Irrigation potential in Africa:
A basin approach


Table of contents


FAO LAND AND WATER BULLETIN 4

FAO Land and Water Development Division

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

M-54
ISBN 92-5-103966-6

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Information Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00100 Rome, Italy.

FAO 1997


Contents


Foreword

Acknowledgements

Chapter 1: Introduction

Chapter 2: Methodology and data used

Definition of irrigation potential
Definition of the basic units
Identification of the physical resources

Land resources
Water resources
Irrigation water requirements

Review of existing information on irrigation potential
Environmental considerations
Interpretation of the results

Chapter 3: Soil and terrain suitability for surface irrigation

General methodology

Soil requirements for irrigation
Evaluation techniques

Results

Chapter 4: Water resources

Methodology and definitions used

Potential yield
Surface water and groundwater
Internally and globally produced renewable water resources
Periods of reference
Evaporation from wetlands and lakes

Results
Breakdown of water resources by basic unit

Chapter 5: Irrigation water requirements

Methodology

Delineation of irrigation cropping pattern zones
Definition of the climate stations' area of influence
Combination of cropping pattern zones with the climate stations
Calculation of irrigation water requirements

Results

Chapter 6: Review of existing information on irrigation potential

Methodology and limitations
Results per major basin group

The Senegal River basin
The Niger River basin
The Lake Chad basin
The Nile Basin
The Rift Valley
The Shebelli - Juba basin
The Congo/Zaire River basin
The Zambezi basin
The Okavango basin
The Limpopo basin
The Orange basin
The South Interior
The North Interior
The Mediterranean coast
The North West Coast
The West Coast
The Gambia River Basin
The Volta Basin
The West Coast, excluding the Gambia River and Volta basins
The west central coast
The south west coast
The South Atlantic coast
The Indian Ocean coast
The East Central coast
The North East coast
Madagascar
Islands

Data quality assessment

Chapter 7: Environmental considerations in irrigation development

Potential environmental impacts of irrigation development

Waterlogging and salinization
Water-borne and water-related diseases
Potential environmental impacts of darns and reservoirs
Socio-economic impacts irrigation schemes
Alternatives to mitigate the negative impacts of irrigation projects

The role of wetland and the impacts of water development projects

Wetlands in the West African Sahel
The Hadejia-Nguru wetlands
Effects of the Jonglei canal on the Sudd swamps

Regional aspects of environmental impacts and 'hot spots'

The arid North African sub-region
The Sudano-sahelian Belt
Humid West Africa
The Congo/Zaire basin
East Africa
Southern Africa

Summary of environmental impact hazard related to irrigation development

Chapter 8: General results and conclusions

Physical resources

Land
Water
Irrigation water requirements (IWR)

Review of existing formation on irrigation potential
Conclusions

Chapter 9: Main sources of information

General
Africa
River basins
Countries