone.
Geography
Chéran takes to its source in the Massif Wallows, in the commune of École, in Savoy. It is thrown in the Fier, after a course of 54 km. It sprinkles in particular Châtelard, Alby-on-Chéran and Rumilly.
The catchment area of Chéran is mainly included in the Regional natural park of the Solid mass of the Wallows.
Hydrology
The flow of Chéran was observed during one 58 years period (1950-2007), with Allèves, locality of the department of the Haute-Savoie located unfortunately at a score of kilometers of its confluence with the Fier. Surface thus studied is of 249 km ², that is to say a little more than 70% of total area catchment river which makes 350 km ².
The interannual medium flow or module of the river with Allèves is of 7,77 m ³ a second.
Chéran presents seasonal fluctuations of flow marked well, like generally in Alpine medium. Its mode is mainly nival, with a rather important rain component. The high waters are characterized by a double top, the first in November - December corresponding to the rains of autumn with an average monthly flow of 8,2 m ³ a second for each of the two months. In January one attends a light fall of the flow (7,89 m ³), a more significant part of precipitations being retained in the mountain, in the form of snow. The second top proceeds in spring, from March to May included (with a maximum very Net in April) and corresponds especially to the snow melt. It is characterized by average monthly flows going from 10,6 to 12,6 m ³ a second. From May, the flow drops quickly, to the low waters (low water level) of summer which take place from July to September included, involving a fall of the average flow monthly to the floor of 3,58 m ³ in August, which remains extremely comfortable it is true. But these monthly averages are only averages and occult more marked fluctuations over short periods or according to the years.
With the low water levels, the VCN3 can fall until 0,560 m ³ a second (560 liters a second), which becomes relatively severe (see note).
The risings, as for them, can be important, as it is of rule in mountainous territory. The QIX 2 and QIX 5 are worth respectively 110 and 140 m ³ a second. The QIX 10 or calculated flow of decennial rising is of 160 m ³ a second, the QIX 20 of 180 m ³, while the QIX 50 is assembled to 210 m ³ a second (see note).
The recorded maximum instantaneous flow with Allèves was of 250 m ³ a second on October 1st, 1960, while the value maximum day laborer was of 148 m ³ a second on February 15th, 1990. If one compares the first of these values on a QIX scale of the river, one notes that this rising largely higher than the volume of raw the cinquantennale was defined by the QIX 50, and thus very exceptional.
Chéran is a very abundant river. The Lame of water past in its area catchment of 987 millimetres annually, which is three times superior with the overall average of France all confused basins, but normal is completely compared with the various rivers of the area of the préalpes of Savoy, generally very abundant. It is moreover more definitely higher than the average of the basin of the the Rhone (557 millimetres with Beaucaire and 670 in Valence). The specific Flow (or Qsp) reached of this fact the very robust figure of 31,2 liters a second and per square kilometer of basin.
Etymology
One most probably finds in the name Chéran the étymon pre-indo-European * because for rock, * carannus > Chéran being a parallel of * caronna > the Garonne in the Pyrenees, with the suffix * - anna, - onna , river.
| Random links: | Reinhold Ewald | Marijuana the Heir to Villandon | Dirty District | Unfasten | Gaahl |