Déficits hydro pluviométriques et implications sur l'activité agricole en zone Soudano-Sahélienne au Cameroun: Cas de Maroua et Yagoua (1948-2013

(1)

Samuel Aimé Abossolo, Joseph Armathé Amougou

et Mesmin Tchindjang

Perturbations climatiques et pratiques

agricoles dans les zones agroécologiques

du Cameroun

Changements socio-économiques et problématique

d’adap-tation aux bouleversements climatiques

Connaissances et Savoirs

(2)

ĞƚŽƵǀƌĂŐĞĂĠƚĠƌĠĂůŝƐĠƉĂƌůĞƐĠĚŝƚŝŽŶƐ ŽŶŶĂŝƐƐĂŶĐĞƐĞƚ^ĂǀŽŝƌƐ ϭϳϱ͕ďŽƵůĞǀĂƌĚŶĂƚŽůĞ&ƌĂŶĐĞʹϵϯϮϬϬ^ĂŝŶƚͲĞŶŝƐ dĠů͗͘ϬϭϴϰϳϰϭϬϭϬʹ&Ăǆ͗Ϭϭϰϭϲϴϰϱϵϰ ĐŽŶƚĂĐƚΛĐŽŶŶĂŝƐƐĂŶĐĞƐͲƐĂǀŽŝƌƐ͘ĐŽŵ ǁǁǁ͘ĐŽŶŶĂŝƐƐĂŶĐĞƐͲƐĂǀŽŝƌƐ͘ĐŽŵ /ŵƉƌŝŵĠĞŶ&ƌĂŶĐĞ dŽƵƐĚƌŽŝƚƐƌĠƐĞƌǀĠƐƉŽƵƌƚŽƵƐƉĂǇƐ͘ ĠƉƀƚůĠŐĂů͘ ΞĚŝƚŝŽŶƐŽŶŶĂŝƐƐĂŶĐĞƐĞƚ^ĂǀŽŝƌƐ͕ϮϬϭϳ >ĞŽĚĞĚĞůĂƉƌŽƉƌŝĠƚĠŝŶƚĞůůĞĐƚƵĞůůĞŝŶƚĞƌĚŝƚůĞƐĐŽƉŝĞƐŽƵƌĞƉƌŽĚƵĐƚŝŽŶƐĚĞƐƚŝŶĠĞƐăƵŶĞƵƚŝůŝƐĂƚŝŽŶĐŽůůĞĐƚŝǀĞ͘dŽƵƚĞƌĞƉƌĠƐĞŶƚĂƚŝŽŶ ŽƵƌĞƉƌŽĚƵĐƚŝŽŶŝŶƚĠŐƌĂůĞŽƵƉĂƌƚŝĞůůĞĨĂŝƚĞƉĂƌƋƵĞůƋƵĞƉƌŽĐĠĚĠƋƵĞĐĞƐŽŝƚ͕ƐĂŶƐůĞĐŽŶƐĞŶƚĞŵĞŶƚĚĞů͛ĂƵƚĞƵƌŽƵĚĞƐĞƐĂǇĂŶƚƐĐĂƵƐĞ͕ ĞƐƚŝůůŝĐŝƚĞĞƚĐŽŶƐƚŝƚƵĞƵŶĞĐŽŶƚƌĞĨĂĕŽŶƐĂŶĐƚŝŽŶŶĠĞƉĂƌůĞƐĂƌƚŝĐůĞƐ>ϯϯϱͲϮĞƚƐƵŝǀĂŶƚƐĚƵŽĚĞĚĞůĂƉƌŽƉƌŝĠƚĠŝŶƚĞůůĞĐƚƵĞůůĞ͘

(3)

Chapitre 5.

Déficits hydro pluviométriques et implications sur l’activité

agricole en zone soudano-sahélienne au Cameroun :

cas de Maroua et Yagoua (1948-2013)

6DKD)UpGpULF_{7FKLQGMDQJ0HVPLQ}_{(ORXQGRX0HVVL3DXO%DVLOH}_{7FKXHQJD6HXWFKXHQJ7KLHUU\*DwWDQ} 0DQIR'RQDWLHQ$UQDXG_9RXQGLeULF_HW_{0EHYR)HQGRXQJ3KLOLSSHV} _{'pSDUWHPHQWGH*pRJUDSKLH)DFXOWpGHV$UWV/HWWUHVHW6FLHQFHV+XPDLQHV)$/6+8QLYHUVLWpGH<DRXQGp,} _{'pSDUWHPHQWGHJpRJUDSKLHeFROH1RUPDOH6XSpULHXUH8QLYHUVLWpGH0DURXD}_,5$'<DRXQGp 5pVXPp /HFOLPDWVRXGDQRVDKpOLHQUqJQHVXUODUpJLRQGHO¶([WUrPH1RUGGX&DPHURXQTXLDFFXVHXQ SOXVJUDQGUHWDUGVRFLRpFRQRPLTXHGDQVOHSD\V,16/DIDLEOHSURGXFWLYLWpGXPLOLHXHWOD IRUWHFURLVVDQFHGpPRJUDSKLTXHVRQWHQWUHDXWUHVOHVIDFWHXUVH[SOLFDWLIVGHFHWWHVLWXDWLRQ&HWWHUp JLRQVHUDFFRUGHjODEDQGHVDKpOLHQQHGXFRQWLQHQWDIULFDLQFDUDFWpULVpHSDUXQHORQJXHVDLVRQVqFKH 3LHUL'XUDQWOHVGHX[GHUQLqUHVGpFHQQLHVO¶$IULTXHVDKpOLHQQHDFRQQXXQIRLVRQQHPHQW G¶pWXGHVK\GURFOLPDWLTXHVPHWWDQWHQH[HUJXHXQHORQJXHSpULRGHGHVqFKHUHVVHGRPLQpHSDUG¶LP SRUWDQWVGpILFLWVSOXYLRPpWULTXHVDYHFXQLPSDFWVXUWRXWHVOHVDXWUHVFRPSRVDQWHVGXPLOLHXQDWXUHO HWKXPDLQ &HWWHpWXGHV¶DSSXLHVXUXQHVpULHFKURQRORJLTXHGHGRQQpHVSOXYLRPpWULTXHVGLVSRQLEOHVSRXUOHV VWDWLRQVGH0DURXDHW<DJRXDSRXULGHQWLILHUOHVULVTXHVOLpVjODUpSDUWLWLRQMRXUQDOLqUHPHQVXHOOH DQQXHOOHHWGpFDGDLUHGHVSUpFLSLWDWLRQVVXUO¶DFWLYLWpDJULFROHHQ]RQHVRXGDQRVDKpOLHQQHDX&DPH URXQ,OHQUHVVRUWTX¶DYDQWGDWHGHODSUHPLqUHUXSWXUHGHVWDWLRQQDULWpODSOXYLRPpWULHGHOD ]RQHpWDLWH[FpGHQWDLUHDYHFXQHSUpGRPLQDQFHG¶DQQpHVKXPLGHV¬SDUWLUGHFRPPHQFHXQH ORQJXHSpULRGHVqFKHPDUTXpHSDUXQHIDLEOHSOXYLRPpWULH/HVGRQQpHVSUpVHQWHQWXQHUHSULVHGH O¶KXPLGLWpGqVOHGpEXWGHODGpFHQQLHVDQVWRXWHIRLVDWWHLQGUHODVLWXDWLRQG¶DYDQW3HQGDQW ODSpULRGHVqFKHO¶DJULFXOWXUHSOXYLDOHHVWSURIRQGpPHQWpSURXYpHHWOHVSRSXODWLRQVGRLYHQWDYDLHQW UHGRXEOpG¶HIIRUWVGDQVOHVFXOWXUHVGHFRQWUHVDLVRQQRWDPPHQWOHVRUJKR)RWVLQJ/¶LQVWD ELOLWpGHODVDLVRQGHVSOXLHVDYHFGHVUHWRXUVWDUGLIVHWOHVILQVSUpFRFHVPHQDFHDXVVLELHQO¶DJULFXO WXUHSOXYLDOHTXHO¶DJULFXOWXUHLQRQGpHGHGpFUXHHWPrPHGHFRQWUHVDLVRQ/HVSDXVHVSOXYLRPp WULTXHVGHSOXVHQSOXVQRPEUHXVHVHWORQJXHVUHQIRUFHQWOHFDUDFWqUHDOpDWRLUHGHO¶DJULFXOWXUHSOX YLDOH/DUHFUXGHVFHQFHGHVIRUWHVSOXLHVHVWjO¶RULJLQHG¶LQRQGDWLRQVFDXVDQWGHVSHUWHVFDWDVWUR SKLTXHVVXUO¶HQVHPEOHGXV\VWqPHGHSURGXFWLRQ 0RWVFOpVDJULFXOWXUHSOXYLDOHSDXVHSOXYLRPpWULTXHVRUJKR]RQHVRXGDQRVDKpOLHQQH ,QWURGXFWLRQ /HVGLIIpUHQWVUDSSRUWVSXEOLpVSDUOH*,(&GHSXLVRQWSHUPLVG¶DIILQHUOHVREVHUYDWLRQVVXU OHVPDQLIHVWDWLRQVGHVFKDQJHPHQWVFOLPDWLTXHV$XSODQPRQGLDOLOV¶DJLWGHO¶DXJPHQWDWLRQGHV WHPSpUDWXUHVjODVXUIDFHGHODWHUUHGHO¶pOpYDWLRQGXQLYHDXGHODPHUGHVSHUWXUEDWLRQVSOXYLRPp WULTXHVGXUHQIRUFHPHQWGHVPDVVHVG¶DLUWURSLFDOHVHWF$XQLYHDXUpJLRQDOFKDTXHFRQWLQHQWHQ IRQFWLRQ GH VHV UpDOLWpV ELRSK\VLTXHV HW KXPDLQHV VXELW GH PDQLqUH VLQJXOLqUH FHV FKDQJHPHQWV

