Vulnerability of household livelihoods to climate variability and change in the central rift valley sub-basin of Ethiopia.

Ethiopia, despite contributing minimally to global greenhouse gas emissions, is consistently cited as one of the most vulnerable countries, not only in Sub-Saharan Africa regions but also globally, to climate variability and change. The country's farming households are most vulnerable because of their climate-sensitive livelihoods and limited resources to finance adaptation measures. This study aimed to assess the livelihood vulnerability of communities reliant on a mixed crop-livestock agricultural system and natural resources in the Central Rift Valley sub-basin of Ethiopia to climate variability and change. Structured interviews were used to collect quantitative data from 339 randomly selected households. Livelihood Vulnerability Index was developed to assess the degree of livelihood vulnerability between the two districts. The survey results were supported and substantiated by focus group discussions. The findings show that farm households living in the sub-basin experience different levels of vulnerability to climate variability and change because of their varying adaptive capacities. Considering the aggregate Livelihood Vulnerability Index, Arsi Negele district is considered to be more vulnerable to climate variability and change. The livelihood Vulnerability Index-Intergovernmental Panel on Climate Change results also show that Arsi Negele is more vulnerable since its exposure scores exceed its adaptive capacity. Several factors contribute to the weak adaptive capacity of farmers in Arsi Negele. These factors include lesser adoption of agricultural technology, a low level of knowledge and education, insufficient social networks, less diversification of livelihood strategies, and higher socio-demographic vulnerability. In contrast, Adami Tullu Jido Kombolcha district has a higher sensitivity score due to its limited access to potable water, housing, and land ownership. Strategies that minimize households' degree of sensitivity and enhance their adaptive capacity should be promoted. Such strategies should include the adoption of improved agricultural technologies, strengthening awareness and technical capacity, promoting better soil and water management, accessing credit options, and building community networks. Diversifying household income and establishing alternative livelihoods should also be encouraged.

Impact of adoption of climate-smart agriculture on food security in the tropical moist montane ecosystem: The case of Geshy watershed, Southwest Ethiopia.

The traditional rain-fed agriculture system of Ethiopia is suffering from climate change impacts and extremes. It must be improved to feed the growing population and create a resilient society. Climate-smart agriculture (CSA) is currently promoted as an approach intended to increase sustainable agricultural productivity, enhance household resilience, and reduce greenhouse gas emissions. This study was, therefore, undertaken to examine how food security can be improved by the adoption of multiple climate-smart agriculture (CSA) practices of smallholder farmers in a moist tropical montane ecosystem of Southwest Ethiopia. Data was collected from 384 purposively selected households through cross-sectional study design using a semi-structured questionnaire. Eight Focus group discussions and fifteen key informant interviews were also conducted to check the reliability of the survey data collected. In the study area, a total of eighteen CSA practices, adopted by farmers, were identified. Using principal component analysis, these practices were further grouped into five packages and a multinomial endogenous switching regression model was used to link these packages to the food security status. The findings revealed a great variation in the proportion of households using CSA practices where 92.3 % were using crop management practices whereas 11.2 % were using soil and water conservation practices. The study found that the maximum effect of CSA adoption on food security was by farmers who adopted all the five category CSA technologies. Households that adopted this package were more food secure by 41.2 % in terms of per capita annual food expenditure, 39.8% in terms of Household Food Insecurity Access Scale (HFIAS), and 12.1% in terms of Household Food Consumption Score (HFCS) than the non-adopters. The adoption of this group of practices was further influenced positively by farm size, gender, and productive farm asset values. Using CSA practices in combinations and to a relatively larger extent can potentially solve food security problems. Motivating farmers by providing income-generating activities and discouraging land fragmentation through public education is essential. This in turn improves CSA adoption and initiates production assets investment that can absorb climate change risks.

Performance evaluation of multiple regional climate models to simulate rainfall in the Central Rift Valley Lakes Basin of Ethiopia and their selection criteria for the best climate model.

