@article{fdi:010074753,
  title = {{E}mpirical and analytical methods to characterize the efficiency of floods to move sediment in a small semi-arid basin},
  author = {{M}egnounif, {A}. and {O}uillon, {S}ylvain},
  editor = {},
  language = {{ENG}},
  abstract = {{O}ver a long multi-year period, flood events can be classified according to their effectiveness in moving sediments. {E}fficiency depends both on the magnitude and frequency with which events occur. {T}he effective (or dominant) discharge is the water discharge which corresponds to the maximum sediment supply. {I}f its calculation is well documented in temperate or humid climates and large basins, it is much more difficult in small and semi-arid basins in which short floods with high sediment supplies occur. {U}sing the example of 31 years of measurements in the {W}adi {S}ebdou (north-west {A}lgeria), this paper compares the two main statistical approaches to calculate the effective discharge (the empirical method based on histograms of sediment supply by discharge classes and an analytical calculation based on a hydrological probability distribution and on a sediment rating curve) to a very simple proxy: the half-load discharge, i.e. the flow rate corresponding to 50% of the cumulative sediment yield. {T}hree types of discharge subdivisions were tested. {I}n the empirical approach, two subdivisions provided effective discharge close to the half-load discharge. {A}nalytical solutions based on log-normal and log-{G}umbel probability distributions were assessed but they highly underestimated the effective discharge, whatever the subdivision used to adjust the flow frequency distribution. {F}urthermore, annual series of maximum discharge and half-load discharge enabled the return period of hydrological years with discharge higher than the effective discharge (around 2 years) to be inferred and showed that more than half of the yearly sediment supply is carried by flows higher than the effective discharge only every 7 hydrological years. {T}his study was the first to adapt the analytical approach in a semi-arid basin and to show the potentiality and limits of each method in a such climate.},
  keywords = {{ALGERIE} ; {ZONE} {SEMIARIDE}},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {22},
  numero = {12},
  pages = {6335--6355},
  ISSN = {1027-5606},
  year = {2018},
  DOI = {10.5194/hess-22-6335-2018},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074753},
}