(4)

/¶$IULTXHHVWYLFWLPHGHODSURJUHVVLRQGHODVqFKHUHVVHODEDLVVHGHVUHVVRXUFHVHQHDXODUHFUXGHV FHQFHGHVLQRQGDWLRQVO¶LQVWDELOLWpGHVDSOXYLRPpWULH«/HVDKHOHVWOD]RQHGXFRQWLQHQWODSOXV WRXFKpHSDUFHVGLIIpUHQWHVPDQLIHVWDWLRQV*,(&'LYHUVHVREVHUYDWLRQVIDLWHVSDUOHFHQWUH UpJLRQDO$*5+<0(7HWG¶DXWUHVDXWHXUV+XOPH-DQLFRWHWDO/H%DUEpHWDO IRQWpWDWG¶XQHEDLVVHGHVSUpFLSLWDWLRQVDXVDKHOGHSXLVODILQGHVDQQpHVDYHFXQHUHSULVH GHO¶KXPLGLWpHQWDPpHGqVOHGpEXWGHVDQQpHV6LFHWWHVLWXDWLRQHVWFRQFRUGDQWHGDQVODSDUWLH 2XHVWGXVDKHOLOHVWHQFRUHQpFHVVDLUHGHGHQVLILHUOHVpWXGHVDXFHQWUHXQHLPSRUWDQWHYDULDWLRQ VSDWLDOHGHVSUpFLSLWDWLRQVpWDQWREVHUYDEOHGDQVFHWWHSDUWLHGXFRQWLQHQW /¶DFWLYLWpDJULFROHHVWVDQVFRQWHVWHOHVHFWHXUGHO¶pFRQRPLHOHSOXVWRXFKpSDUFHVFKDQJHPHQWV GHSOXYLRPpWULHUHVVHQWLHGDQVOHVDKHOHQ$IULTXH*,(&/¶H[WHQVLRQGHVWHUUHVDULGHVOD EDLVVHGHVUHVVRXUFHVHQHDXHWO¶DXJPHQWDWLRQGHVWHPSpUDWXUHVDIIHFWHQWGLUHFWHPHQWODSURGXFWLYLWp GHWRXWHVOHVVSpFXODWLRQV(QRXWUHODG\QDPLTXHTXHFRQQDLWODVDLVRQGHVSOXLHVSRUWHXQVpULHX[ FRXSjO¶DJULFXOWXUHSOXYLDOHTXLUHSUpVHQWHSUqVGHGHVWHUUHVFXOWLYpHVHWGHVFpUpDOHV FRQVRPPpHVGDQVODSDUWLHVRXGDQRVDKpOLHQQHGHO¶$IULTXH6XOWDQHWDO 'DQVODUpJLRQGHO¶([WUrPH1RUGGX&DPHURXQ/HWDX[G¶LQYDVLRQGHVFKDPSVSDUOHVFKHQLOOHV OHVFDVGHUpVHPLVOHVVXSHUILFLHVGpYDVWpHVSDUOHVLQRQGDWLRQVODEDLVVHGHVUHQGHPHQWVSDUKDOH IOpWULVVHPHQW GHV FXOWXUHV VRQW TXHOTXHVXQV GHV LQGLFDWHXUV PLV HQ H[HUJXH SDU $QRXJXH HW DO

GDQVXQUDSSRUWGHOD*,=/¶REMHFWLIGHFHWUDYDLOHVWGHSURFpGHUjXQHDQDO\VHILQHGHV GRQQpHVGHSOXYLRPpWULHMRXUQDOLqUHVXUSUqVGHVHSWGpFHQQLHVSRXULGHQWLILHUOHVDQRPDOLHVSOXYLR PpWULTXHVHWOHXUVLPSDFWVUHVSHFWLIVHWRXFXPXOpVVXUO¶DFWLYLWpDJULFROH &DGUHG¶pWXGHHWGpPDUFKHPpWKRGRORJLTXH /HGRPDLQHVRXGDQRVDKpOLHQFDPHURXQDLVFDGUHSK\VLTXHHWKXPDLQ /D]RQHVRXGDQRVDKpOLHQQHGX&DPHURXQFRUUHVSRQGDXSODQDGPLQLVWUDWLIjODUpJLRQGHO¶([ WUrPH1RUG(OOHV¶pWHQGDXGHOjVXq_{SDUDOOqOH1RUGHWURPSWDYHFOHGRPDLQHWURSLFDOKXPLGH} UpJQDQWDXVXGDYHFODEDLVVHGHODSOXYLRPpWULHHWO¶DXJPHQWDWLRQGHVWHPSpUDWXUHVPR\HQQHVILJXUH *OREDOHPHQW LO V¶DJLW G¶XQ PLOLHX FKDXG DYHF XQH FRQFHQWUDWLRQ GHV SUpFLSLWDWLRQV VXU WURLV j TXDWUHPRLVHWXQHORQJXHVDLVRQVqFKH/HVFRXUVG¶HDXmayosGHFHPLOLHXSUpVHQWHQWXQpFRXOH PHQWLQWHUPLWWHQW6HXOOHIOHXYH/RJRQHSUHQDQWVDVRXUFHGDQVO¶$GDPDRXDHWSURILWDQWGHO¶pWHQGXH GHVRQEDVVLQPDLQWLHQWVRQpFRXOHPHQWWRXWHO¶DQQpHDYHFXQHEDLVVHGUDVWLTXHGHVRQGpELWHQWUH GpFHPEUHHWMXLQP_{V$XSODQWRSRJUDSKLTXHFHWWHUpJLRQHVWFDUDFWpULVpHSDUVRQpWDJHPHQW} /HVPRQWV0DQGDUDjO¶2XHVWGRPLQHQWDYHFGHVDOWLWXGHVYDULDQWHQWUHHWP(QFRQWUHEDV VHWURXYHOHSLpPRQWTXLIDLWODWUDQVLWLRQDYHFXQHYDVWHSODLQHLQRQGDEOHLQVFULWHGDQVODOLVWHGHV VLWHVKXPLGHVGXPRQGHHQUHVSHFWGHVLQGLFDWLRQVGHOD&RQYHQWLRQGH5DPVDU

(5)

Figure 1. Localisation du domaine tropical soudano-sahélien au Cameroun

$XSODQKXPDLQOD5pJLRQGHO¶([WUrPH1RUGIDLWILJXUHGHJUDQGEDVVLQGHSHXSOHPHQWDX&D PHURXQ$XWURLVLqPHUHFHQVHPHQWJpQpUDOGHODSRSXODWLRQHWGHO¶KDELWDW5*3+PHQpHQ VDSRSXODWLRQVHFKLIIUDLWjKDELWDQWV(QFHWWHSRSXODWLRQpWDLWSURMHWpHj KDELWDQWVVRLWXQHGHQVLWpGHKDELWDQWVNPð(QFHTXLFRQFHUQHO¶pFRQRPLHOHVHFWHXUSULPDLUH HVWGRPLQpSDUO¶DJULFXOWXUHO¶pOHYDJHERYLQFDSULQSRUFLQYRODLOOH«HWODSrFKH8QHGHPLGL ]DLQHGHVSpFXODWLRQVDJULFROHVUHSUpVHQWHSOXVGHGHVVXSHUILFLHVFXOWLYpHVILJXUH7RXWHV OHVDFWLYLWpVSULPDLUHVVRQWGRPLQpHVSDUGHVSUDWLTXHVH[WHQVLYHVHVVHQWLHOOHPHQWGpSHQGDQWHVGHV FRQGLWLRQVGX PLOLHXQDWXUHO/HFRPPHUFHOHWUDQVSRUWO¶DUWLVDQDWHWOHWRXULVPHVRQWpJDOHPHQW IORULVVDQWV,O IDXWUHPDUTXHU TXH OHV VWUDWpJLHV SRXU O¶DWWHLQWH GHV 2EMHFWLIV GX 0LOOpQDLUH SRXUOH 'pYHORSSHPHQW20'RQWFRQQXSHXGHVXFFqVGDQVFHWWHUpJLRQ(QHIIHWGHODSRSXODWLRQ YLWHQGHVVRXVGXVHXLOGHSDXYUHWpHWVHXOHPHQWGHVMHXQHVGHPRLQVGHDQVVRQWVFRODULVpV ,16/DIRUWHFURLVVDQFHGpPRJUDSKLTXHO¶LQVpFXULWpODGpJUDGDWLRQGHO¶HQYLURQQHPHQWDYHF OHVHIIHWVGHVFKDQJHPHQWVFOLPDWLTXHVVRQWHQWUHDXWUHVOHVIDFWHXUVjO¶RULJLQHGHVPDXYDLVHVFRQGL WLRQVGHYLHGDQVFHWWHUpJLRQGX&DPHURXQ

(6)

Figure 2.

