The different drought phases observed during the 1970 - 2010 period have u nderlined important weaknesses of West African agricultural systems. The droughts resulted in important decreases in crop production, triggering a significant deficit in food availability. Many studies have identified changes in rain events seasonal patterns as the key drivers of agricultural production failure during these drought phases. In this study, seven agriculturally-relevant intra-seasonal rainfall characteristics ( i.e. , annual rainfall amount, onset and cessation of the rainy season, dry spells, extreme rain events, hot spells, and strong winds) and associated constraints to crop growth are described for the main cereals (maize, millet, and sorghum) in southwestern Burkina Faso. These characteristics are calculated or determined using daily climate data from a local network of 16 weather stations spanning the 1970 - 2013 period. A computation of the intensity and the occurrence of these phenomena during the rainy seasons helped to draw the rainy seasons’ nomenclature. Findings suggest that the rainy seasons during the drought phases are characterized by low annual rainfall amount, late onset, early cessation and more frequent long dry spells (>7 days). Furthermore, the long dry spells mostly occurred during the most sensitive phases of crop development: germination at the beginning of the rainy season and flowering at the end of the rainy season. Also, the intensity and the probability of occurrence of the other extreme events (hot spells and strong winds) during rainy seasons are very high in the establishment phase. Thus, adaptation strategies to mitigate these unfavorable climate conditions include a selection of short-cycle crop varieties combined with supplementary irrigation systems during long dry spells.
Ali, A. and Lebel, T. (2009) The Sahelian Standardized Rainfall Index Revisited. International Journal of Climatology, 29, 1705-1714. https://doi.org/10.1002/joc.1832
Knippertz, P. and Fink, A.H. (2009) Prediction of Dry-Season Precipitation in Tropical West Africa and Its Relation to Forcing from the Extratropics. Weather and Forecasting, 24, 1064-1084. https://doi.org/10.1175/2009WAF2222221.1
Cook, K.H. (2008) Climate Science: The Mysteries of Sahel Droughts. Nature Geoscience, 1, 647-648. https://doi.org/10.1038/ngeo320
Dai, A., Lamb, P.J., Trenberth, K.E., Hulme, M., Jones, P.D. and Xie, P. (2004) The Recent Sahel Drought Is Real. International Journal of Climatology, 24, 1323-1331. https://doi.org/10.1002/joc.1083
Mortimore, M. (1989) Adapting to Drought: Farmers, Famines, and Desertification in West Africa. Cambridge University Press, Cambridge. https://doi.org/10.1017/CBO9780511720772
Wakatsuki, T. and Masunaga, T. (2005) Ecological Engineering for Sustainable Food Production and the Restoration of Degraded Watersheds in Tropics of Low PH Soils: Focus on West Africa. Soil Science and Plant Nutrition, 51, 629-636. https://doi.org/10.1111/j.1747-0765.2005.tb00079.x
Wallace, J.S. (2000) Increasing Agricultural Water Use Efficiency to Meet Future Food Production. Agriculture, Ecosystems & Environment, 82, 105-119. https://doi.org/10.1016/S0167-8809(00)00220-6
Adger, W.N., Huq, S., Brown, K., Conway, D. and Hulme, M. (2003) Adaptation to Climate Change in the Developing World. Progress in Development Studies, 3, 179-195. https://doi.org/10.1191/1464993403ps060oa
Adiku, S., Dayananda, P., Rose, C. and Dowuona, G. (1997) An Analysis of the Within-Season Rainfall Characteristics and Simulation of the Daily Rainfall in Two Savanna Zones in Ghana. Agricultural and Forest Meteorology, 86, 51-62. https://doi.org/10.1016/S0168-1923(96)02414-8
Alo, C.A. and Wang, G. (2010) Role of Dynamic Vegetation in Regional Climate Predictions over Western Africa. Climate Dynamics, 35, 907-922. https://doi.org/10.1007/s00382-010-0744-z
Mertz, O., Mbow, C., Reenberg, A. and Diouf, A. (2009) Farmers’ Perceptions of Climate Change and Agricultural Adaptation Strategies in Rural Sahel. Environmental Management, 43, 804-816. https://doi.org/10.1007/s00267-008-9197-0
Barbe, L. Le and Lebel, T. (1997) Rainfall Climatology of the HAPEX-Sahel Region during the Years 1950-1990. Journal of Hydrology, 188-189, 43-73. https://doi.org/10.1016/S0022-1694(96)03154-x
Ibrahim, B., Karambiri, H., Polcher, J., Yacouba, H. and Ribstein, P. (2014) Changes in Rainfall Regime over Burkina Faso under the Climate Change Conditions Simulated By 5 Regional Climate Models. Climate Dynamics, 42, 1363-1381. https://doi.org/10.1007/s00382-013-1837-2
Nicholson, S.E. (1989) African Drought: Characteristics, Causal Theories and Global Teleconnections. In: Berger, A., Dickinson, R.E. and Kidson, J.W., Eds., Understanding Climate Change, Vol. 52, American Geophysical Union, Washington DC, 79-100. https://doi.org/10.1029/GM052p0079
