Virtual water trade in the semi-arid regions of Nigeria

Abstract With continuous growth in the world population, the demand for water increases and hence water scarcity rises. Adequate measures have to be put in place in order to make proper utilization of the available water. Virtual water trade is defined as the water volume conveyed within the imported or exported food. Hence, the aim of this study was to determine the virtual water volume required for crops production of 25 different crops in the semi-arid regions of Nigeria for the year 2013. In addition, the water footprint, imports and exports of virtual water, the production volume of virtual water, green, blue, and grey water contributions to crops production, water balance, exports income, imports costs and value of the selected crops produced were distinguished. The study was conducted using CROPWAT 8.0 software. The result revealed that in the 7 regions of the semi-arid zone, the crops selected had total volume of virtual water produced of approximately 35.9 Gm3/yr, exports volume of virtual water was 27.5 Mm3/yr, imports volume of virtual water was 8.6 Gm3/yr, water footprint was 44.5 Gm3/yr and water balance was 8.6 Gm3/y. Total value of the produced crops was $2.6 billion, export income $1.1 million and import cost $794.6 million. Gusau with higher percentage of green water used is preferable region to grow crops in the semi-arid regions of Nigeria, which can consequently lead to reduced cost of production and scarcity of water.