Superficies des principales spéculations agricoles dans la Région de l’Extrême-Nord du Cameroun

(source : Annuaire statistique du Cameroun – données moyennes 2009-2011)

&ROOHFWHGHGRQQpHVHWDQDO\VH /HVGRQQpHV &HWWHpWXGHUHSRVHVXUGHVGRQQpHVSOXYLRPpWULTXHVGHVVWDWLRQVGH<DJRXDHW0DURXDGDQVOD UpJLRQGHO¶([WUrPH1RUGGX&DPHURXQ,OV¶DJLWGHVTXDQWLWpVMRXUQDOLqUHVGHSUpFLSLWDWLRQV&HV GRQQpHVSURYLHQQHQWGHO¶XQLWpWHFKQLTXHGHOD6RFLpWpGH'pYHORSSHPHQWGX&RWRQDX&DPHURXQ 62'(&2721TXLHVWXQHLPSRUWDQWHDJURLQGXVWULHHQDFWLYLWpGDQVOD]RQH/DSpULRGHG¶REVHU YDWLRQV¶pWHQGGHHQVRLWSOXVGHVHSWGpFHQQLHVGRQQDQWODSRVVLELOLWpGHFRQGXLUHXQ HQVHPEOHGHWHVWVWDWLVWLTXHVSRXUH[WUDLUHGHVLQIRUPDWLRQVXWLOHV'¶DXWUHVGRQQpHVVRQWLVVXHVGHOD UHYXHGHODOLWWpUDWXUHVXUOHVDKHODIULFDLQPrPHVLODSDUWLHFDPHURXQDLVHUHVWHODPRLQVpWXGLpHSDU UDSSRUWDX[SD\VG¶$IULTXHGHO¶2XHVW/¶DQQXDLUHVWDWLVWLTXHGX&DPHURXQGHHWTXHOTXHVQX PpURVG¶$JULVWDWRQWpWpH[SORLWpVSRXUOHVGRQQpHVDJULFROHV'HVGHVFHQWHVGHWHUUDLQVGDQVOHGp SDUWHPHQWGX0D\R'DQD\HQHWOHSDUFRXUVGXGpSDUWHPHQWGX'LDPDUpHQRQWSHUPLVOD FROOHFWHGHVGRQQpHVGHWHUUDLQ 5.1.2.1.1. Les traitements /HVGRQQpHVSOXYLRPpWULTXHVFROOHFWpHVRQWIDLWO¶REMHWG¶XQHQVHPEOHGHWUDLWHPHQWYLVDQWjUHV VRUWLUOHVDQRPDOLHVD\DQWXQLPSDFWVXUODSURGXFWLRQDJULFROH/HVDSSOLFDWLRQV&KURQR6WDWHW([FHO RQWpWpXWLOLVpHV

5.1.2.1.2. Test de détection de rupture

,O SHUPHW G¶LVROHU DX VHLQ GH OD VpULH VWDWLVWLTXH pWXGLpH GHV VHJPHQWV GH PDQLqUH j FH TXH OHV PR\HQQHVFDOFXOpHVVXUFKDTXHVHJPHQWVRLHQWVLJQLILFDWLYHPHQWGLIIpUHQWHV+XEHUWHWDO /¶DSSOLFDWLRQ&KURQRVWDWGpYHORSSpHSDUO¶805+\GURVFLHQFHVGH0RQWSHOOLHUVSpFLDOLVpH GDQVO¶DQDO\VHGHVpULHVFKURQRORJLTXHVSURSRVHXQHQVHPEOHGHWHVWGHGpWHFWLRQGHUXSWXUHVOHWHVW GH%XLVKDQGHWO¶HOOLSVHGH%RLVODPpWKRGHQRQSDUDPpWULTXHGH3HWWLWWODPpWKRGHED\pVLHQQHGH /HHHW+HJKLQLDQHWOD6HJPHQWDWLRQGH+XEHUW

5.1.2.1.3. Délimitation de la saison des pluies

3RXUGpWHUPLQHUOHGpEXWGHODVDLVRQGHVSOXLHVTXLFRUUHVSRQGjODSpULRGHG¶HQVHPHQFHPHQWGHV WHUUHVSOXVLHXUVDXWHXUVSURSRVHQWGHVPpWKRGHVGRQWO¶HIILFDFLWpGpSHQGGHODSUpFLVLRQGHVGRQQpHV KLVWRULTXHVGLVSRQLEOHVHWGHVSURJUDPPHVGHWUDLWHPHQWPLVHQDSSOLFDWLRQ(QPLOLHXVDKpOLHQ6L YDNXPDUHW(USLFXPHWDORQWSURSRVpGHVPpWKRGHVSUpVHQWDQWXQLQWpUrWFHUWDLQ SRXUOHVDFWLYLWpVDJULFROHV/DPpWKRGHGH6LYDNXPDUTXHQRXVXWLOLVRQVGDQVFHWWHpWXGHDpWpGpYH ORSSpHVXUODEDVHG¶REVHUYDWLRQVIDLWHVVXUOHPLOHQPLOLHXVDKpOLHQHWVRXGDQLHQ(OOHDFRQQXXQ LPSRUWDQWVXFFqVGDQVOHVSD\VRXHVWDIULFDLQVJUkFHjVDIDFLOLWpG¶DSSOLFDWLRQHWVRQFDUDFWqUHDJUR QRPLTXH2]HUHWDO3RXUFHWWHPpWKRGHOHFULWqUHIL[pSRXUOHGpEXWGHODVDLVRQGHSOXLH

0LOVRUJKR 1LpEp $UDFKLGH 0DwV 5L] +DULFRW $XWUHV

FXOWXUHV

6XSHUILFLH

0

LOOLHUVKD

(7)

HVWGHPPUHFXHLOOLVHQWURLVMRXUVFRQVpFXWLIVDSUqVOHHUPDLVDQVSpULRGHVqFKHVXSpULHXUHj MRXUV SHQGDQW OHV MRXUV VXLYDQWV /D ILQ GH OD VDLVRQ GHSOXLH HVW IL[pH DX MRXU RX DSUqV OH HU VHSWHPEUHLO\DSOXVGHSOXLHVSHQGDQWXQHSpULRGHMRXUV

5.1.2.1.4. Recensement des pauses pluviométriques

/DFRQILJXUDWLRQFOLPDWLTXHGXPLOLHXVDKpOLHQDYHFODIDLEOHVVHGHVHVSUpFLSLWDWLRQVSRQFWXpHV SDUGHVVpTXHQFHVVqFKHVSHQGDQWODVDLVRQGHVSOXLHVOLPLWHOHVSRVVLELOLWpVDJURQRPLTXHVGHOD]RQH /HVFXOWXUHVSOXYLHXVHVVRQWHVVHQWLHOOHPHQWGHVFpUpDOHVUL]PDwVPLOVRUJKR«/HPDwVVHUpYqOH FRPPHODSODQWHODSOXVVHQVLEOHDX[SDXVHVSOXYLRPpWULTXHV/RUVTXHSHQGDQWMRXUVFRQVpFXWLIV DXFXQHSOXLHQ¶HVWHQUHJLVWUpHO¶LQFLGHQFHSHXWrWUHOHUDOHQWLVVHPHQWGHODFURLVVDQFHRXODPDXYDLVH pSLDLVRQHQIRQFWLRQGHODSpULRGHG¶RFFXUUHQFH/RUVTXHODSDXVHVHSURORQJHDXGHOjG¶XQHVHPDLQH WRXWHVOHVSODQWHV\FRPSULVOHVSOXVUpVLVWDQWHVPLOVRUJKRHWQLpEpVRQWWRXFKpHV3RXUFHWWHpWXGH OHVFRXUWHVSDXVHVVRQWFRPSULVHVHQWUHHWMRXUVWDQGLVTXHOHVORQJXHVSDXVHVGXUHQWGHj MRXUV

5.1.2.1.5. Le regroupement des évènements pluvieux en classes

/¶2UJDQLVDWLRQGHOD0pWpRURORJLH0RQGLDOH200UHJURXSHOHVSOXLHVHQTXDWUHFODVVHV3 jPP3jPP3jPPHW3!PP/¶DQDO\VHGHVGRQQpHVGHVVWDWLRQV GH0DURXDHW<DJRXDFKRLVLHVSRXUFHWWHpWXGHDSHUPLVGHUHVVRUWLUO¶HQVHPEOHGHFHVFODVVHVSOX YLRPpWULTXHV2QUHPDUTXHXQHIRUWHRFFXUUHQFHGHV3HWXQHWUqVIDLEOHRFFXUUHQFHGHV3G¶ROH UHJURXSHPHQWGHV3HW3 3UpVHQWDWLRQHWDQDO\VHGHVUpVXOWDWV /DG\QDPLTXHSOXYLRPpWULTXH (QPR\HQQHSRXUODSpULRGHOHFXPXODQQXHOGHSUpFLSLWDWLRQVHVWGHPPj<DJRXD HWPPj0DURXD&HWpWDWPR\HQGLVVLPXOHXQHIRUWHYDULDELOLWpLQWHUDQQXHOOHDYHFGHVWHQGDQFHV LGHQWLILDEOHVSRXUFHUWDLQHVSpULRGHV/DILJXUH$ %SUpVHQWHO¶pYROXWLRQLQWHUDQQXHOOHGHVSUpFL SLWDWLRQVSRXUOHVGHX[VWDWLRQVFKRLVLHVjWUDYHUVO¶,QGLFH6WDQGDUGLVpGHV3UpFLSLWDWLRQV63, Figure 3.

