The salt problem in Ethiopia has been further exacerbated by a number of factors, including poor water quality, ineffective on-farm water management techniques, and a lack of appropriate and technically sound drainage infrastructure at irrigation sites. Despite its importance, no systematic review or documentation of the extent and consequences of the problem has been made so far. This scientific review primarily focuses on original studies published in the country, notably in arid and semi-arid regions where salinity issues have a significant influence. The data indicated that soil and irrigation water salinity have a substantial link with crops and agricultural communities in Ethiopia. Salinity has a significant impact on soil and water fertility, resulting in poorer agricultural production, food insecurity, and poverty. Salinity has a significant impact on crops in the country, from the germination stages to the harvesting stages during the growing season. If the current state of soil and water management continues, the severity of both soil and irrigation water salinity will reach an irreversible level that significantly impedes the country’s agricultural production capacity. As a result, cultured irrigation water treatment, crop selection based on salinity and sodicity levels, irrigation water quality, leaching, and fertilizer use in combination with organic manures are scientifically proven actions to address the salinity problem. Furthermore, to adequately reclaim and manage salinity in Ethiopia’s dryland saline zone, multi-stakeholder participation is required.

The sign of climate change and its impact is revealing on different natural and synthetic systems. The objective of this study was to analyze and quantify the impacts of climate change on streamflow in Kesem sub-basin, Middle Awash River basin, Ethiopia. Ensemble mean of four Coordinated Regional Climate Downscaling Experiment (CORDEX) Africa regional climate models operating under two alternative scenarios of Representative Concentration Pathways (RCP 4.5 and RCP 8.5) was used. The period from 1975 - 2005 was used for the analysis of the baseline scenario while the periods 2050s (2020 - 2049) and 2080s (2050 - 2080) were used for future scenarios analysis. The impact assessment on streamflow was done using soil and water assessment tool (SWAT) hydrological model. The statistical performance of the SWAT model in simulating the streamflow was shown with coefficient of determination (R²) of 0.84, R-Factor of 0.56 and Nash-Sutcliffe Efficiency (NSE) of 0.78 for monthly calibration and R² of 0.78, R-Factor of 0.67 and ENS of 0.73 for monthly validation periods. Mean monthly changes in precipitation and temperature (maximum and minimum) were used to quantify these impacts. The result of bias-corrected precipitation and temperature disclosed a logical increase in all future periods for both RCP 4.5 and RCP 8.5 scenarios. These changes in climate variables created an increase in mean annual streamflow by 14.5 and 19.1 % for RCP 4.5 and by 4.7 and 6.9 % for RCP 8.5 scenarios of the 2050s and 2080s respectively. This result provides valuable information for guiding current and future water resource management in the Kesem sub-basin and similar other areas in Ethiopia.

Drought is one of the challenges in Ethiopia that affects the agricultural production. Ecosystems can mitigate the effects of climate-related hazards including drought. For this reason, nature-based solutions (NbS) are becoming more prominent to manage climate-related impacts in developing countries; however, there is still limited empirical evidence, which would inform NbS policy and practices. Thus, the aim of this study was to characterize droughts in Eastern Ethiopia (the case of Erer Sub-basin) and assess the effectiveness of various NbS for drought. The temporal changes in soil moisture deficit index (SMDI) (agricultural drought) and standard precipitation evapotranspiration index (SPEI) (meteorological drought) at various timescales (1, 3, and 6 months) between 1981 and 2020 were analyzed. Qualitative analysis was used to categorize and evaluate the effectiveness of NbS to mitigate drought risk by adopting a Living Labs approach. Overall, the study revealed that droughts showed an increasing trend with more frequency, longevity, and severity. The drought analysis results showed that SPEI’s variants were less reliable than SMDI_0–5 and SMDI_5–100. With an increase in rainfall, SPEI showed stronger relationships with SMDI_0–5 at one and two-month delays between May and July. SPEI and SMDI_5–100 performed better in terms of capturing actual drought occurrences than SMDI_0–5. The results of focus group discussions (FGD) suggested NbS such as habitat restoration, structural restoration, reforestation, rehabilitation, revegetation, land enclosures, conservancies, and locally managed areas have been practiced as a strategy to manage drought risks. Overall, the study indicated that a new, comprehensive approach through nature-based solutions to reduce the risk of drought is urgently needed.

Nowadays, the land use and land cover change and its impacts are revealing on different natural resource and man-made systems. This study attempted to examine the land use and land cover (LULC) dynamics on this using multi-spectral satellite imageries in Geographical Information System (GIS) in the Kesem sub-basin of the Awash River Basin, Ethiopia. It also attempted to assess the community perceptions on this using field observation. Three LULC maps were produced by analyzing remotely sensed images of Landsat satellite imageries within three periods of time from 1986 to 2013. Supervised image classification was used to map LULC classes and explain the drivers, and causes were linked to the changes. The result from LULC maps of 2013 showed nine major land use and land cover types. From 1986 to 2000, there were, among others, a dramatic expansion of agricultural land, massive settlement, and widespread eucalyptus plantation, all of which contributed to a dramatic decrement of shrub land and acacia in the sub-basin. The major driving forces for these changes were population density and over-use of land. The major consequences are the degradation of biodiversity, and loss of natural resources. The significant need of new and sweeping land use policy whose key tenets involve conservation and rehabilitation of land resources and appropriate land use planning is offered to policymakers.