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Fortes crues des petits cours d'eau du Sahel Forme de l'hydrogramme
| Content Provider | Semantic Scholar |
|---|---|
| Author | Ribstein, Pierre Rodier, J. |
| Copyright Year | 1989 |
| Abstract | ABSTUCT PEAK FLOWS FROM SMALL SAHEL BA~INS: HYDROGRAPH FORM In updating a brief study of 1965, the authors, starting form the data fiom 29 representative basins in. the Sahel, developed practical rules for the estim.ation of the peak discharge of the 10 year flood for ungauged basins of less than 12 km’. Surface runoff being com.mon, the methodology uses the unit hydrograph concept, with the detennination of the su.rface runoff volu.me using the runoff coeficient Kr, and the determination. of the peak flood by the estimation of the hydrograph characteristics : the runoff duration. Tb and the peak c0eficien.t 01 (ratio of maximum discharge to the average suface runoff discharge). The studv is divided into two parts : the first deals with the basins for which the 10 year storm corresponds to the unit hydrograph where the hydrograph considered is the instantaneous unit h.ydrograph ; the second part corresponding to th.e most fiequent conditions, deals with smaller basins for which the hydrograph to be considered with the 10 year stonn is a composite hydrograph. For this study the concept of fictitious basins permits the survey of the variations of the hydrograph chara.cteristics in relation to four main factors : area, 10 year storm depth, slope and infiltration. It is noted that the 01 coeficient remains approximately constant. This study pennitted also a sensitivity analysis of the variations of maximum discharge roith th.e main factors. The methodology should be used jointly with table of the infiltration capacit-y of the Upper soi1 layers an.d with a question.naire taking into account the possible extreme values of other runoff factors whose influence on Tb or (Y may be signtjicant. |
| Starting Page | 33 |
| Ending Page | 47 |
| Page Count | 15 |
| File Format | PDF HTM / HTML |
| Volume Number | 4 |
| Alternate Webpage(s) | http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_4/hydrologie_cont/27280.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