Olaniran, O. and Sumner, G. (1989) A Study of Climatic Variability in Nigeria Based on the Onset, Retreat, and Length of the Rainy Season. International Journal of Climatology, 9, 253-269. https://doi.org/10.1002/joc.3370090304
Sivakumar, M. (1988) Predicting Rainy Season Potential from the Onset of Rains in Southern Sahelian and Sudanian Climatic Zones of West Africa. Agricultural and Forest Meteorology, 42, 295-305. https://doi.org/10.1016/0168-1923(88)90039-1
Sivakumar, M.V.K. (1992) Empirical Analysis of Dry Spells for Agricultural Applications in West Africa. Journal of Climate, 5, 532-539. https://doi.org/10.1175/1520-0442(1992)005 2.0.CO;2
Sultan, B., Baron, C., Dingkuhn, M., Sarr, B. and Janicot, S. (2005) Agricultural Impacts of Large-Scale Variability of the West African Monsoon. Agricultural and Forest Meteorology, 128, 93-110. https://doi.org/10.1016/j.agrformet.2004.08.005
Waongo, M., Laux, P. and Kunstmann, H. (2015) Adaptation to Climate Change: The Impacts of Optimized Planting Dates on Attainable Maize Yields under Rainfed Conditions in Burkina Faso. Agricultural and Forest Meteorology, 205, 23-39. https://doi.org/10.1016/j.agrformet.2015.02.006
Lebel, T., Taupin, J.D. and D’Amato, N. (1997) Rainfall Monitoring during HAPEX-Sahel, 1. General Rainfall Conditions and Climatology. Journal of Hydrology, 188-189, 74-96. https://doi.org/10.1016/S0022-1694(96)03155-1
Barron, J., Rockstrom, J., Gichuki, F. and Hatibu, N. (2003) Dry Spell Analysis and Maize Yields for Two Semi-Arid Locations in East Africa. Agricultural and Forest Meteorology, 117, 23-37. https://doi.org/10.1016/S0168-1923(03)00037-6
Cleugh, H.A., Miller, J.M. and Böhm, M. (1998) Direct Mechanical Effects of Wind on Crops. Agroforestry Systems, 41, 85-112. https://doi.org/10.1023/A:1006067721039
Lobell, D.B., Burke, M.B., Tebaldi, C., Mastrandrea, M.D., Falcon, W.P. and Naylor, R.L. (2008) Prioritizing Climate Change Adaptation Needs for Food Security in 2030. Science, 319, 607-610. https://doi.org/10.1126/science.1152339
Dai, A. (2011) Drought under Global Warming: A Review. WIREs Climate Change, 2, 45-65. https://doi.org/10.1002/wcc.81
Hulme, M. (1994) Regional Climate Change Scenarios Based on IPCC Emissions Projections with Some Illustrations for Africa. Area, 26, 33-44.
Porkka, M., Wang-Erlandsson, L., Destouni, G., Ekman, A.M.L., Rockström, J. and Gordon, L.J. (2021) Is Wetter Better? Exploring Agriculturally-Relevant Rainfall Characteristics over Four Decades in the Sahel. Environmental Research Letters, 16, Article ID: 035002. https://doi.org/10.1088/1748-9326/abdd57
Bichet, A. and Diedhiou, A. (2018) West African Sahel Has Become Wetter during the Last 30 Years, But Dry Spells Are Shorter and More Frequent. Climate Research, 75, 155-162. https://doi.org/10.3354/cr01515
Salack, S., Klein, C., Giannini, A., Sarr, B., Worou, O.N., Belko, N., et al. (2016) Global Warming Induced Hybrid Rainy Seasons in the Sahel. Environmental Research Letters, 11, Article ID: 104008. https://doi.org/10.1088/1748-9326/11/10/104008
Mensah, C., Amekudzi, L.K., Klutse, N.A.B., Aryee, J.N.A. and Asare, K. (2016) Comparison of Rainy Season Onset, Cessation and Duration for Ghana from RegCM4 and GMet Datasets. Atmospheric and Climate Sciences, 6, 300-309. https://doi.org/10.4236/acs.2016.62025
Fonta, W.M., Sanfo, S., Ibrahim, B. and Barry, B. (2015) Farmers Awareness, Perception of Climate Hazards and Their Willingness to Participate in Crop Insurance Schemes in Southwestern Burkina Faso. Procedia Environmental Sciences, 29, 7-8. https://doi.org/10.1016/j.proenv.2015.07.127
Mahé, G. and Paturel, J.E. (2009) 1896-2006 Sahelian Annual Rainfall Variability and Runoff Increase of Sahelian Rivers. Comptes Rendus Geosciences, 341, 538-546. https://doi.org/10.1016/j.crte.2009.05.002
Arguez, A. and Vose, R.S. (2011) The Definition of the Standard WMO Climate Normal: The Key to Deriving Alternative Climate Normals. Bulletin of the American Meteorological Society, 92, 699-704. https://doi.org/10.1175/2010BAMS2955.1
Yue, S., Pilon, P. and Cavadias, G. (2002) Power of the Mann-Kendall and Spearman’s Rho Tests for Detecting Monotonic Trends in Hydrological Series. Journal of Hydrology, 259, 254-271. https://doi.org/10.1016/S0022-1694(01)00594-7
Ibrahim, B., Polcher, J., Karambiri, H. and Rockel, B. (2012) Characterization of the Rainy Season in Burkina Faso and It’s Representation by Regional Climate Models. Climate Dynamics, 39, 1287-1302. https://doi.org/10.1007/s00382-011-1276-x
Balme, M., Galle, S. and Lebel, T. (2005) Démarrage De La Saison Des Pluies Au Sahel: Variabilité Aux échelles Hydrologique Et Agronomique, Analysée à Partir Des Données EPSAT-Niger. Sécheresse, 16, 15-22.
