Ibrahim M., Favreau Guillaume, Scanlon B. R., Seidel J. L., Le Coz M., Demarty Jérome, Cappelaere Bernard. (2014). Long-term increase in diffuse groundwater recharge following expansion of rainfed cultivation in the Sahel, West Africa. Hydrogeology Journal, 22 (6), p. 1293-1305. ISSN 1431-2174.
Titre du document
Long-term increase in diffuse groundwater recharge following expansion of rainfed cultivation in the Sahel, West Africa
Ibrahim M., Favreau Guillaume, Scanlon B. R., Seidel J. L., Le Coz M., Demarty Jérome, Cappelaere Bernard
Source
Hydrogeology Journal, 2014,
22 (6), p. 1293-1305 ISSN 1431-2174
Rapid population growth in sub-Saharan West Africa and related cropland expansion were shown in some places to have increased focused recharge through ponds, raising the water table. To estimate changes in diffuse recharge, the water content and matric potential were monitored during 2009 and 2010, and modeling was performed using the Hydrus-1D code for two field sites in southwest Niger: (1) fallow land and (2) rainfed millet cropland. Monitoring results of the upper 10 m showed increased water content and matric potential to greater depth under rainfed cropland (> 2.5 m) than under fallow land (a parts per thousand currency sign1.0 m). Model simulations indicate that conversion from fallow land to rainfed cropland (1) increases vadose-zone water storage and (2) should increase drainage flux (similar to 25 mm year(-1)) at 10-m depth after a 30-60 year lag. Therefore, observed regional increases in groundwater storage may increasingly result from diffuse recharge, which could compensate, at least in part, groundwater withdrawal due to observed expansion in irrigated surfaces; and hence, contribute to mitigate food crises in the Sahel.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Hydrologie [062]
