Scenario-based robustness analysis of optimized I.D.E.-Style treadle pump designs

Poverty affects hundreds of millions of people globally. Marketbased strategies can help alleviate poverty in developing countries by encouraging entrepreneurial activity and have the potential to be more effective than traditional approaches, such as development aid from countries or non-governmental organizations. Development organizations often target the agricultural sector because of the prevalence of subsistence and small-scale farming, particularly in rural regions of developing countries. Improving the reliability of irrigation techniques can help farmers expand out of primarily subsistence farming and begin to sell a portion of their crop, thus achieving the objectives of market-based poverty alleviation. Human-powered pumps are a popular tool used in irrigation because they require low capital cost and negligible operating cost. Previous work provided a model for finding Pareto-optimal IDE-style treadle pump designs. This work utilizes that model to produce a dense set of Pareto-optimal designs, and then investigates the robustness of the designs by simulating their performance in a variety of modified use scenarios. Our results show that pumps optimized for low flow rates (less than 3.0 L/s) are highly robust, particularly with respect to age-related changes in the operator's stature or mobility. In addition, these pumps can operate with nearoptimal efficiency across a variety of target flow rates and well depths. These pumps are ideal for single family use or for shared use amongst multiple families in a village. Pumps optimized for flow rates greater than 3.0 L/s are less robust with respect to changes of operator stature (experiencing decreases in flow rate of up to 60%) but may be suitable for use on farms or by service providers.