Evaluating Bed-material Transport Equations using Field Measurements in a Sandy Gravel-bed Stream, Arbúcies River, NE Spain
✍ Scribed by Batalla, Ramon J.
- Book ID
- 101218679
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 121 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0360-1269
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✦ Synopsis
Bed-material load under a wide range of hydraulic conditions was sampled in a poorly sorted, sandy, gravel-bed river (Arbúcies, NE Spain) during 1991 and 1992. The Arbúcies data showed a marked scatter of bed-material discharges, reflecting the high variability of bedload rates as well as of suspended sediment concentrations. Bed-material discharges were used to test five bedload and bed-material formulae. The degree of agreement between observed and predicted values varies greatly. The percentage of observations in which the discrepancy ratio between observed and computed values has a value between 0•5 and 2, range from 25 per cent (van Rijn), to 38 per cent (Brownlie), 52 per cent (Meyer-Peter and Müller), 65 per cent (Engelund and Hansen), and 68 per cent (Ackers and White). The wide range of hydraulic conditions from which the data were obtained and the poor sorting of the bed sediment affected the performance of the van Rijn (1984) and equations. The degree of correlation between observed transport rates and values predicted by the Engelund and Hansen (1967) formula appears to be unaffected by the poorly sorted bed material of the Arbúcies River. The Meyer-Peter and Müller (1984) model predicted bedload transport in the Arbúcies River with reasonable accuracy and no bias for transport values under low and intermediate flow conditions. The best agreement with measured values was obtained using the Ackers and White (1973) model, a reflection of its original design for poorly sorted sediment.