Poverty is of multidimensional characteristics affecting nearly a billion world population. Especially, a third of sub Saharans fall under poverty. The emergence of climate change coupled with the incidence of drought, are worsening the situation. The only option to escape this challenge is through the development of water resource projects. In attempting to do so, Ethiopia has yet developed not more than 5% of the irrigation potential. Much of this is owned and poorly managed by small holder farmers. The purpose of this study is thus to investigate whether small scale irrigation schemes contribute to poverty reduction or not. Based on 313 sample households from the Rift Valley Lake Basins, it was observed that irrigation improved household income and contributed to poverty reduction. However, the enhanced poverty impact of irrigation was constrained due to unsatisfactory performance and imperfect market. Thus, enhancing the capacity of water user associations through provision of training, market linkage and finance are a necessary step to improve irrigation performance towards poverty reduction.

For development of a comprehensive sediment management plan, it is crucial to categorize watersheds on the basis of soil erosion hotspot areas to extend the useful life of water bodies (e.g., Gidam reservoir). The goal of this study was to assess the surface water potential and identify erosion hotspot areas of the Gidabo watershed in Ethiopia using the Soil and Water Assessment Tool (SWAT) model. The SUFI-2 (Sequential Uncertainty Fitting Version 2) program was used to calibrate the model, and the model’s performance was evaluated. According to the catchment prioritization analysis, some of the sub-basins with similar land use, land cover, and soil type but with higher slope would generate higher sediment yield. Furthermore, the soil conservation scenarios were developed in SWAT, and the model result showed that average annual sediment yield could be reduced by the application of grassed waterway, filter strips, terracing, and contouring by 49%, 37.53%, 62.32%, and 54.6% respectively. It was concluded that sediment yield reduction by applying terracing was more effective than other conservation measures for affected sub-basins. The surface water potential of the watershed varies spatially from sub-basin to sub-basin, and the mean monthly surface water potential of the watershed is 33 million cubic meters. These findings can help decision-makers to develop appropriate strategies to minimize the erosion rate from erosion hotspot areas and to allocate the watershed water potential for different types of water demands. Strip planting, terracing, or contour farming may be necessary on chosen hotspot erosion sites to reduce the effect of slopes on surface runoff flow velocity and sediment transport capacity.

and bare land increased by 83.20 and 65.54 ha respectively while shrub & grass land and forest land decreased by 112.59 and 46.16 ha respectively. The results showed that cultivated land and settlement land expanded by 67.38% and 532% respectively whereas forest land, shrub land &grass land declined by 66.35%, 18.36% respectively over the analysis period (1972-2017). There should be appropriate rural land use/management policy by identifying proper land for specific purpose so that degraded lands would not put under cultivation.

Establishing forest plantation on degraded rangelands play a key role in forest rehabilitation processes through afforestation or/and reforestation. In-situ rainwater harvesting has positive impact on seedling survivals at degraded rangelands. A quadrant of 10 m × 10 m of five times replication at three slope classes under area enclosure was used. Both survived seedlings and soil physical parameters were collected from three soil depth profiles (0-10, 10-20 and 20-30 cm) and then analyzed. Of the transplanted seedling to the area enclosure with pits (66.53, 46.13, and 25.66%), half-moon (66.53, 41.80, and 20.40%), and soil bund embankment (55.46, 42.60, and 28.80%) were survived at bottom, middle and upper slope classes respectively. The interaction of seedling survival in both planting methods were not significantly different at P>0.05, particularly, in half-moon and pits except soil bund embankment. Because, tree seedling rose at nursery site transplanted to the embankment of structures, that is, on the dig out soils. The conserved moisture is far from seedling roots as a result needs long roots to absorb but weak and short rooting system. Pits and half-moon showed good performance than soil embankments at bottom parts. This explains that almost all in-situ structures play a crucial role at flat land rather than middle and upper parts but highest bulk density achieved for the upper parts, which might be due to risks of soil erosion and only left with very compacted cobles. Therefore, slope gradient have implication on in-situ rainwater harvesting devices efficiencies in conserving moisture for tree seedling survival so as to establish good forest stands.

The rapid growth of urbanization, industrialization and poor wastewater management practices have led to an intense water quality impediment in Lake Hawassa Watershed. This study has intended to engage the different water quality indices to categorize the suitability of the water quality of Lake Hawassa Watershed for anthropogenic uses and identify the trophic state of Lake Hawassa. Analysis of physicochemical water quality parameters at selected sites and periods was conducted throughout May 2020 to January 2021 to assess the present status of the Lake Watershed. In total, 19 monitoring sites and 21 physicochemical parameters were selected and analyzed in a laboratory. The Canadian council of ministries of the environment (CCME WQI) and weighted arithmetic (WA WQI) water quality indices have been used to cluster the water quality of Lake Hawassa Watershed and the Carlson trophic state index (TSI) has been employed to identify the trophic state of Lake Hawassa. The water quality is generally categorized as unsuitable for drinking, aquatic life and recreational purposes and it is excellent to unsuitable for irrigation depending on the sampling location and the applied indices. Specifically, in WA WQI, rivers were excellent for agricultural uses and Lake Hawassa was good for agricultural uses. However, the CCME WQI findings showed rivers were good for irrigation but lake Hawassa was marginal for agricultural use. Point sources were impaired for all envisioned purposes. The overall category of Lake Hawassa falls under a eutrophic state since the average TSI was 65.4 and the lake is phosphorous-deficient, having TN:TP of 31.1. The monitored point sources indicate that the city of Hawassa and its numerous industrial discharges are key polluters, requiring a fast and consequent set-up of an efficient wastewater infrastructure, accompanied by a rigorous monitoring of large point sources (e.g., industry, hospitals and hotels). In spite of the various efforts, the recovery of Lake Hawassa may take a long time as it is hydrologically closed. Therefore, to ensure safe drinking water supply, a central supply system according to World Health organization (WHO) standards also for the fringe inhabitants still using lake water is imperative. Introducing riparian buffer zones of vegetation and grasses can support the direct pollution alleviation measures and is helpful to reduce the dispersed pollution coming from the population using latrines. Additionally, integrating aeration systems like pumping atmospheric air into the bottom of the lake using solar energy panels or diffusers are effective mitigation measures that will improve the water quality of the lake. In parallel, the implementation and efficiency control of measures requires coordinated environmental monitoring with dedicated development targets.