This study aimed at quantitative analysis of morphometric parameters of Agula watershed and its subwatersheds using remote sensing data, geographic information system, and statistical methods. Morphometric parameters were evaluated from four perspectives: drainage network, watershed geometry, drainage texture, and relief characteristics. A sixth-order river drains Agula watershed and the drainage network is mainly dendritic type. The mean bifurcation ratio (R b ) was 4.46 and at sub-watershed scale, high R b values (R b [ 5) were observed which might be expected in regions of steeply sloping terrain. The longest flow path of Agula watershed is 48.5 km, with knickpoints along the main river which could be attributed to change of lithology and major faults which are common along the rift escarpments. The watershed has elongated shape suggesting low peak flows for longer duration and hence easier flood management. The drainage texture analysis revealed fine drainage which implies the dominance of impermeable soft rock with low resistance against erosion. High relief and steep slopes dominates, by which rough landforms (hills, breaks, and low mountains) make up 76% of the watershed. The S-shaped hypsometric curve with hypsometric integral of 0.4 suggests that Agula watershed is in equilibrium or mature stage of geomorphic evolution. At sub-watershed scale, the derived morphometric parameters were grouped into three clusters (low, moderate, and high) and considerable spatial variability was observed. The results of this study provide information on drainage morphometry that can help better understand the watershed characteristics and serve as a basis for improved planning, management, and decision making to ensure sustainable use of watershed resources.

The hilly and mountainous terrains of the highlands of Ethiopia are frequently affected by rainfall-induced landslides of different types and sizes. The major types of landslides reported to have been triggered by heavy rainfalls include debris/earth slides, debris/earth flows and, and medium to large-scale rockslides. Though rockfalls are common in the Ethiopian highlands no association is made with rainfalls. Review of the previous studies revealed that landslide hazards have been causing: loss of human lives, failure of engineering structures, damage on agricultural lands and on the natural environment. Medium to large-scale rockslides were reported in areas underlain by Paleozoic glacial sediments and volcanic rocks. Evaluation of the relationship between landslides and various influencing factors show that the debris/earth slides/flows have prevailed in: (a) areas which are underlain by Paleozoic glacial sediments, shales, and basalt flows, (b) hillslopes characterized by slope angles in the range 15-45 degrees, (c) terrains represented by concave shapes with some on planar surfaces, (d) areas affected by active gully erosion/artificial excavations, and (e) places represented by sparse or no vegetation cover with deeper roots. With regard to the triggering mechanisms, most of the rainfall-induced landslides have taken place in the late periods of the rainy seasons (late August to early September) following heavy rainfalls indicating that process is related to raise in groundwater level coupled with a certain intensity of rainfall event. Ethiopia is currently involved in massive infrastructural development (including roads and railways), urban development and extensive natural resources management. In this whole socio-economic development, landslides and landslide-generated ground failures need to be given due attention in order to reduce losses from such hazards and create safe geoenvironment.

Mapping soil erosion hotspots and assessing the potential impacts of land management practices in the highlands of Ethiopia The International Center for Tropical Agriculture (CIAT) believes that open access contributes to its mission of reducing hunger and poverty, and improving human nutrition in the tropics through research aimed at increasing the eco-efficiency of agriculture. CIAT is committed to creating and sharing knowledge and information openly and globally. We do this through collaborative research as well as through the open sharing of our data, tools, and publications.

To tackle the problem of soil erosion and moisture stress, the government of Ethiopia introduced a yearly mass campaign where communities get together and implement various soil and water conservation (SWC) and water harvesting (WH) practices. Although the interventions are believed to have reduced soil erosion/sediment yield and enhanced surface and ground water, quantitative information on the impacts of various options at different scales is scarce. The objective of this study was to assess the impacts different land uses, SWC and WH interventions on water and suspended sediment yield (SSY) at plot and watershed scales in the central highlands of Ethiopia. Standard erosion plot experiments and hydrological stations were used to monitor the daily water and SSY during 2014 to 2017. The results show differences between treatments both at plot and watershed scales. Runoff and soil loss were reduced by an average 27 and 37%, respectively due to SWC practices at the plot level. Overall, SWC practices implemented at the watershed level reduced sediment yield by about 74% (in the year 2014), although the magnitude of sediment reduction due to the SWC interventions reduced over time. At both scales it was observed that as the number of years since SWC measures have been in place increased, their effectiveness declined due to the lack of maintenance. This study also revealed that extrapolating of plot data to watershed scale causes over or under estimation of net erosion.

Improvements in land use and management are needed at a global scale to tackle interconnected global challenges of population growth, poverty, migration, climate change, biodiversity loss, and degrading land and water resources. There are hundreds of technical options for improving the sustainability of land management and preventing or reversing degradation, but there are many sociocultural, institutional, economic, and policy barriers hindering their adoption at large scale. To tackle this challenge, the Dryland Systems Program of the Consultative Group for International Agricultural Research and the UN Convention to Combat Desertification convened an expert group to consider barriers and incentives to scaling technologies, processes, policies, or institutional arrangements. The group reviewed existing frameworks for scaling sustainable land management (SLM) interventions across a range of contexts and identified eight critical actions for success: (a) plan iteratively; (b) consistently fund; (c) select SLM options for scaling based on best available evidence; (d) identify and engage with stakeholders at all scales; (e) build capacity for scaling; (f) foster institutional leadership and policy change to support scaling; (g) achieve early benefits and incentives for as many stakeholders as possible; and (h) monitor, evaluate, and communicate. Incentives for scaling were identified for the private sector, farmers and their communities, and policy makers. Based on these findings, a new action framework for scaling is presented that analyses the contexts where specific SLM interventions can be scaled, so that SLM options can be screened and adapted to these contexts, piloted and disseminated. The framework can help countries achieve land degradation neutrality.