The historical datasets of five regional climate models (RCMs) available in the Coordinated Regional Downscaling Experiment (CORDEX)-Africa database are evaluated against ground-based observed rainfall in the Central Rift Valley Lakes Basin of Ethiopia. The evaluation is aimed at determining how well the RCMs reproduce monthly, seasonal, and annual cycles of rainfall and quantify the uncertainty between the RCMs in downscaling the same global climate model outputs. Root mean square, bias, and correlation coefficient are used to evaluate the ability of the RCM output. The multicriteria decision method of compromise programming was used to choose the best climate models for the climate condition of the Central Rift Valley Lakes subbasin. The Rossby Center Regional Atmospheric Model (RCA4) has downscaled ten global climate models (GCMs) and reproduces the monthly rainfall with a complex spatial distribution of bias and root mean square errors. The monthly bias varies in the range of - 35.8 to 189%. The summer (wet), spring, winter (dry), and annual rainfall varied within the range of 1.44 to 23.66%, - 7.08 to 20.04%, - 7.35 to 57%, and - 3.11 to 16.5%, respectively. To find the source of uncertainty, the same GCMs but downscaled by different RCMs were analyzed. The test results showed that each RCM differently downscaled the same GCM, and there was no single RCM model that consistently simulated the climate conditions over the stations in the study regions. However, the evaluation finds reasonable model skill in representing the temporal cycles of rainfall and suggests the use of RCMs where climate data is scarce after bias correction.

Spatiotemporal trends in mean and extreme climate variables over 1981-2020 in Meki watershed of central rift valley basin, Ethiopia.

Understanding the spatiotemporal changes of climate extremes is essential for managing climatic risk. In the present study, trends of annual and seasonal climate variables along with extreme temperature and precipitation were examined in eight climatic stations of Meki watershed, the Central Rift Valley Basin, Ethiopia during the period 1981 to 2020. A set of 20 precipitation and temperature extreme indices were selected and computed in RClimDex package of the R program to detect climate extreme events. The recent method of Innovative trend analysis, the non-parametric Mann-Kendall trend test, and Sen's slope estimator were applied to evaluate trends of the annual and seasonal precipitation and temperature. The result indicates that the annual precipitation has been decreasing in 71% of climatic stations and 43% of these stations showed a significant trend. The annual minimum temperature declined in 75% of the stations, whereas all stations indicated a significant increasing trend in annual mean maximum temperature. The Mann-Kendall test detected a significant increasing and decreasing trend in most of the temperature and precipitation extreme indices respectively. For the temperature extremes, more frequent warm and fewer cold temperature extremes were observed. In more than 75% of the climatic stations, a considerable drying trend was found for the precipitation extreme indices. Besides, stations with significant warming and drying trends were located in the downstream areas of the watershed. Overall, this study proved that the observed warming trend in mean annual temperature contributed to changes in the normal thresholds of extremes. The change in precipitation and temperature extremes have increased the frequency, intensity, and duration of extreme events in most of the stations. Likewise, climate extreme events that occur more frequently with high intensity are likely to exacerbate climatic risks, which require proper planning of risk management strategies in Meki watershed.

Evaluating the Effectiveness of Best Management Practices On Soil Erosion Reduction Using the SWAT Model: for the Case of Gumara Watershed, Abbay (Upper Blue Nile) Basin.

This study was conducted to evaluate the effectiveness of best management practices (BMPs) to reduce soil erosion in Gumara watershed of the Abbay (Upper Blue Nile) Basin using the Soil and Water Assessment Tool (SWAT) model. The model was calibrated (1995-2002) and validated (2003-2007) using the SWAT-CUP based on observed streamflow and sediment yield data at the watershed outlet. The study evaluated four individual BMP Scenarios; namely, filter strips (FS), stone/soil bunds (SSB), grassed waterways (GW) and reforestation of croplands (RC), and three blended BMP Scenarios, which combines individual BMPS of FS and RC (FS & RC), GW and RC (GW & RC), and SSB and GW (SSB & GW). Mean annual sediment yield at the baseline conditions was estimated at 19.7 t ha-1yr-1, which was reduced by 13.7, 30.5, 16.2 and 25.9% in the FS, SSB, GW, and RC Scenarios, respectively at the watershed scale. The highest reduction efficiency of 34% was achieved through the implementations of the SSB & GW Scenario. The GW & RC, and FS & RC Scenarios reduced the baseline sediment yield by 32% and 29.9%, respectively. The study therefore concluded that the combined Scenarios mainly SSB & GW, and GW & RC can be applied to reduce the high soil erosion in the Gumera watershed, and similar agro-ecological watersheds in Ethiopia. In cases where applying the combined scenarios is not possible, the SSB Scenario can yield significant soil erosion reduction.