SPI des données pluviométriques annuelles de Maroua et Yagoua

$ 0DURXD % <DJRXD 3RXUXQHSpULRGHG¶REVHUYDWLRQGHDQQpHVj<DJRXDDQQpHVSUpVHQWHQWGHVH[FpGHQWVSOX YLRPpWULTXHVHWGHVGpILFLWV3DUPLOHVDQQpHVH[FpGHQWDLUHVVRQWFDUDFWpULVpHVSDUXQHKXPLGLWp H[WUrPH63,!HWDQQpHVSUpVHQWHQWGHVKXPLGLWpVIRUWHV63,,OIDXWUHPDUTXHUTXH OHVDQQpHVKXPLGHVVHUHFHQVHQWHQPDMRULWpDXGpEXWGHODVpULHVWDWLVWLTXHQRWDPPHQWGDQVOHVDQQpHV HW7RXWHIRLVjODILQGHODVpULHO¶DQQpHSUpVHQWHDXVVLXQHIRUWHKXPLGLWp/HVDQQpHV HWIXUHQWOHVDQQpHVG¶H[WUrPHVqFKHUHVVH63,6L[DXWUHVDQQpHVSUpVHQWHQWXQH VqFKHUHVVHIRUWH63,HWOHVDXWUHVDQQpHVPRQWUHQWXQHVqFKHUHVVHPRGpUpH63,

(8)

/DVLWXDWLRQGH0DURXDHVWSOXVDOpDWRLUHHWODWHQGDQFHGRPLQDQWHHVWO¶DPSOHXUGHODVpFKHUHVVHGH ODGpFDGH/¶DQQpHIXWH[WUrPHPHQWDUURVpHHWDQQRQoDLWXQHSpULRGHG¶H[FpGHQWV SOXYLRPpWULTXHVDYHFXQHIRUWHSUpGRPLQDQFHG¶DQQpHVKXPLGHV /HVDQQpHVG¶H[WUrPHKXPLGLWpV¶LOOXVWUHQWSDUGHVFUXHVFDWDVWURSKLTXHVTXLDIIHFWHQWO¶HQVHPEOH GHO¶DSSDUHLOGHSURGXFWLRQ/HGHUQLHUFDVHQGDWHHVWFHOXLGHO¶DQQpH(QFHWWHDQQpHWRXVOHV VL[GpSDUWHPHQWVGHODUpJLRQRQWpWpWRXFKpVSDUOHVLQRQGDWLRQV/¶DUURQGLVVHPHQWGH.DL.DLXQH GHVORFDOLWpVOHVSOXVWRXFKpHVDYDLWSHUGXKDGHUL]KDGHVRUJKRKDGHPLO KDGHQLpEpHWWRXWHVOHVSpSLQLqUHVGXVRUJKRGHFRQWUHVDLVRQIXUHQWGpWUXLWHVGRQQpHVGHOD 'pOpJDWLRQ5pJLRQDOHGX0,1$'(5GHOD5pJLRQGHO¶([WUrPH1RUG $OWHUQDQFHGHVSpULRGHVVqFKHVHWKXPLGHVHQWUHHW 'HVWHVWVGHUXSWXUHVDSSOLTXpVDX[GRQQpHVGHVVWDWLRQVGH0DURXDHW<DJRXDSHUPHWWHQWG¶LGHQ WLILHUSOXVLHXUVSpULRGHVGDQVODVpULHVWDWLVWLTXHGHGRQQpHV2QUHPDUTXHTXHO¶DQQpHSUpVHQWH ODSULQFLSDOHUXSWXUHDYHFXQHGHQVLWpGHSUREDELOLWpDSRVWpULRULGHSRXUFHTXLHVWGHVGRQQpHV GH<DJRXDILJXUH Figure 4.

Procédure de Lee et Heghinien de détection de rupture dans la série statistique des données pluviométrique des stations de Maroua et Yagoua

$ <DJRXD % 0DURXD /HVpWXGHVGXFHQWUHUpJLRQDO$*5+<0(7GH1LDPH\DX1LJHUVLWXHQWpJDOHPHQWjFHWWH GDWHODSULQFLSDOHUXSWXUHSOXYLRPpWULTXHDX6DKHO$YDQWOHVSUpFLSLWDWLRQVpWDLHQWDERQ GDQWHV/DUXSWXUHVXUYHQXHHQPDUTXDLWOHGpEXWG¶XQHSpULRGHGHIRUWHVqFKHUHVVHDYHFXQH LPSRUWDQWHGLPLQXWLRQGHODSOXYLRPpWULHWDEOHDX Tableau 2.

Caractérisation des segments de la série statistique (Yagoua)

6HJPHQWV 0R\HQQHDQQXHOOHGH SOXYLRPpWULH eFDUWW\SH Į &RHIILFLHQWGHYDULD WLRQFYHQ ± ± 7RWDO±

(Source : Analyse des données pluviométriques)

$SSOLTXpHDX[GRQQpHVGH0DURXDODSURFpGXUHGH/HHHW+HJKLQLHQGpWHFWHODSULQFLSDOHUXSWXUH HQILJXUH$LQVLFHWWHDQQpHPDUTXHUDLWODILQGHODORQJXHSpULRGHGHVqFKHUHVVHDYHFXQH UHSULVHGHO¶KXPLGLWp3OXVLHXUVDXWHXUV/DEHOHWDO2]HUHWDOV¶DFFRUGHQWG¶DLOOHXUV

(9)

SRXUGpPRQWUHUTXHVLODVqFKHUHVVHFRQWLQXHHQ$IULTXHGHO¶2XHVWHOOHQ¶HVWSOXVG¶DFWXDOLWpGDQVOD SDUWLHRULHQWDOHGX6DKHORGHSXLVSOXVGHGHX[GpFHQQLHVO¶KXPLGLWpHVWGHUHWRXU&HWWHPrPHUpDOLWp UHVVRUWGHO¶DQDO\VHGpFDGDLUHWDEOHDX

Tableau 3.

Répartition décadaire des données pluviométriques de Maroua et Yagoua

'pFDGH 0R\HQQH GpFDGDLUH eFDUWW\SH &RHIILFLHQWGHYDULD WLRQ

0DURXD <DJRXD 0DURXD <DJRXD 0DURXD <DJRXD

(Source : Analyse des données pluviométriques)

/HVGHX[GpFHQQLHVGHVqFKHUHVVHIXUHQWWUqVSUpMXGLFLDEOHVSRXUO¶DJULFXOWXUHSOXYLDOH GDQVWRXWOH6DKHODIULFDLQ)$2'DQVODSODLQHLQRQGDEOHGHODUpJLRQGHO¶([WUrPH1RUGGX &DPHURXQO¶DJULFXOWXUHLQRQGpHUL]LFXOWXUHDYDLWDXVVLFRQQXXQUHFXOjFDXVHGHODGLPLQXWLRQGHV VXSHUILFLHVDQQXHOOHPHQWVXEPHUJpHV)RWVLQJVLWXHjFHWWHSpULRGHO¶H[WHQVLRQGHODFXOWXUH GXVRUJKRGHFRQWUHVDLVRQGDQVFHWWH]RQHMuskwari)/DEDLVVHGHODSOXYLRPpWULHFRXSOpHjXQH IRUWHYDULDELOLWpLQWHUDQQXHOOHDYDLWGLPLQXpODSURGXFWLYLWpGXPDwVGXPLOHWWRXWHVOHVDXWUHVFXOWXUHV GHVDLVRQGHSOXLHVOHVRUJKRGHFRQWUHVDLVRQV¶pWDLWDORUVLOOXVWUpFRPPHDWRXWSULQFLSDOGDQVOD VWUDWpJLHGHPDLQWLHQGHODVpFXULWpDOLPHQWDLUH<RXQJHW0RWWUDP)RWVLQJHW0DLQDP  8QUHFRXSHPHQWGHVGRQQpHVGHOD'LUHFWLRQGHV(QTXrWHVHWGHV6WDWLVWLTXHV$JULFROHV'(6$ GX0LQLVWqUHGHO¶$JULFXOWXUHHWGX'pYHORSSHPHQW5XUDO0,1$'(5PRQWUHTX¶HQODVXSHU ILFLH FRQVDFUpH j OD SURGXFWLRQ GX PDwV HW GX PLOVRUJKR GDQV OD 5pJLRQ GH O¶([WUrPH1RUG pWDLW UHVSHFWLYHPHQWGHKDHWGHKD8QHGRX]DLQHG¶DQQpHVSOXVWDUGOHPDwVIUDQFKLVVDLW jSHLQHODEDUUHGHKDDORUVTXHOHPLOVRUJKRVHUDSSURFKDLWGXPLOOLRQG¶KDILJXUH

Figure 5.

Évolution des superficies de maïs et mil/sorgho dans la Région de l’Extrême-Nord du Cameroun entre 2000-2012

(Source : DESA et INS)

0LOOLHUVGKD &DPSDJQH 0DwV 0LO6RUJKR

(10)

,OIDXWUHPDUTXHUTXHGDQVODSURGXFWLRQGHFHVVWDWLVWLTXHVOD'(6$UHJURXSHOHPLOHWOHVRUJKR SDUFHTX¶LOVVRQWVRXYHQWSUDWLTXpVVXUOHVPrPHVSDUFHOOHV/DSUpVHQWDWLRQHQIRQFWLRQGHVFDP SDJQHVPRQWUHTXHODGHX[LqPHF¶HVWjGLUHFHOOHGHODVDLVRQVqFKHOHVRUJKRGHFRQWUHVDLVRQ UHSUpVHQWHSXLVOHPLOHWOHVRUJKRSOXYLDX[XQLTXHPHQW /¶LQVWDELOLWpVDLVRQQLqUH /DSURJUDPPDWLRQGHVDFWLYLWpVDJULFROHVHVWWULEXWDLUHGXFRPSRUWHPHQWGHODSOXYLRPpWULHORFDOH /HVRSpUDWLRQVGHVHPLVG¶HQWUHWLHQGHVFXOWXUHVHWPrPHOHPRLVVRQQDJHFRUUHVSRQGHQWjGHVSp ULRGHVSUpFLVHVGHODVDLVRQGHVSOXLHVRXGHODVDLVRQVqFKH$ORUVTXHOHVSUHPLqUHVSOXLHVV¶DEDWWHQW j0DURXDGqVOHDYULOODPpWKRGHGH6LYDNXPDUVLWXHOHGpEXWGHODVDLVRQGHVSOXLHVDXPDLHQ PR\HQQH$YDQWFHWWHGDWHRQUHPDUTXHXQHIUpTXHQFHSHXFRQVLGpUDEOHGHIDLEOHVSOXLHVVpSDUpHVGH ORQJXHVSpULRGHVVqFKHV/DILQGHODSpULRGHKXPLGHVHVLWXHHQPR\HQQHDXRFWREUH¬ODVWDWLRQ GH<DJRXDODGDWHPR\HQQHGHGpEXWGHODVDLVRQGHSOXLHHVWDXPDLHWODVqFKHUHVVHV¶LQVWDOOH GqVOHRFWREUH2QUHPDUTXHXQHIDLEOHYDULDELOLWpVSDWLDOHQRQREVWDQWODGLIIpUHQFHTXLH[LVWHHQWUH OHVFXPXOVPR\HQVLQWHUDQQXHOVGHVGHX[VWDWLRQV$LQVLODSpULRGHKXPLGHGXUHHQPR\HQQH MRXUV $XSODQLQWHUDQQXHORQUHPDUTXHXQHFHUWDLQHYDULDELOLWpDXVVLELHQGXGpEXWTXHGHODILQGHOD VDLVRQGHVSOXLHV$ORUVTXHSRXUFHUWDLQHVDQQpHVOHVSOXLHVVRQWSUpFRFHVG¶DXWUHVDQQpHVFRQQDLV VHQWXQLPSRUWDQWUHWDUGGHVSUHPLqUHVSOXLHV,OHQHVWGHPrPHGHODILQGHVSUpFLSLWDWLRQVTXLHVW SDUIRLVDQWpULHXUHDXPRLVGHVHSWHPEUH'¶DXWUHVDQQpHVQRWDPPHQWKXPLGHVFRQQDLVVHQWXQUDOORQ JHPHQW GHVSOXLHV MXVTX¶j OD GHUQLqUH GpFDGH GX PRLV G¶RFWREUH /D ILJXUH SUpVHQWH O¶pYROXWLRQ LQWHUDQQXHOOHGHVGDWHVGHGpEXWHWGHILQGHODVDLVRQGHVSOXLHVSRXUOHVVWDWLRQVGH0DURXDHW<DJRXD

