Conclusions

Figure 14 shows the basin groups where water is abundant and those with a risk of water scarcity, if the whole potential is developed. Once again, it should be stressed that in the figures each major basin group was considered as one entity, while in reality water may be scarce only in part of the basin. For example, in the Niger basin, few problems will exist in the Benue tributary basin, but problems may arise in the main Niger River region straddling Mali and Niger. For the Indian Ocean Coast, problems may arise in the basins shared between Swaziland, South Africa and Mozambique, but not in the basins that are located entirely within South Africa. on the other hand, for the Zambezi basin as a whole no water problems exist according to the figures, but in the upper part, occupied by the Chobe tributary basin which is shared between Angola, Namibia, Zambia and Botswana, water problems may arise. Details are given in Chapter 6.

Figure 15 presents the distribution of the 42.5 million hectares of irrigation potential over the different basins. Figures for the basins in arid areas have to be considered as upper limits from the point of view of water availability, while for some humid basins, where neither water nor land is a limiting factor, other factors (mostly economic) have been taken into account.

TABLE 91 Irrigation potential by country and by basin in hectares

Basin	Senegal	Niger	Lake Chad	Nile	Rift	Sheb-Juba	Congo/Zaire	Zambezi	Okavango	Limpopo	Orange	South. Int.	North. Int.	Med. Coast	N.W. Coast	W. Coast	W.C. Coast	S.W. Coast	S.A. Coast	I.O. Coast	E.C. Coast	N.E. Coast	Madagascar	Islands	Total for country
Country	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)	(12)	(13)	(14)	(15)	(16)	(17)	(18)	(19)	(20)	(21)	(22)	(23)	(24)
Algeria		0	0										125200	385100	0										510300
Angola							900000	700000	200000			50000					50000	1800000							3700000
Benin		100000														200000									300000
Botswana								1080	6060	5000	0	2500													14640
Burkina Faso		5000														159460									164460
Burundi				80000			105000																		185000
Cameroon		20000	100000				50000										120000								290000
Cape Verde																								2990	2990
Central African Rep.			500000				1400000																		1900000
Chad		0	835000										0												825000
Comoros																								300	300
Congo							255000										85000								340000
Côte d'Ivoire		50000														425000									475000
Djibouti					450																	550			1000
Egypt				4420000									0	0								0			4420000
Equatorial. Guinea																	30000								30000
Eritrea				150000	0																	37500			187500
Ethiopia				2220000	790000	627300																0			3637300
Gabon																	440000								440000
Gambia																80000									80000
Ghana																1900000									1900000
Guinea	5000	185000														330000									520000
Guinea Bissau																281290									281290
Kenya				180000	52500	9460															111100				353060
Lesotho											12500														12500
Liberia																600000									600000
Libya													0	40000											40000
Madagascar																							1500000		1500000
Malawi								160900													1000				161900
Mali	10000	556000											0			0									566000
Mauritania	165000												0		0										165000
Mauritius																								20000	20000
Morocco + W. Sahara													60000	380000	1200000										1640000
Mozambique								1700000		148000										368000	856000				3072000
Namibia								11000	2000		25000	400						7900	1000						47300
Niger		222000	48000										0												270000
Nigeria		1678510	502000													50000	100000								2330510
Rwanda				150000			9000																		159000
Sao Tome & Principle.																								10700	10700
Senegal	240000															100000									340000
Seychelles																								1000	1000
Sierra Leone																807000									807000
Somalia						230000															0	10000			240000
South Africa										131500	352500								83200	877800					1445000
Sudan			4000	2750000	0								0									30000			2784000
Swaziland																				93220					93220
Tanzania				30000	1060		0	0													959360				990420
Togo																180000									180000
Tunisia													40000	523000											563000
Uganda				202000	0																				202000
Zaire				10000			6980000										10000								7000000
Zambia							101000	422000																	523000
Zimbabwe								165400		10900		1100								211000					388400
Sum of country (C)	420000	2816510	1989000	10192000	844010	866760	9800000	3160380	208060	295400	390000	54000	225200	1328100	1200000	5112750	835000	1807900	84200	1550020	1927460	78050	1500000	34990	46719790
Total for basin (B)	420000	2816510	1163200	8000000	844010	351460	9800000	3160380	208060	295400	390000	54000	71000	850000	1200000	5112750	835000	1807900	84200	1550020	1927460	78050	1500000	34990	42504370
Difference: (C) - (B)	0	0	825800	2192000	0	515300	0	0	0	0	0	0	154200	478100	0	0	0	0	0	50020	0	0	0	0	4215420
Basin as % countries	100%	100%	58%	78%	100%	41%	100%	100%	100%	100%	100%	100%	32%	64%	100%	100%	100%	100%	100%	97%	100%	100%	100%	100%	91%

In Figure 16 irrigation potential is expressed in hectares per km² of basin area (or in percentage of basin area). The figure clearly shows that irrigation potential is less in the arid northern, northeastern and southern regions than in the rest of the continent.

Table 92 compares the soil and terrain suitability figures at basin level with the irrigation potential figures obtained from the literature review. For the continent as a whole, 42.5 million hectares correspond to only 7% of the area with soil and terrain suitable for irrigation (almost 600 million hectares). The basins with the highest percentages are the humid ones, where water is not a limiting factor, and those located in areas with high population densities (Figure 17) and where population pressure leads to a need for maximum agricultural development. Analysing the figures at basic unit level, the part of Egypt lying in the Nile basin is the only area in the whole continent where land is the real limiting factor and where marginal soils have been included in the irrigation potential figure.

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