Smallholder farmers' livelihood vulnerability to climate change-induced hazards: agroecology-based comparative analysis in Northcentral Ethiopia (Woleka Sub-basin).

BACKGROUND: Due to its climate-sensitive agricultural system and low adaptive capacity of the subsistence farmers, Ethiopia is cited among the countries experiencing frequent drought and highly vulnerable to climate change associated impacts. Micro level vulnerability assessment, in the context of a changing climate, has a paramount significance in designing policies addressing climate change induced effects. Assessing vulnerability to climate change is important for defining the risks posed by the change and it provides a starting point for the determination of effective means of promoting remedial actions to minimize impacts by supporting coping strategies and facilitating adaptation options targeted at specific context. METHODS: We employed cross-sectional survey research design has to examine the extent of livelihood vulnerability of 384 randomly selected smallholder farmers from three agroecologies which was supplemented by interviews. Livelihood vulnerability index, using integrated indicator approaches and principal component analysis, has been used. Chi-square test, F-test and t-test were used to examine association and mean differences among three agroecologies and between cropping types in terms of different attributes. FINDINGS: Overall, smallholder farmers living in kolla agroecology were found to be the most vulnerable to climate change induced hazards followed by dega. In terms of type of cropping season, belg dominated areas were relatively more vulnerable than those residing in meher dominated areas. Different biophysical and socio-economic attributes contributed their own role both for exposure, sensitivity and adaptive capacity differences among smallholder farmers farming in different agroecologies and different types of cropping seasons. CONCLUSION: We recommend that interventions undertaken to lessen the impact of climate change should be targeted to the factors which contribute to high extent of sensitivity and for those which could enhance the adaptive capacity of smallholder farmers. Specifically, we suggest that resilience-building adaptation interventions like expansion of small-scale irrigation, accessing of microfinance service, early warning and timely information, extension support, non-farm sources of income, training and skill development, expansion of infrastructure have to be promoted thereby increase the adaptive capacity of subsistence rainfed-dependent farmers to withstand the vagaries of the climate variability risk. Moreover, disparities in the same agroecology have to be addressed properly in livelihood vulnerability discourse.

Evaluating potential impacts of land management practices on soil erosion in the Gilgel Abay watershed, upper Blue Nile basin.

Assessing the potential impacts of different land management practices helps to identify and implement sustainable watershed management measures. This study aims to assess a change in soil erosion rate under different land management practices in the Gilgel Abay watershed of the upper Blue Nile basin, Ethiopia. The Revised Universal Soil Loss Equation (RUSLE) model that was adapted to the Ethiopian highlands context was employed to estimate the rate of soil erosion. The impact of land management practices on soil erosion was estimated for three scenarios, which were baseline, intensive cultivation, and extensive cultivation scenarios. At the baseline scenario, the mean annual soil erosion was estimated at ~32.8 t ha-1yr-1, which is equivalent to a loss of ~13.66 Mt yr-1 from the entire watershed. While the rate of soil erosion reduced to ~11.3 t ha-1yr-1 during the implementation of intensive cultivation management practice, which reduced the total soil loss in the watershed by 65%. On the other hand, under the extensive cultivation scenario, the mean annual soil erosion rate increased to ~34.4 t ha-1yr-1. The findings suggest that implementing agricultural intensification management practices can significantly reduce soil erosion in the watershed.

Spatiotemporal Analysis of Land-use and Land-cover Dynamics of Adama District, Ethiopia and Its Implication to Greenhouse Gas Emissions.