Figure 6.

Début et fin de la saison des pluies aux stations de Maroua et Yagoua

,OHVWGLIILFLOHG¶pWDEOLUHQFRQFOXVLRQXQFKDQJHPHQWSRXUFHTXLHVWGXGpEXWHWGHODILQGHOD VDLVRQGHVSOXLHVDXVVLELHQjODVWDWLRQGH0DURXDTX¶jFHOOHGH<DJRXD2QUHPDUTXHSOXW{WXQH YDULDWLRQHUUDWLTXHGHVGRQQpHVDXWRXUGHODPR\HQQHVDQVSUpVHQWHUXQHWHQGDQFHPRGpOLVDEOH2Q UHPDUTXHWRXWHIRLVXQUHWDUGGHSOXVHQSOXVSURQRQFpSRXUFHTXLFRQFHUQHOHGpEXWGHODVDLVRQGHV SOXLHVj<DJRXD ϮϭͲŵĂƌƐ ϭϬͲŵĂŝ ϮϵͲũƵŝŶ ϭϴͲĂŽƸƚ ϬϳͲŽĐƚ ϮϲͲŶŽǀ ϭϵϰϴ ϭϵϱϯ ϭϵϱϴ ϭϵϲϯ ϭϵϲϴ ϭϵϳϯ ϭϵϳϴ ϭϵϴϯ ϭϵϴϴ ϭϵϵϯ ϭϵϵϴ ϮϬϬϯ ϮϬϬϴ ϮϬϭϯ 0DURXD 'pEXW )LQ ϯϭͲũĂŶǀ ϭϬͲŵĂŝ ϭϴͲĂŽƸƚ ϮϲͲŶŽǀ ϭϵϰϴ ϭϵϱϯ ϭϵϱϴ ϭϵϲϯ ϭϵϲϴ ϭϵϳϯ ϭϵϳϴ ϭϵϴϯ ϭϵϴϴ ϭϵϵϯ ϭϵϵϴ ϮϬϬϯ ϮϬϬϴ ϮϬϭϯ <DJRXD &ŝŶ ĠďƵƚ

(11)

/DGLIILFXOWpSRXUOHVSRSXODWLRQVjGpWHUPLQHUOHGpEXWGHODVDLVRQGHVSOXLHVSRXUODPLVHHQWHUUH GHVVHPHQFHVVHSRVHFKDTXHDQQpH/HVDXWRULWpVDJULFROHVSHLQHQWDXVVLjSURSRVHUGHVGDWHVTXL VRLHQWFRQYHQDEOHV/HVSUHPLqUHVSOXLHVLQWHUYLHQQHQWSDUIRLVWUqVW{WDXPRLVG¶DYULOHWPrPHHQ PDUVHWVRQWVXLYLHVSDUGHORQJXHVSpULRGHVVqFKHV/DILJXUHSUpVHQWHO¶pFDUWHQWUHODSUHPLqUH SOXLHHWOHGpEXWHIIHFWLIGHODVDLVRQGHSOXLHGDQVOHVGHX[VWDWLRQV Figure 7.

Écart entre la date de la première pluie et le début de la saison des pluies

'qVOHVSUHPLqUHVSOXLHVOHVSRSXODWLRQVLQWHQVLILHQWOHVDFWLYLWpVGHSUpSDUDWLRQGHVWHUUHVSRXU OHVVHPLV,OV¶DJLWpJDOHPHQWG¶XQHSpULRGHGHGRXWH3OXVHOOHVHSURORQJHSOXVOHULVTXHGHVHPHU DYDQWOHGpEXWHIIHFWLIGHODVDLVRQGHVSOXLHVHVWJUDQG/¶DQDO\VHGpFDGDLUHSHUPHWGHUHOHYHUTX¶HQ PR\HQQHMRXUVV¶pFRXOHQWHQWUHODSUHPLqUHSOXLHHWOHGpEXWHIIHFWLIGHODVDLVRQGHVSOXLHV/D GpFHQQLHSUpVHQWHO¶pFDUWOHSOXVpOHYpMRXUV/DGpFHQQLHD\DQWGpEXWpHQV¶LQV FULWGDQVFHWWHFRQWLQXLWp8QWHQGDQFHDXUHQIRUFHPHQWGHODYDULDWLRQHQWUHOHVGHX[H[WUpPLWpVVH GHVVLQHHWV¶LPSRVHFRPPHXQQRXYHDXFKDOOHQJHDX[DJULFXOWHXUV /DILQGHODVDLVRQGHVSOXLHVVHVLWXHHQWUHVHSWHPEUHHWRFWREUH/RUVTXHOHUHWRXUGHODVqFKHUHVVH HVWSUpFRFHOHVSODQWHVSHLQHQWjERXFOHUOHXUVF\FOHVHWOHVFRQVpTXHQFHVVHIRQWVHQWLUVXUOHVUpFROWHV /¶DQQpHSDUH[HPSOHDYDLWFRQQXOHVSOXLHVXQLTXHPHQWDXPRLVGHMXLOOHWHWSOXVLHXUVRUJDQL VDWLRQVKXPDQLWDLUHVDYDLHQWGUHQIRUFHUOHYROXPHGHVDLGHVDOLPHQWDLUHVSRXUVHFRXULUOHVSRSXOD WLRQVHQSURLHjODIDPLQH'LOOH\HWDO,OIDXWUHPDUTXHUTXHODILQGHODVDLVRQGHVSOXLHVHVW XQHSpULRGHG¶LQWHQVHVDFWLYLWpVSRXUOHGpPDUUDJHGHODFXOWXUHGXVRUJKRGHFRQWUHVDLVRQ,OHVW VHPpHQSpSLQLqUHHQMXLOOHWSRXUrWUHUHSLTXpHQRFWREUHVXUOHVWHUUHVDUJLOHXVHVYpULWDEOHVUpVHUYRLUV G¶HDX/RUVTXHODILQGHODVDLVRQGHVSOXLHVHVWSUpFRFHOHVSDUFHOOHVQ¶DWWHLJQHQWSDVOHXURSWLPXP GHUHFKDUJHHWOHGpYHORSSHPHQWGHVSpSLQLqUHVHVWOHQW/HVIRUWHVSOXLHVSHQGDQWFHWWHSpULRGHUHSUp VHQWHQWpJDOHPHQWXQHPHQDFHSRXUFHVSpSLQLqUHVVRXYHQWSHUGXHVGDQVOHVRUDJHV ϮϯͲŽĐƚ ϭϮͲĚĠĐ ϯϭͲũĂŶǀ ϮϭͲŵĂƌƐ ϭϬͲŵĂŝ ϮϵͲũƵŝŶ ϭϴͲĂŽƸƚ ϭϵϰϴ ϭϵϱϯ ϭϵϱϴ ϭϵϲϯ ϭϵϲϴ ϭϵϳϯ ϭϵϳϴ ϭϵϴϯ ϭϵϴϴ ϭϵϵϯ ϭϵϵϴ ϮϬϬϯ ϮϬϬϴ ϮϬϭϯ 0DURXD ĠďƵƚĚĞůĂƐĂŝƐŽŶ ĂƚĞƉƌĞŵŝğƌĞƉůƵŝĞ

(12)

