Traveling from villages to water sources is a critical part of life in the Omo Valley in Ethiopia. In the Murile region, there are only a few places where there is access to the Omo River, because the river is deeply incised in most places, making access difficult if not impossible. Using a Russian topographic map, first-hand knowledge of the access points to the river and village locations from a person associated with the Murulle Foundation, and a DEM of Ethiopia, we were able to map out the easiest and shortest routes from villages to water sources. Several GIS concepts were incorporated into this project including, projection, georeferencing, digitizing, reasoning, measurement and optimization. A least-cost analysis was performed to determine routes based on minimizing slope and avoiding water bodies. The results provide four maps of routes from villages to each of the four water access points along the Omo River.
Although the results maps provide an exciting end product, we must keep in mind that this is a first cut. There are many uncertainties regarding this calculation: location of villages and water access points, microtopography not captured by DEM, and other areas to avoid, such as wetlands and tributaries. Like all models and GIS analyses, these results should be ground-truthed. Also, besides physical parameters that should be captured by the model, there may be societal issues, such as tribal tensions, that could influence where trails should be made.
Finally, we realize that this project may seem to have produced obvious results to the locals that live in the Murile region. The villagers and locals know the land much better than a DEM or GIS can ever characterize it. However, this type of analyses can be useful in the case of outside agencies building trails or roads, or when arriving in an unfamiliar area.