WETLAND AGRICULTURAL PRODUCTION AND RIVER BASIN DEVELOPMENT IN THE HADEJIA-JAMA ARE VALLEY, NIGERIA

There are relatively few studies of the values associated with tropical wetlands. Lack of such knowledge is a significant contributor to the failure of river basin planning to take account of existing economic activities such as indigenous irrigation, herding or fishing. Development of formal projects such as dams and large-scale irrigation schemes can have serious adverse effects on existing activities and economic values in wetlands. Data on these values are vital if development planning is to take them into account properly. This paper describes the nature and magnitude of agricultural production in the floodplain wetland of the Hadejia-Jama'are rivers in northern Nigeria, between Hadejia and Gashua. There is flood-rice and rainfed agriculture in the wet season, and in the dry season cropping by residual soil moisture, shadoof and (expanding rapidly through the 1980s) small petrol pumps. Most of this production is dependent on the annual flood. This has been reduced in magnitude by drought, and by dam construction and water abstraction for irrigation upstream in Kano State. The gross value of agricultural production is large, somewhere between 250 and 850 million Naira (1989 prices). The economic importance of the floodplain is placed in the context of the performance of the costly formal large-scale irrigation schemes upstream which have been favoured by the river basin planning process.