d’Amato, N. and Lebel, T. (1998) on the Characteristics of the Rainfall Events in the Sahel with a View to the Analysis of Climatic Variability. International Journal of Climatology, 18, 955-974. https://doi.org/10.1002/(SICI)1097-0088(199807)18:9 3.0.CO;2-6
Gourdji, S.M., Sibley, A.M. and Lobell, D.B. (2013) Global Crop Exposure to Critical High Temperatures in the Reproductive Period: Historical Trends and Future Projections. Environmental Research Letters, 8, Article ID: 024041. https://doi.org/10.1088/1748-9326/8/2/024041
Intergovernmental Panel on Climate Change (2001) Climate Change 2001: The Scientific Basis. Cambridge University Press, Cambridge.
Bell, J.L., Sloan, L.C. and Snyder, M.A. (2004) Regional Changes in Extreme Climatic Events: A Future Climate Scenario. Journal of Climate, 17, 81-87. https://doi.org/10.1175/1520-0442(2004)017 2.0.CO;2
Beniston, M. and Stephenson, D.B. (2004) Extreme Climatic Events and Their Evolution under Changing Climatic Conditions. Global and Planetary Change, 44, 1-9. https://doi.org/10.1016/j.gloplacha.2004.06.001
Stephenson, D.B. (2008) Definition, Diagnosis, and Origin of Extreme Weather and Climate Events. Cambridge University Press, New York.
El Adlouni, S., Bobée, B. and Ouarda, T.B.M.J. (2008) on the Tails of Extreme Event Distributions in Hydrology. Journal of Hydrology, 355, 16-33. https://doi.org/10.1016/j.jhydrol.2008.02.011
Issa Lélé, M. and Lamb, P.J. (2010) Variability of the Intertropical Front (ITF) and Rainfall over the West African Sudan-Sahel Zone. Journal of Climate, 23, 3984-4004. https://doi.org/10.1175/2010JCLI3277.1
Panthou, G., Vischel, T., Lebel, T., Blanchet, J., Quantin, G. and Ali, A. (2012) Extreme Rainfall in West Africa: A Regional Modeling. Water Resources Research, 48, Article ID: W08501. https://doi.org/10.1029/2012WR012052
Barron, J. (2004) Dry Spell Mitigation to Upgrade Semi-Arid Rainfed Agriculture. Department of Systems Ecology, Stockholm University, Stockholm.
Modarres, R. (2010) Regional Dry Spells Frequency Analysis By L-Moment and Multivariate Analysis. Water Resources Management, 24, 2365-2380. https://doi.org/10.1007/s11269-009-9556-5
Arnell, N.W., Lowe, J.A., Challinor, A.J. and Osborn, T.J. (2019) Global and Regional Impacts of Climate Change at Different Levels of Global Temperature Increase. Climatic Change, 155, 377-391. https://doi.org/10.1007/s10584-019-02464-z
Youm, I., Sarr, J., Sall, M., Ndiaye, A. and Kane, M.M. (2005) Analysis of Wind Data and Wind Energy Potential along the Northern Coast of Senegal. Revue des Energies Renouvelables, 8, 95-108. http://www.webreview.dz/spip.php?rubrique1
Dai, A. (2011) Characteristics and Trends in Various Forms of the Palmer Drought Severity Index during 1900-2008. Journal of Geophysical Research, 116, Article ID: D12115. https://doi.org/10.1029/2010JD015541
Adelekan, I.O. (2012) Vulnerability to Wind Hazards in the Traditional City of Ibadan, Nigeria. Environment and Urbanization, 24, 597-617. https://doi.org/10.1177/0956247812454247
Pierre, C., Bergametti, G., Marticorena, B., Toure, A.A., Rajot, J.L. and Kergoat, L. (2014) Modeling Wind Erosion Flux and Its Seasonality from a Cultivated Sahelian Surface: A Case Study in Niger. CATENA, 122, 61-71. https://doi.org/10.1016/j.catena.2014.06.006
Sturrock, J.W. (1981) Wind Constraints to Agricultural Productivity. Weather and Climate, 1, 31-35. https://doi.org/10.2307/44280044