'HVSDXVHVSOXYLRPpWULTXHVGHSOXVHQSOXVORQJXHVHWQRPEUHXVHV

/RUVTXHODVDLVRQGHVSOXLHVGpPDUUHODUpFXUUHQFHGHSDXVHVSOXYLRPpWULTXHVHVWXQGDQJHU SRXU OHV SODQWHV FXOWLYpHV (Q PR\HQQH FKDTXH VDLVRQ SOXYLHXVH FRQQDvW HQWUH TXDWUH HW FLQT Vp TXHQFHVVqFKHV(QIRQFWLRQGHODVLWXDWLRQDXGpEXWDXPLOLHXRXjODILQGHODVDLVRQHWDXVVLGHOHXU ORQJXHXUO¶LPSDFWVXUOHVUHQGHPHQWVHVWYDULDEOH/HVWURXVSOXYLRPpWULTXHVVLWXpVDXGpEXWGXFD OHQGULHU DJULFROH F¶HVWjGLUH DX OHQGHPDLQ GHV VHPLV UHWDUGHQW OH GpPDUUDJH GH OD FURLVVDQFH GHV SODQWHV&RQIURQWpHVjXQVWUHVVK\GULTXHORUVTX¶HOOHVVRQWHQFRUHWUqVMHXQHVOHVFpUpDOHVFXOWLYpHVDX VDKHOVRQWIUDJLOLVpHV/HVIHXLOOHVSHUGHQWODFRXOHXUYHUWHHWOHXUVFDSDFLWpVGHSKRWRV\QWKqVHVRQW DPRLQGULHV/HVSDUDVLWHVVHUpSDQGHQWHWSOXVGHODPRLWLpGHVSUpYLVLRQVGHUpFROWHVSHXWrWUHSHUGXH /RUVTXHOHVVpTXHQFHVVqFKHVLQWHUYLHQQHQWjO¶pSLDLVRQOHVFRQVpTXHQFHVSHXYHQWHQFRUHrWUHSOXV FDWDVWURSKLTXHV(QHIIHWjOHXUVIRUPDWLRQVOHVJUDLQHVGHPDwVHWPrPHGHPLOVRQWFRQVWLWXpHVj SOXVGHG¶HDX/HPDQTXHG¶HDXHVWjO¶RULJLQHGHO¶DEVHQFHGHIRUPDWLRQGHVpSLV/HVSODQWHV OHVSOXVUpVLVWDQFHSUpVHQWHQWGHVpSLVQXV/DILJXUHSUpVHQWHODGLVWULEXWLRQGHVFRXUWHVMRXUV HWGHVORQJXHVMRXUVSDXVHVSOXYLRPpWULTXHVDX[VWDWLRQVGH<DJRXDHW0DURXDSRXUOHVPRLV GHMXLQMXLOOHWHWDRW Figure 8.

Répartition moyenne des séquences sèches entre les mois de juin, juillet et août dans les stations de Yagoua et Maroua

2Q UHPDUTXH XQH SOXV IRUWH RFFXUUHQFH GHV VpTXHQFHV VqFKHV DX GpEXW GH OD VDLVRQ GHV SOXLHV QRWDPPHQWHQMXLQ$XPRLVGHMXLOOHWODPR\HQQHQ¶HVWSDVWUqVVXSpULHXUHj2QUHPDUTXHDXVVL XQHSUpGRPLQDQFHGHVFRXUWHVSDXVHV6LOHPLOHWOHVRUJKRSUpVHQWHQWXQHFHUWDLQHUpVLVWDQFHjFHV FRXUWHVSDXVHVOHPDwVUpDJLWWUqVQpJDWLYHPHQW/HVSDXVHVGHSOXVGHVHSWMRXUVUDOORQJHQWODGXUpH GXF\FOHYpJpWDWLIGHWRXWHVFHVFpUpDOHVHWOHVUHQGHPHQWVV¶HQWURXYHQWGUDVWLTXHPHQWGLPLQXpV /¶pYROXWLRQLQWHUDQQXHOOHGXQRPEUHGHVpTXHQFHVVqFKHVODLVVHYRLUXQHIRUWHYDULDELOLWp&HU WDLQHVDQQpHVFXPXOHQWSOXVGXGRXEOHGHODPR\HQQHWDQGLVTXHG¶DXWUHVHQUHJLVWUHQWVHXOHPHQWGHX[ VpTXHQFHVVqFKHV%HDXFRXSVRQWDXVVLOHVDQQpHVTXLSUpVHQWHQWXQHVLWXDWLRQPR\HQQH¬ODVWDWLRQ GH0DURXDO¶DQQpHSUpVHQWHXQUHFRUGGHSDXVHVSOXYLRPpWULTXHV/HVDQQpHVHW QHSUpVHQWHQWTX¶XQHVHXOHVpTXHQFHVqFKH/¶DQQpHSUpVHQWHpJDOHPHQWOHQRPEUHOHSOXVpOHYp GHVpTXHQFHVVqFKHVSRXUOHVGRQQpHVGH<DJRXD'¶DXWUHVDQQpHVFRPPHHW SUpVHQWHQWFKDFXQHXQHGL]DLQHGHWURXVSOXYLRPpWULTXHV/DILJXUHSUpVHQWHO¶pYROXWLRQGXQRPEUH GHVpTXHQFHVVqFKHVDQSRXUFHTXLHVWGHVVWDWLRQVGH0DURXDHW<DJRXD -XLQ -XLOOHW $RW <DJRXD &RXUWH /RQJXH 7RWDO

(13)

Figure 9. Évolution interannuelle des séquences sèches aux stations de Yagoua et Maroua

/HVFRXUEHVSUpVHQWHQWXQHWHQGDQFHjO¶DXJPHQWDWLRQGXQRPEUHDQQXHOGHVpTXHQFHVVqFKHV &HWWHUHFUXGHVFHQFHGHVWURXVSOXYLRPpWULTXHVDWWULEXDEOHDXSKpQRPqQHGHFKDQJHPHQWVFOLPDWLTXHV UHSUpVHQWHXQHPHQDFHFHUWDLQHSRXUO¶DJULFXOWXUHVDKpOLHQQH /HVFODVVHVSOXYLRPpWULTXHVHWOHVH[FqVSOXYLRPpWULTXHV /¶DQDO\VHGHVGRQQpHVGHSOXYLRPpWULHVMRXUQDOLqUHVODLVVHYRLUXQHIRUWHRFFXUUHQFHGHIDLEOHV SOXLHV/DILJXUHSUpVHQWHOHVRFFXUUHQFHVGHVpYqQHPHQWVSOXYLHX[HQIRQFWLRQGHVFODVVHV2Q FRPSWHGHVRFFXUUHQFHVGHIDLEOHVSOXLHVGHVRFFXUUHQFHVGHSOXLHVPR\HQQHVHWGHV RFFXUUHQFHVGHIRUWHVSOXLHV! Figure 10.

Occurrence des classes de pluviométriques aux stations de Maroua et Yagoua

/HVWUDFpVGHVGLIIpUHQWHVFRXUEHVPRQWUHQWXQHSUpGRPLQDQFHGHVpYqQHPHQWVGHIDLEOHVSOXYLR PpWULHVRFFXUUHQFHVHQPR\HQQHj0DURXDHWRFFXUUHQFHVHQPR\HQQHj<DJRXD,OV¶DJLWGH SUqV GH OD PRLWLp GX FXPXO GHV RFFXUUHQFHV GHV GLIIpUHQWHV FODVVHV GH SOXYLRPpWULHV /D FODVVH PR\HQQHUHSUpVHQWHGHVRFFXUUHQFHVHWODFODVVHGHVSOXLHV!PPHQKQHUHSUpVHQWHTXH GHVRFFXUUHQFHV Ϭ Ϯ ϰ ϲ ϴ ϭϬ ϭϵ ϰϴ ϭϵ ϱϬ ϭϵ ϱϮ ϭϵ ϱϰ ϭϵ ϱϲ ϭϵ ϱϴ ϭϵ ϲϬ ϭϵ ϲϮ ϭϵ ϲϰ ϭϵ ϲϯ ϭϵ ϲϴ ϭϵ ϳϬ ϭϵ ϳϮ ϭϵ ϳϰ ϭϵ ϳϲ ϭϵ ϳϴ ϭϵ ϴϬ ϭϵ ϴϮ ϭϵ ϴϰ ϭϵ ϴϲ ϭϵ ϴϴ ϭϵ ϵϬ ϭϵ ϵϮ ϭϵ ϵϰ ϭϵ ϵϲ ϭϵ ϵϴ ϮϬ ϬϬ ϮϬ ϬϮ ϮϬ Ϭϰ ϮϬ Ϭϲ ϮϬ Ϭϴ ϮϬ ϭϬ ϮϬ ϭϮ 0DURXD Ϭ Ϯ ϰ ϲ ϴ ϭϬ ϭϮ ϭϵ ϰϴ ϭϵ ϱϬ ϭϵ ϱϮ ϭϵ ϱϰ ϭϵ ϱϲ ϭϵ ϱϴ ϭϵ ϲϬ ϭϵ ϲϮ ϭϵ ϲϰ ϭϵ ϲϲ ϭϵ ϲϴ ϭϵ ϳϬ ϭϵ ϳϮ ϭϵ ϳϰ ϭϵ ϳϲ ϭϵ ϳϴ ϭϵ ϴϬ ϭϵ ϴϮ ϭϵ ϴϰ ϭϵ ϴϲ ϭϵ ϴϴ ϭϵ ϵϬ ϭϵ ϵϮ ϭϵ ϵϰ ϭϵ ϵϲ ϭϵ ϵϴ ϮϬ ϬϬ ϮϬ ϬϮ ϮϬ Ϭϰ ϮϬ Ϭϲ ϮϬ Ϭϴ ϮϬ ϭϬ ϮϬ ϭϮ <DJRXD 0DURXD <DJRXD

(14)

