An existing United Kingdom–funded water project, located in the Usangu Plains of Tanzania, aims to understand the causes for dry season zero flows in the previously perennially flowing Great Ruaha River, which drains from the Usangu wetland. Studies reveal that the common explanation of competition for water between wetlands and irrigation alone is insufficient to explain reduced flows. Instead, complex biological and hydrological processes influence the allocation of water between wetlands and irrigation. This article outlines these processes and proposes some hypotheses: (a) Certain types of rice irrigation development may not be detrimental to the Usangu wetlands; (b) the sustainability of rice irrigation and wetlands can be supported by recognizing their dynamic nature; (c) the concept of efficiency of irrigation in areas with a semiarid climate should be treated with caution. The studies will assist in the sustainable management of water for both environmental and developmental needs.
Get full access to this article
View all access options for this article.
References
1.
Barbier, E. B., & Thompson, J. R. (1998). The value of water: Floodplain versus large-scale irrigation benefits in northern Nigeria. Ambio, 27(6), 434-440.
2.
Behnke, R. H., Jr., & Scoones, I. (1993). Rethinking range ecology: Implications for rangeland management in Africa. In R. H. Behnke, Jr., I. Scoones, & C. Kerven (Eds.), Range ecology at disequilibrium: New models of natural variability and pastoral adaptation in African savannas (pp. 1-30). London: ODI, IIED, and Commonwealth Secretariat.
3.
Biswas, A. K., Hartvelt, F., & Tortajada Quiroz, C. (Eds.). (1996). Capacity building for integrated water management [Special issue]. Water Resources Development, 12(4), 397-514.
4.
Burke, J. J., Jones, M. J., & Kasimona, V. (1994). Approaches to integrated water resource development and management of the Kafue basin, Zambia. In C. Kirby & W. R. White (Eds.), Integrated river basin development (pp. 407-423). Chichester, UK: Wiley.
5.
Carter, R. C. (1998). Prospects for sustainable water management policy in sub-Saharan Africa, with special reference to the northeast arid zone of Nigeria. In D. K. Vajpeyi (Ed.), Water resource management: A comparative perspective (pp. 107-127). New York: Praeger.
6.
Charnley, S. (1994). Cattle, commons, and culture: The political ecology of environmental change on Tanzanian rangeland. Unpublished doctoral dissertation.
7.
Clark, M. J., & Gardiner, J. L. (1994). Strategies for handling uncertainty in integrated river basin planning. In C. Kirby & W. R. White (Eds.), Integrated river basin development(pp. 437-445). Chichester, UK: Wiley.
8.
Danida. (1998). Smallholder irrigation improvement. Agricultural sector programme support (Project preparation report). Dar es Salaam, Tanzania: Rufiji Basin Water Office, Ministry of Water, Energy and Minerals.
9.
Danida/World Bank. (1995). Water resources management in the Great Ruaha basin: A study of demand-driven management of land and water resources with local level participation. Dar es Salaam, Tanzania: Rufiji Basin Water Office, Ministry of Water, Energy and Minerals.
10.
European Commission. (1998). Guidelines for water resources development co-operation: Towards sustainable water resources management, a strategic approach. Brussels, Belgium: Author.
11.
Guerra, L. C., Bhuiyan, S. I., Tuong, T. P., & Barker, R. (1998). Producing more rice with less water (SWIM Paper No. 5). Colombo, Sri Lanka: International Irrigation Management Institute.
12.
Hazelwood, A., & Livingstone, I. (1978). The development potential of the Usangu plains of Tanzania. London: The Commonwealth Secretariat, Commonwealth Fund for Technical Cooperation.
13.
Hollis, G. E., & Acreman, M. C. (1994). The functions of wetlands within integrated river basin development: International perspectives. In C. Kirby & W. R. White (Eds.), Integrated river basin development (pp. 351-365). Chichester, UK: Wiley.
14.
HTS Ltd, Water Management Consultants, Local Perspectives Ltd. (1999). Inception report: Sustainable management of the Usangu wetlands and their catchments. Tanzania: Author.
15.
Keller, A., Keller, J., & Seckler, D. (1996). Integrated water resource systems: Theory and policy implications (Research Report No. 3). Colombo, Sri Lanka: International Irrigation Management Institute.
16.
Kikula, I. S., Charnley, S., & Yanda, P. (1996). Ecological changes in the Usangu Plains and their implications on the downstream flow of the Great Ruaha river in Tanzania. Tanzania: University of Dar es Salaam, Institute of Resource Assessment.
17.
Maltby, E. (1986). Waterlogged wealth: Why waste the world's wet places. London: Earthscan.
18.
Masija, E. H. (1993). Irrigation of wetlands in Tanzania. In G. L. Kamukala & S. A. Crafter (Eds.), Wetlands of Tanzania: Proceedings of a seminar on wetlands of Tanzania (pp. 73-83). Cambridge, UK: IUCN.
19.
Mitchell, B. (Ed.). (1990). Integrated water management: International experiences and perspectives. London: Belhaven.
20.
Mitsch, W. J., & Gosselink, J. G. (1993). Wetlands (2nd ed.). New York: Van Nostrand Reinhold.
21.
Newson, M. (1997). Land, water, and development: Sustainable management of river basin systems (2nd ed.). London: Routledge.
22.
Postel, S. (1992). The last oasis: Facing water scarcity. London: Earthscan.
23.
Scoones, I. (1991). Wetlands in drylands: The agroecology of Savanna systems in Africa. Part 1: Overview—ecological, economic, and social issues. London: International Institute for Environment and Development.
24.
Seckler, D. (1996). The new era of water resources management: From “dry” to “wet” water savings (Research Report No. 1). Colombo, Sri Lanka: International Irrigation Management Institute.
25.
Sharma, N. P., Damhaug, T., Gilgan-Hunt, E., Grey, D., Okaru, V., & Rothberg, D. (1996). African water resources: Challenges and opportunities for sustainable development (World Bank Technical Paper No. 331. Africa Technical Department Series). Washington DC: World Bank.
