Virtual water trade in Tanzania

Characterised by an arid and semi-arid environment, Tanzania is one of the countries stressed by an increasing water scarcity. This thesis addresses the issue of water scarcity by looking for ways of alleviating it through virtual water trade strategy across agro-ecological zones within the country. The goal was to examine virtual water trade as policy option for water resources management in Tanzania. To attain this goal, the specific objectives were to quantify crop water requirement for maize and rice in different agro-ecological zone in Tanzania and to quantify the volume of virtual water flows between agro-ecological zones in the period of 2001 to 2011. This study employed CROPWAT model to quantify crop water requirement of these two cereal crops in Tanzania. And excel to quantify virtual water flow. Results indicate that crop water requirements were location specific owing to the marked variability in the agro-ecological characteristics of the study zone. Maize had been found to have the lowest amount, probably because of this crop’s relatively short growing period as compared to paddy (rice). Market analysis indicated that Central zone is a leading exporter of water. On Contrary, virtual water data analysis indicated that southern highlands is a leading net exporter of water (33x109 mVyr'1) as compared to other zones such as northern highlands (2xl09 m3/yr[), Southern Coast (8xl09 mVyr'1), Western Zone (lOxlO9 nrVyr'1), Eastern Zone (26xl09 mVyr'1), Lake Zone (21xl09 m3/yr_1) and Central Zone (6xl09 m3/yr_1). The information obtained from this analysis will enhance understanding of crop water requirements, consequently helping to improve the productivity of these two crops. Further, the information will add value on issues of water resources management.