| Titre | Les débits solides du Rhône à proximité de son embouchure : données récentes (1994-1995) / The discharge of suspended sediments near to the mouth of the Rhône recent statistics (1994-1995) | |
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| Auteur | Didier Pont | |
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Revue |
Géocarrefour Titre à cette date : Revue de géographie de Lyon |
| Numéro | volume 72, no 1, 1997 Le Rhône, l'axe et la vallée | |
| Page | 23-33 | |
| Résumé anglais |
A precise estimation of the discharge of suspended sediments of the Rhône, near to its mouth (Arles), was carried out using daily measures between June 1994 and May 1995. This period is characterised by an important average discharge and a flood with a likely recurrence of once every 30 years. A preliminary analysis taking account of the activity of the main tributaries shows two major types of floods : floods originating in the south, due largely to the influence of the Cevennes and the Mediterranean alps, and these originating from the north, fed predominantly by the Saône and/or upper Rhône. The average daily load of suspended material is 123 mg/l I (6to 3612 mg/l). In a year the mass of material transported in suspension is estimated at 13.9 million tonnes for a total water discharge of 69,81 109 m3. In periods of flood (discharge > à 3000 m3/s), representing 78 days of the year (22% of the period), the discharge of suspended sediments equals 11.3 million tonnes, or 81.1% of the total mass of transported material discharge. The flood of november 1994 alone transported 5.2 million tonnes. Examination of paired-values (water discharge - daily flows of suspended material - fig. 6) shows that for a given flow suspended material is transported by floads originating from the north than those from the south. Applying linear regression models to daily discharge values of the Rhône at Beaucaire since 1961 gives an estimated annual discharge of suspended sediments of 6.2 million tonnes. This calculation shows the very considerable variation in such discharges between years, with figures ranging from 1.4 to 16.4 million tonnes. Discussion centers on the role of watershed management, modifications to land use and climatic variability with respect to the mass of suspended material transported by the Rhône. Source : Éditeur (via Persée) |
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| Article en ligne | http://www.persee.fr/web/revues/home/prescript/article/geoca_0035-113x_1997_num_72_1_4675 |