/¶pWXGHGHO¶pYROXWLRQLQWHUDQQXHOOHGHFHVGLIIpUHQWHVFODVVHVSOXYLRPpWULTXHVODLVVHYRLUXQHLP SRUWDQWHEDLVVHGHO¶RFFXUUHQFHGHVIDLEOHVSOXLHV/HVGRQQpHVGHODVWDWLRQGH<DJRXDSUpVHQWHQWXQH PR\HQQHDQQXHOOHGHRFFXUUHQFHVVXUODSUHPLqUHPRLWLpGHODVpULHVWDWLVWLTXHFRQWUH VHXOHPHQWRFFXUUHQFHVSRXUODGHX[LqPHPRLWLpVRLWXQHEDLVVHGH/DVLWXDWLRQ HVWHQFRUHSOXVFRQWUDVWpHjODVWDWLRQGH0DURXD6XUODSUHPLqUHPRLWLpGHODVpULHVWDWLVWLTXHRQ HQUHJLVWUHRFFXUUHQFHVPR\HQQHVGHVpYqQHPHQWVGHIDLEOHVSOXLHVFRQWUHVHXOHPHQWVXUODVH FRQGHPRLWLp,OV¶DJLWG¶XQHEDLVVHGH 3RXUFHTXLHVWGHVFODVVHVGHSOXLHVPR\HQQHVHWGHIRUWHVSOXLHVXQHFHUWDLQHVWDELOLWpHVWREVHUYpH 8QHOpJqUHDXJPHQWDWLRQHVWREVHUYDEOHSRXUFHTXLFRQFHUQHOHVIRUWHVSOXLHVQRWDPPHQWSRXUFHTXL HVWGHODVWDWLRQGH0DURXD&HVDQDO\VHVSHUPHWWHQWGHUHPDUTXHUTXHODEDLVVHGHODSOXYLRPpWULHHQ PLOLHXVRXGDQRVDKpOLHQDX&DPHURXQHVWH[FOXVLYHPHQWDEVRUEpHSDUOHVpYqQHPHQWVGHIDLEOHSOXLH /HVIRUWHVSOXLHVVHUHQIRUFHQWHWSUpVHQWHQWXQHSOXVJUDQGHFDSDFLWpG¶pURVLRQ0¶%LDQGRXQHWDO ,OIDXWHQRXWUHUHPDUTXHUTXHOHVVROVGHOD]RQHVRQWPDMRULWDLUHPHQWIUDJLOHV%UDEDQWHW *DYDXG 'LVFXVVLRQ /HVIOXFWXDWLRQVTXHFRQQDLVVHQWOHVSUpFLSLWDWLRQVGDQVOD]RQHVRXGDQRVDKpOLHQQHGX&DPHURXQ V¶LQVFULYHQW GDQV OD JUDQGH G\QDPLTXH DWWULEXDEOH DX[ FKDQJHPHQWV FOLPDWLTXHV /HV UDSSRUWV GX *,(&QRWDPPHQWOHTXDWULqPHUDSSRUWSXEOLpHQSUpVHQWHQWFHWWH]RQHFRPPHXQHGHVSOXV YXOQpUDEOHVDX[HIIHWVGXUpFKDXIIHPHQWGHO¶DWPRVSKqUHWHUUHVWUH,OV¶DJLWG¶XQH]RQHPDUTXpHSDU XQHFKDOHXUFRQVWDQWHOLpHjVDVLWXDWLRQHQPLOLHXWURSLFDOVHPLDULGHHWDXYRLVLQDJHGXGpVHUWGX 6DKDUD'HQRPEUHX[DXWHXUV6LWFKHWDO=HQJUHVVRUWHQWODFLUFXODWLRQRFpDQLTXHHW OHVPpFDQLVPHVELRJpRSK\VLTXHVLQWHUQHVFRPPHSULQFLSDX[IDFWHXUVGHG\QDPLTXHSOXYLRPpWULTXH GXVDKHODIULFDLQ /DUpSRQVHGHVSRSXODWLRQVjODEDLVVHGHODSOXYLRPpWULHHWVDGLVWULEXWLRQDOpDWRLUHSDUO¶LQWHQVL ILFDWLRQGHO¶DJULFXOWXUHGHFRQWUHVDLVRQVHSUpVHQWHQWFRPPHXQHLPSRUWDQWHPHVXUHG¶DGDSWDWLRQ FRPPXQDXWDLUHSRXUIDLUHIDFHjODPHQDFHGHO¶LQVpFXULWpDOLPHQWDLUH&HWWHSUDWLTXHHVWpJDOHPHQW XQHUpSRQVHjO¶DXJPHQWDWLRQVDQVFHVVHFURLVVDQWHGHODGHPDQGHGXHjODIRUWHSRXVVpHGpPRJUD SKLTXH/HVRUJKRGHFRQWUHVDLVRQV¶LOOXVWUHDXVVLFRPPHXQHFXOWXUHVLPSOHDYHFSHXG¶H[LJHQFHV DJURQRPLTXHV%RXFODQWVRQF\FOHYpJpWDWLIDXF°XUGHODVDLVRQVqFKHLOUpSRQGDX[EHVRLQVDOLPHQ WDLUHVGHVSRSXODWLRQVHWHQWUHDXVVLGDQVODSUpSDUDWLRQGHVERLVVRQVORFDOHbil bil(QGpSLWGXUHWRXU GHO¶KXPLGLWpDYHFGHVFRQGLWLRQVGHSOXVHQSOXVIDYRUDEOHVjO¶DJULFXOWXUHSOXYLDOHOHVFXOWXUHVGH ODSpULRGHVqFKHFRQWLQXHQWOHXUVSURJUHVVLRQVDYHFO¶DXJPHQWDWLRQGHVVXSHUILFLHV'HORQJXHVVpULHV GHGRQQpHVVXUODSURGXFWLRQDJULFROHGDQVFHWWHUpJLRQVHUDLHQWOHVELHQYHQXHVSRXUDIILQHUOHVpWXGHV DYHFGHVFDOFXOVGHFRUUpODWLRQV

/¶LQVWDELOLWp GX GpEXW GH ODVDLVRQGHV SOXLHVDYHF GH IDX[ GpSDUWV DSSHOOH jODUHGpILQLWLRQ GX FDOHQGULHUDJULFROHGDQVOD]RQH/RUVTXHSOXVG¶XQPRLVV¶pFRXOHHQWUHODSUHPLqUHSOXLHHWOHGpEXW HIIHFWLIGHODVDLVRQGHVSOXLHVOHVSRSXODWLRQVRQWEHVRLQG¶HQFDGUHPHQWSRXUQHSDVFpGHUjODPLVH HQWHUUHVSUpFRFHVGHVVHPHQFHV)DFHjO¶RFFXUUHQFHGHVVpTXHQFHVVqFKHVHWODILQSUpFRFHGHVVDL VRQVGHSOXLHLOHVWQpFHVVDLUHGHIDYRULVHUODGLIIXVLRQGHVVHPHQFHVUpVLVWDQWHVSDUODGLPLQXWLRQGHV FRWVGHVLQWUDQWVHWODIRUPDWLRQGHVSD\VDQVDX[SUDWLTXHVFXOWXUDOHVFRUUHVSRQGDQWHV6DUUHWDO 'HSOXVHQSOXVOHVSRSXODWLRQVIRQWJHUPHUOHXUVSpSLQLqUHVGHFXOWXUHVGHFRQWUHVDLVRQVVRXV OHVDUEUHVSRXUpYLWHUOHVHIIHWVGpYDVWDWHXUVGHVIRUWHVSOXLHVTXLLQWHUYLHQQHQWSDUIRLVjODILQGHOD VDLVRQGHVSOXLHV&HVIRUWHVSOXLHVDFFURLVVHQWODFDSDFLWppURVLYHGHVpFRXOHPHQWVGHVXUIDFHO¶LP SDFWGLPLQXDQWGHOD]RQHGHVPRQWV0DQGDUDYHUVODSODLQH1RPEUHXVHVVRQWOHVWHFKQLTXHVPDLWUL VpHVSDUOHVSRSXODWLRQVSRXUIDLUHIDFHLOV¶DJLWGHVGLJXHWWHVDQWLpURVLYHVOHVWHUUDVVHV1¶'MDID 

(15)

&RQFOXVLRQ &HWWHpWXGHDSHUPLVGHSUpVHQWHUOHVGLIIpUHQWVULVTXHVSOXYLRPpWULTXHVTXLLPSDFWHQWO¶DFWLYLWp DJULFROHGDQVOD]RQHVRXGDQRVDKpOLHQQHGX&DPHURXQ3DUGLIIpUHQWHVDQDO\VHVVXUOHVDEDWVSOXYLR PpWULTXHVMRXUQDOLHUVGHVVWDWLRQVGH0DURXDHW<DJRXDSOXVLHXUVUpDOLWpVOLpHVjO¶pYR OXWLRQMRXUQDOLqUHPHQVXHOOHLQWHUDQQXHOOHHWGpFDGDLUHRQWpWpPLVHVHQH[HUJXHDYHFOHXUVLPSDFWV UHVSHFWLIVVXUO¶DFWLYLWpDJULFROH(QRXWUHXQHUHYXHGHODOLWWpUDWXUHJULVHGHVUDSSRUWVHWGHVSXEOL FDWLRQVVFLHQWLILTXHVVXUOHVXMHWHWFRQFHUQDQWOD]RQHG¶pWXGHRQWSHUPLVGHFRQWH[WXDOLVHUOHVUpVXO WDWVHWGHOHVGLVFXWHU/DVLWXDWLRQDFWXHOOHGHPDQGHG¶DYDQWDJHVG¶pWXGHVSRXUpFODLUFLUODVLWXDWLRQ FOLPDWLTXHGHOD]RQHVRXGDQRVDKpOLHQQHGX&DPHURXQ/¶LQGLVSRQLELOLWpGHVGRQQpHVRXOHXUVFD UDFWqUHVSDUFHOODLUHVH[LJHQWOHUHFRXUVjG¶DXWUHVVRXUFHVQRWDPPHQWOHVREVHUYDWLRQVVDWHOOLWDLUHV /HVGpILVFRPPHODGpJUDGDWLRQGHO¶HQYLURQQHPHQWHQJpQpUDOODSUHVVLRQGpPRJUDSKLTXHOHVSUR EOqPHVOLpVjO¶LQVpFXULWpH[LJHQWGHJUDQGVSURMHWVYLVDQWODGLPLQXWLRQGHODYXOQpUDELOLWpGHVSD\VDQV DX[DOpDVFOLPDWLTXHVO¶XUJHQFHpWDQWG¶pORLJQHUOHVSHFWUHGHODIDLPTXLFRQVWLWXHXQHPHQDFHSHU PDQHQWHGDQVOD]RQH 5pIpUHQFHVELEOLRJUDSKLTXHV

