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Bankfull Discharge Recurrence Interval in Gravel‐bed Rivers
Author(s) -
Petit F.,
Pauquet A.
Publication year - 1997
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/(sici)1096-9837(199707)22:7<685::aid-esp744>3.0.co;2-j
Subject(s) - hydrology (agriculture) , baseflow , geology , streams , pebble , drainage basin , gumbel distribution , interval (graph theory) , structural basin , bed load , geomorphology , streamflow , geotechnical engineering , sediment , extreme value theory , geography , sediment transport , mathematics , computer network , statistics , cartography , computer science , combinatorics
Bankfull discharge was identified in some 30 gravel‐bed rivers representing in total c. 40 gauging stations. The catchment sizes cary from 4km 2 to nearly 2700km 2 . Bankfull discharge value increases with basin size. In the case of gravel‐bed rivers developed on an impermeable substratum, the following equation emerges: Q b =0·087 A 1·044 . Bankfull discharge recurrence interval was determined by fitting maximum annual floods ( T a ) into Gumbel's distribution and then using the partial duration series ( T p ) in this same distribution. Recurrence interval is below 0·7 years ( T p ) for small pebble‐bed rivers developed on an impermeable substratum; it reaches 1·1 to 1·5 years when the catchment size of these rivers exceeds 250km 2 . Rivers incised in the soft schists of the Famenne show larger channel capacity at bankfull stage, a small width/depth ratio and thus higher recurrence intervals (1·4–5·3 years with T a and 1–4·4 years with T p ). Baseflow‐dominated gravel‐bed streams and sandy or silty rivers experience less frequent bankfull discharges, with a recurrence interval higher than 2 or even 3 years ( T p ). © 1997 John Wiley & Sons, Ltd.