干旱区生态环境知识资源中心

This paper aims at assessing the impact of water pricing policy on the sustainability of irrigated farming systems and the preservation of water and soil resources in Tunisia. The bio-economic modelling approach coupling the biophysical model CropSyst (Cropping System Model) and the economic farm model FSSIM (Farming System Simulator) has been mobilized for this impact analysis. This approach was applied to four farm types representing irrigated agriculture systems in the Oum Zessar watershed located in the south-east of Tunisia. The main results from this research show: the strong dependence of different agricultural systems on the pricing water policy; the high sensitivity of farms in the private irrigated schemes to the progressive increase of irrigation water cost compared to those in the public scheme, which are able to reduce the impact of water cost increase thanks to their good adaptation capacity. The agricultural systems of groundwater wells seem more fragile and unsustainable, and thus, the extension of public schemes would be preferable for maintaining irrigated activities and ensuring natural resources sustainability in these arid zones.