Ubaye (river)

Geography

The Ubaye (in Occitan Ubaia ) is a torrential river which takes its source with the Col of Longet to 2655 m of altitude in the small lake of the same name and finishes its race after approximately 83 km in one of the arms of the lake of Greenhouse-Ponçon, where it joined the Durance there. It gives its name to the Vallée of Ubaye. Its principal affluent is the Ubayette, which takes its source with the lake of Lauzanier.

Hydrology

The interannual medium flow or module of Ubaye was calculated during one 47 years period to Lauzet-Ubaye (1960-2007). It is assembled to 20,6 m ³ a second for a surface of basin of 946 km ², that is to say the entirety of the basin.

The river present of the seasonal fluctuations of flow typical of a nival mode, with high waters of spring-be due especially to the snow melt and carrying the average monthly flow on the level from 50,3 to 54,3 m ³ from May to June included (with an in June maximum) and finishing in July (26,4 m ³), followed by a fast fall leading to a short low water level of end of summer (12,8 m ³ in August and September). In autumn the flows go up under the effect of autumnal precipitations in the form of rain (18,1 m ³ and 16,2 m ³ respectively in October and November). This second top is followed from one long period of low waters of winter, from December to March included, involving a fall of the monthly medium flow until a minimum of 7,2 m ³ in February.

With the low water levels, the VCN3 can fall until 3,6 m ³, in the event of dry period quinquennial, which remains consistent. The VCN3 is the past minimal quantity or minimal flow over three days consecutive.

As for the risings, they can be very important following the example almost all alpine rivers. Indeed, the QIX 2 or calculated flow of rising biennial and the QIX 5 or flow calculated for a quinquennial rising is worth respectively 150 and 210 m ³ a second. The QIX 10 or calculated flow of decennial rising is worth 250 m ³, the QIX 20 is worth 290 of them, while the QIX 50 is assembled to 340 m ³ a second. (see note).

The maximum instantaneous flow recorded in Lauzet-Ubaye was of 380 m ³ a second on November 1st, 1963, while the maximum daily output was assembled to 274 m ³ on November 16th of the same year.

The Lame of water past in the catchment area of the river is of 688 millimetres annually, which is raised and results from abundant precipitations on the whole of the surface of its basin. The specific flow (Qsp) is assembled thus at 21,8 liters a second and per square kilometer of basin.

Activities of running water sports

Not comprising any stopping to its mouth, it is an ideal river for the practice of the sports of running water like the Rafting or the Kayak.
With 50 rapids and 9 courses, it is completely possible to discover this river in an original way in full safety, if one is tested. In the contrary case, the presence of a person or a tested monitor is often necessary.

Ubaye is a river of 1st category. The running water sports are authorized:

- 10:00 with 18:00 from March 1st to September 30th except saturdays, Sunday and Monday of the opening of fishings and Friday, Saturday and Sunday of the closing of fishing (

- rising with the sunset the remainder of the year. (source: gendarmerie of the Lauzet-Ubaye)

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