Assessing the impact of Soil and conservation techniques in South East Tunisia

Abstract

This paper examines the financial, economic and social feasibility of the investments in soil and water conservation techniques and their impacts on the livelihood conditions of the local population in the Oum Zessar watershed located in south-east Tunisia. The study uses Integrated Impact assessment framework, based on two main approaches: Extended Cost-Benefit Analysis (ECBA) to internalise environmental externalities and Sustainable Livelihoods Approach (SLA). Results show that coupling the two methods is useful to upscale impact assessment from field level to regional level and to cover the impacts on different rural household capitals (human, financial, physical, natural and social) influencing well-being of the local population. The analysis for 30 years period found that, despite environmental externalities in the form of increased flood damage, investments in water harvesting techniques are beneficial at private and social levels for the local population. The financial analysis show that these investments are highly beneficial with 30 years IRR of 24% and a positive NPV of 3615 TD/ha at 10% discount rate. The economic analysis using market prices and accounting for subsidies, the investment becomes even more interesting with a NPV of 4283 TD/ha (discount rate of 10%) and an IRR of 27%, which is a clear improvement compared to the financial analysis. These results are robustly positive at a high discount rate of 12% (NPV of 2073 DT/ha) and reduced benefits when considered some negative environmental effects such as higher flood damage due to failure of Jessours (NPV of 1333 DT/ha and IRR of 20%). Besides the financial and economic benefits, the impacts of the soil and water conservation techniques in had clear and positive impacts on the livelihoods of the local population. Recommendations for a more integrated policy approach to watershed management are provided.