$*5+<0(7Le Sahel face aux changements climatiques : Enjeux pour un développement durable%XOOHWLQ 0HQVXHO1XPpURVSpFLDOS

$QRXJXH7RQIDFN%)%HWJXLUR1JZDLER)+DLZH%51ZRZH:DQIHR7FKRNROYD3HW:DGDL'

Rapport de l’étude sur la vulnérabilité des communes de la région de l’extrême nord aux effets du changement climatique0DURXDS

%UDEDQW 3 HW *DYDXG 0 Les sols et les ressources en terre du Nord Cameroun 3DULV<DRXQGp 256 7200(65(6,5$1RWLFH([SOLFDWLYHQS

%8&5(3Troisième Recensement Général de la Population et de l’Habitat (RGPH)UDSSRUWGHSUpVHQWDWLRQGHV UpVXOWDWVGpILQLWLIVS

'LOOH\0HW%RXGUHDX7(&RPLQJWRWHUPVZLWKYXOQHUDELOLW\DFULWLTXHRIIRRGVHFXULW\GHILQLWLRQ Food

Policy 

(USLFXP0%LQDUG03HWHUV-3HW$OH[DQGUH-8QHPpWKRGHG¶DQDO\VHGHVFDUDFWpULVWLTXHVGHODVDLVRQ GHVSOXLHVHQUpJLRQVDKpOLHQQH([HPSOHVSULVDX6pQpJDOLQ(USLFXP0HGActes des Journées de

Climato-logie0RQW5LJL%HOJLTXHQRYHPEUH/LqJH3UHVVHV8QLYHUVLWDLUHVGH/LqJH

)$2Climate Change and Food Security : a Framework for Action5RPH'RFXPHQWWREHSXEOLVKHGDW WKH%DOL&RQIHUHQFH

)RWVLQJ(Un Système d’Information pour l’analyse intégrée des changements d’utilisation de l’espace à

l’Ex-trême-Nord du Cameroun7KqVHGH'RFWRUDWGHO¶8QLYHUVLWpGH<DRXQGp,6%1S

)RWVLQJ(&KH\ODQ-3:RXWHU7'H*URRWHW9HUEXUJ3+Un dispositif multi-échelle d’analyse des

dynamiques agraires en zone des savanes de l’Extrême nord du Cameroun. qPHV5HQFRQWUHVGH7KpR4XDQW

)pYULHUS

)RWVLQJ(HW0DLQDP)'\QDPLTXHGXVRUJKRGHFRQWUHVDLVRQHWSRWHQWLDOLWHVGHVVROVHQ]RQHGHVDYDQHGH O¶([WUrPH1RUGGX&DPHURXQ,Q-HDQ<YHV-DPLQ/6HLQ\%RXNDU&KULVWLDQ)ORUHWCirad – PrasacS

*,(&Bilan 2007 des changements climatiques. Contribution des Groupes de travail I, II et III au quatrième

Rapport d’évaluation du Groupe d’experts intergouvernemental sur l’évolution du climat>eTXLSHGHUpGDFWLRQ

SULQFLSDOH3DFKDXUL5.HW5HLVLQJHU$*,(&*HQqYH6XLVVHSDJHVKWWSZZZPLQDGHUFPXSORDGV +XEHUW3&DUERQQHO-3HW&KDRXFKH$. 6HJPHQWDWLRQGHVVpULHVK\GURPpWpRURORJLTXHV$SSOLFDWLRQjGHV

VpULHVGHSUpFLSLWDWLRQVHWGHGpELWVGHO¶$IULTXHGHO¶2XHVWJournal of HydrologyS

+XOPH0&OLPDWLFSHUVSHFWLYHVRQ6DKHOLDQGHVLFFDWLRQ. Global and Environmental Change ,16Annuaire statistique du Cameroun. Recueil des séries d’informations statistiques sur les activités

écono-miques, sociales, politiques et culturelles du pays jusqu’en 2013S

(16)

-DQLFRW6HW)RQWDLQH%/¶pYROXWLRQGHVLGpHVVXUODYDULDELOLWpLQWHUDQQXHOOHUpFHQWHGHVSUpFLSLWDWLRQVHQ $IULTXHGHO¶2XHVWLa MétéorologieVpULH /H%DUEp//HEHO7DQG7DSVRED'5DLQIDOOYDULDELOLW\LQ:HVW$IULFDGXULQJWKH\HDUVJournal of Climate /HEHO7 $OL$5HFHQWWUHQGVLQWKH&HQWUDODQG:HVWHUQ6DKHOUDLQIDOOUHJLPHJournal of HydrologyGRLMMK\GURO /LHQRX*6LJKRPQRX'6LJKD1NDPGMRX/0DKH*(NRGHFN*(HW7FKRXD)6\VWqPHK\GUROR JLTXHGX<DpUp([WUrPH1RUG&DPHURXQFKDQJHPHQWVFOLPDWLTXHVHWDFWLRQVDQWKURSLTXHVFRQVpTXHQFHVVXU OHELODQGHVWUDQVIHUWVVXSHUILFLHOV Hydrology of the Mediterranean and Semiarid RegionsProceedings of an

international symposiumKHOGDO0RQWSHOOLHU$SULO,$+63XEOQR

/XEqV1LHO+0DVVRQ-03DWXUHO-(HW6HUYDWe9DULDELOLWpFOLPDWLTXHHWVWDWLVWLTXHVeWXGHSDUVL PXODWLRQGHODSXLVVDQFHHWGHODUREXVWHVVHGHTXHOTXHVWHVWVXWLOLVpVSRXUYpULILHUO¶KRPRJpQpLWpGHFKURQLTXHV

Revue des Sciences de l’Eau,YROQS'2,DU

0¶%LDQGRXQ0*XLEHUW+HW2OLQD-3). &DUDFWpULVDWLRQGXFOLPDWGDQVTXDWUHWHUURLUVHQUpJLRQVRXGDQR VDKpOLHQQHGX1RUG&DPHURXQHWFRQVpTXHQFHVSRXUO¶DJULFXOWXUH-HDQ<YHV-DPLQ/DPLQH6HLQ\%RXNDU&KULV WLDQ)ORUHWCirad – Prasac,SKDO!

1¶'MDID2+Rapport synthèse de l’enquête générale sur les itinéraires d’adaptation des populations locales

à la variabilité et aux changements climatiques conduite par AGRHYMET et l’UQAM1LDPH\SDJHV

2]HU3%RGDUW&HW7\FKRQ%$QDO\VHFOLPDWLTXHGHODUpJLRQGH*RXUp1LJHURULHQWDOUpFHQWHVPRGLIL FDWLRQVHWLPSDFWVHQYLURQQHPHQWDX[Cybergeo : European Journal of Geography >(QOLJQH@(QYLURQQHPHQW 1DWXUH3D\VDJHGRFXPHQWPLVHQOLJQHOHPDLFRQVXOWpOHPDL85/KWWSZZZF\EHU JHRUHYXHVRUJ'2,F\EHUJHR

2]HU3(USLFXP0'HPDUpH*HW9DQGLHSHQEHHFN07KH6DKHOLDQGURXJKWPD\KDYHHQGHGGXULQJWKH VHydrological Sciences Journal

3LpUL&Fertilité des terres de savane. Bilan de trente ans de recherche et de développement agricoles au sud

du Sahara0LQLVWqUHGHOD&RRSpUDWLRQ&LUDG,UDW3DULVS

6DUU%7UDRUp6HW6DODFN6Évaluation de l’incidence des changements climatiques sur les rendements

des cultures céréalières en Afrique soudano-sahélienne.&HQWUH5pJLRQDO$*5+<0(7&,/661LDPH\

6LWFK66PLWK%3UHQWLFH,&$UQHWK$%RQGHDX$&UDPHU:.DSODQ-/HYLV6/XFKW:6\NHV 07KRQLFNH.DQG9HQHYVN\6(YDOXDWLRQRIHFRV\VWHPG\QDPLFVSODQWJHRJUDSK\DQGWHUUHVWULDO FDUERQF\FOLQJLQWKH/3-'\QDPLF*OREDO9HJHWDWLRQ0RGHOGlobal Change Biol

6LYDNXPDU09.3UHGLFWLQJUDLQ\VHDVRQSRWHQWLDOIURPWKHRQVHWRIUDLQVLQ6RXWKHUQ6DKHOLDQDQG6XGDQLDQ FOLPDWLF]RQHVRI:HVW$IULFDAgricultural and Forest Meteorology

6XOWDQ%$OKDVVDQH$%DUELHU%%DURQ&%HOOD0HGMR7VRJR0%HUJ$'LQJNXKQ0)RUWLOXV- .RXUHVV\0/HEORLV$0DUWHDX50XOOHU%2HWWOL34XLULRQ35RXGLHU36H\GRX%7UDRUp HW9DNVPDQQ0/DTXHVWLRQGHODYXOQpUDELOLWpHWGHO¶DGDSWDWLRQGHO¶DJULFXOWXUHVDKpOLHQQHDXFOLPDW DXVHLQGXSURJUDPPH$00$La Météorologie – Spécial AMMA±RFWREUH

<RXQJ(0DQG0RWWUDP0$Transplanting sorghum and pearl millet as a means of increasing food

secu-rity in semi-arid low income countries,ILQDOWHFKQLFDOUHSRUW$YDLODEOHRQOLQHDWKWWSZZZIDRRUJGRFVHLPVXS

ORDGDJURWHFKU

=HQJ11HHOLQ-'/DX.0DQG7XFNHU&-(QKDQFHPHQWRILQWHUGHFDGDOFOLPDWHYDULDELOLW\LQWKH 6DKHOE\YHJHWDWLRQLQWHUDFWLRQScience