Identifying Water Crossings in Rural Liberia and Rwanda Using Remote and Field-Based Methods

Safe and consistent access to essential services is critical for poverty alleviation in rural communities, but even significant physical transportation barriers, such as pedestrian water crossings, are poorly mapped, leaving the scope of need for rural trailbridges largely unknown. Field-based efforts to catalogue those barriers can be effective but are costly and time-consuming. The study described here details field-based methods for identifying pedestrian water crossings in rural Liberia and Rwanda, as well as remote methods, to evaluate their effectiveness and potential application for assessing future rural infrastructure networks. The work highlights challenges, addresses components of the field-based method that limit scalability on a global level, and outlines a way forward for future endeavors to identify pedestrian water crossings. Overall, the most effective remote method applied in this study identified 16 percent of the crossings identified using field-based methods in the same area of interest in Liberia, and 72 percent of the crossings identified using field-based methods in the same area of interest in Rwanda. The field-based method remains the most effective method for bridge site identification, though the significant resources required for an effective field study underscore the need for greater investment in remote methods. Additionally, as neither method alone yields results that fully encapsulate bridge need, the authors recommend a blended approach that incorporates a more sophisticated remote method with streamlined field-based methods that leverage existing local knowledge and expertise.