Uncontrolled change in land use and land cover (LULC) enhances the concentrations of greenhouse gases in the atmosphere. This study, therefore, is aimed at the spatiotemporal analysis of LULC dynamics and their implications for the greenhouse gas emissions of the Adama district of Ethiopia. The dry season Landsat image Thematic Mapper (TM) of 1986, Enhanced Thematic Mapper (ETM) of 2000, and Enhanced Thematic Mapper Plus (ETM+ ) of 2014 were downloaded from the United States Geological Survey Global Visualization Viewer Website and employed. The hybrid classification approach was performed after the preprocessing of the image. Moreover, observations, key informant interviews, and focus group discussions were used. The analysis was carried out using the image data and survey data. The result indicates that agricultural land and shrub and bush lands covered 80.98%, 76.75%, and 74.42% of the study area during 1986, 2000, and 2014, respectively. Although there were differences in the magnitudes and rates of change during the considered years, the LULC classification results of this study indicated that most natural environments are converted to human-dominated environments, which can be attributed to human-induced activities. Due to this conversion, environmental degradation is aggravated, which again paves the way for the increased concentration of greenhouse gases in the atmosphere. The study concludes that, largely as a result of interventions from the communities living in the area, the study area is being transformed from the natural ecosystem to a managed environment. Hence, the practices of smallholder farmers with respect to protected areas, afforestation, and reforestation must be strengthened and supported by an integrated policy framework. Integr Environ Assess Manag 2019;00:1-13. © 2019 SETAC.

A synoptic land change assessment of Ethiopia's Rainfed Agricultural Area for evidence-based agricultural ecosystem management.

This paper demonstrates synoptic ways of presenting and characterizing land change processes across Ethiopia's large, complex Rainfed Agricultural Area (RAA). We translated pixel-level detected changes into neighbourhood-level changes that are useful to decision-makers. First, we identified pixel-level changes without and with type/direction of change, based on land cover maps from the years 1986 and 2010. For type-/direction-based characterization, we sorted observed transitions into four categories of prominent land change processes ("forest degradation", "deforestation", "afforestation", and "no change"). Adopting appropriate window sizes for identified ecoregions in the study area, we ran a focal statistics summation operator separately on the two change rasters (with/without consideration of direction of change). The results obtained by applying the approach can be described in relative terms as well as qualitative terms, using ranges of change values that can be further classified using qualitative terms, i.e. ranging from "no change" to "high/substantial change". Our non-directional change assessment result showed that approximately 6% of the RAA is characterized by substantial change, whereas 40% appears stable ("no change"). Based on the directional-change assessment results, 3% of deforestation, 4% of forest degradation, and 3% of revegetation processes were found to constitute "high/substantial change". The types and intensity of landscape transformations display distinct spatial patterns linked to agro-ecological belts and socio-economic dynamics. Minimal reverse changes were observed on some severely degraded lands in the highlands, but the overall per cent cover remains relatively small. Overall, vegetation degradation still exceeds regeneration by more than half a per cent. Relatively lower altitudes and middle altitudes exhibit higher transformation. The presented approach and resulting outputs can provide planners and decision-makers with a synoptic view of land change processes. It can support policy formulation of sustainable land management and rehabilitation activities of the agricultural ecosystem at national and regional scales.

Temporal Dynamics of the Driving Factors of Urban Landscape Change of Addis Ababa During the Past Three Decades.

Mapping and quantifying urban landscape dynamics and the underlying driving factors are crucial for devising appropriate policies, especially in cities of developing countries where the change is rapid. This study analyzed three decades (1984-2014) of land use land cover change of Addis Ababa using Landsat imagery and examined the underlying factors and their temporal dynamics through expert interview using Analytic Hierarchy Process (AHP). Classification results revealed that urban area increased by 50%, while agricultural land and forest decreased by 34 and 16%, respectively. The driving factors operated differently during the pre and post-1991 period. The year 1991 was chosen because it marked government change in the country resulting in policy change. Policy had the highest influence during the pre-1991 period. Land use change in this period was associated with the housing sector as policies and institutional setups were permissive to this sector. Population growth and in-migration were also important factors. Economic factors played significant role in the post-1991 period. The fact that urban land has a market value, the growth of private investment, and the speculated property market were among the economic factors. Policy reforms since 2003 were also influential to the change. Others such as accessibility, demography, and neighborhood factors were a response to economic factors. All the above-mentioned factors had vital role in shaping the urban pattern of the city. These findings can help planners and policymakers to better understand the dynamic relationship of urban land use and the driving factors to better manage the city.