Mapping and understanding farmers’ responses to gully-induced problems in the Abaya-Chamo Sub-Basin, Southern Ethiopia
Gully erosion threatens the livelihoods of rural farmers by causing direct cropland loss and reducing agricultural productivity. In the Shafe catchment of southern Ethiopia, smallholder farmers facing severe food insecurity have implemented gully interventions (GIs) to counter this land degradation. Yet the spatial distribution of these GIs remains highly uneven. This study investigates which GIs have been implemented, what drives their adoption, and whether this adoption has spread as a diffusion process over time.
To investigate GI adoption, fieldwork was conducted across two rural administrative units in the Shafe catchment. GI presence was mapped for 751 gullies based on field observations and drone surveys. Additionally, a household survey of 178 farmers was conducted, providing socio-economic and perceptual data of the farmers, their plots and their gullies. Variables were tested through univariate screening and logistic regression models. Finally, spatial clustering and spatio-temporal modelling were used to investigate the adoption of GIs over time.
Results indicate that GIs in the Shafe catchment are dominated by loose rock check dams and banana plantations. Conservation and economic motivations drive farmers to combine these interventions, since they promote gully stabilisation through sediment infilling while simultaneously creating additional agricultural opportunities on the gully floor. Field observations identified at least one GI in 18% of mapped gullies, with treated gullies being larger and located closer to roads and settlements.
The household survey, capturing individual farmer decisions across multiple gullies, suggests 48% of farmer-reported gullies have been treated at some point. Farmers across the study area share a broadly similar subsistence-oriented profile. With 88% of the farmers having implemented at least one GI somewhere on their land, motivation is near-universal. The central question is therefore not who adopts, but where: farmers preferentially treat gullies that are accessible, on productive plots close to the homestead, exclusively owned, and perceived as severely impacted. Adoption likelihood is slightly higher for farmers exclusively dependent on agriculture and those with sufficient economic surplus. Predictive models based on spatial variables and socio-economic variables provide a step towards a practical targeting framework.
This study also presents one of the first attempts to diffusion analysis for gully interventions. GI adoption shows significant spatial clustering. A weak but detectable diffusion effect suggesting that farmers are more likely to adopt GI when neighbouring farmers have done so in prior years, pointing to informal knowledge spreading. However, data limitations remain substantial and further research should confirm this with more complete data.
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