In this paper, we show two methods for estimating future water demands in the Zambezi River basin that are driven by population end economic growth. We compare the future population sizes estimated by these methods, as well as their potential effects on water demand. These are the UN population estimates and those forecast by the International Futures modelling system. The potential differences between the methods are of concern because, depending on which view is taken, substantial differences in investment could result, with potentially large different socio-economic outcomes. The methods of estimation are spelt out in a little more detail below and the  essential differences between the methods are discussed.


Chapman, A. 2012. Socio-Economic Futures of the Zambezi River Basin. OneWorld Sustainable Investments. For the Climate and Development Knowledge Network (CDKN); and the World Bank.  Available: