@article{fdi:010046335,
  title = {1896-2006 {S}ahelian annual rainfall variability and runoff increase of {S}ahelian {R}ivers},
  author = {{M}ah{\'e}, {G}il and {P}aturel, {J}ean-{E}mmanuel},
  editor = {},
  language = {{ENG}},
  abstract = {{U}pdated rainfall data to 2006 confirm that the {S}ahelian rainfall has increased since the end of the 1990s, but the annual average rainfall is still as low as during the drought of the 1970s. {T}he decrease of rainfall is higher in the {N}orthwest and lower in the {S}outheast {S}ahel. {T}he increase of temperature over {W}est {A}frica during the end of the 20th century induced an increase of {P}otential {E}vaporation, which might reduce the runoff. {H}owever, the joint effect of climate change and of human activities on land cover over more than three decades is responsible for an increase of the runoff coefficients of the {W}est {A}frican {S}ahelian {R}ivers since the 1970s, despite the rainfall shortage during the same period, as revealed by the analysis of runoff from {M}auritania, {B}urkina-{F}aso and {N}iger. {T}he runoff coefficients have increased in regions with less than 750 mm of annual rainfall, under {S}ahelian and subdesertic climates, leading to increased flood peaks, occurring earlier in the season. {E}ven if it is difficult to separate which part of this runoff coefficient increase is due to climate change alone or to human impact on land cover, the highest values are observed in the most inhabited areas, where land cover is dominated by cultivated areas. {T}his climatic/human impact on land cover is so huge that it has changed since decades the hydrological regimes of the {S}ahelian {R}ivers, from the small watershed to the largest one, such as the {N}iger {R}iver at {N}iamey. {T}o cite this article: {G}. {M}ake, {J}.-{E}. {P}aturel, {C}. {R}. {G}eoscience 341 (2009).},
  keywords = {{C}limatic variability ; {R}unoff ; {R}ainfall ; {R}unoff coefficient ; {H}ydrological regime ; {S}ahel ; {A}frica},
  booktitle = {},
  journal = {{C}omptes {R}endus {G}eoscience},
  volume = {341},
  numero = {7},
  pages = {538--546},
  ISSN = {1631-0713},
  year = {2009},
  DOI = {10.1016/j.crte.2009.05.002},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046335},
}