Participatory Analysis and Management of Water and Ecosystem Services in the Upper Blue Nile Basin

Livelihoods in rural communities of the Ethiopian highlands are strongly dependent on ecosystem services (ESS). At the same time, they face many challenges and are typically characterised by extreme poverty. Little is known about the social-ecological context of ESS management, and how this impacts the livelihoods and poverty rates at a community level. Improved understanding of how local stakeholders interact with their surrounding ESS to support their livelihoods may inform more viable and realistic approaches to the sustainable use of ESS and maximize poverty alleviation. In this research, I applied a series of approaches including literature review, participatory rural appraisal (PRA), field experiments, computational modelling (particularly using hydrological and erosion models), and scenarios analysis to identify the most economic livelihood strategies to maximize poverty alleviation at the local scale, and to be environmentally sustainable. First, I studied the current relationship between livelihoods and ESS, and how they are managed for poverty alleviation in the Ethiopian highlands using a combination of scientific and grey literature review. My analysis focused on the identification of the main physical processes that lead to degrading ESS, the formal and informal decision-making processes that are used to address these threats at the community level, and their relation to various levels of external intervention. I find that the main degradation processes are soil structure degradation and soil loss, but also reductions in groundwater recharge, river base flow, and carbon storage. Yet, government policies that aim to address these issues are based on a strongly centralized approach that is insufficiently tailored to the local natural and social-economic context. This may result in some short-term benefits but has a high risk of jeopardizing long term sustainability. The review outcome highlights the need for a participatory bottom-up approach to problem framing, and data generation and exchange to promote both environmental sustainability and poverty alleviation. Following the outcome of this literature review, I develop my research methodological framework based on further review of the literature about participatory approaches to knowledge generation in the field of ecosystem services management to support sustainable development. To implement this framework, I conducted a detailed situation analysis of a representative case study (Debre Mawi watershed) in the upper Blue Nile. This watershed is exemplary for the Ethiopian and other tropical highlands where livelihood security is strongly dependent on local ESS, particularly those provided by water and soils. This situation analysis research was conducted by applying PRA including various participatory methods, such as household questionnaires, semi-structured interviews with key informants, open community meetings, and small focus group discussions. These participatory techniques were complemented with detailed field observations through transect walks with farmers and ESS mapping. This situation analysis provided insights in the problems faced by stakeholders in the study area, and yielded options for improved livelihood and environmental sustainability. Poverty lock-in challenging strategies found through this participatory rural appraisal approach are crop irrigation and livestock fattening. For both strategies and domestic use, water scarcity was found to be the primary limiting factor. Therefore the next step of this research project focused on water availability. With regard to water availability, I tested the hypothesis that groundwater and water harvesting increase water supply during the dry season for the local community using experimental data and modelling. I confirmed that soil and water conservation (SWC) interventions, which were implemented at degraded lands, are enhancing recharge by converting them into areas which actively contribute to recharge (referred throughout this thesis as “hillsides” because of their hydrological similarity to natural hillsides). I found that the area of such “hillsides” increased by 55% over a period of 4 years. The current (natural and regenerated) hillside area of Debre Mawi is 65.4% of the total catchment area; considering this area, groundwater recharge was calculated to amount to 1.4 million m3 in 2016. I developed a groundwater table height simulation model and analyzed catchment-scale spatial and temporal variability of groundwater levels, which allowed me to confirm that groundwater increases water supply during dry season to residents of the lower parts of the catchments. For villagers living in the upper parts of the catchments, my experiment suggests that rooftop water harvesting is the best water source during the dry season. Lastly, scenario analysis that links dry season water supplies with local poverty lock-in challenging strategies proves that animal husbandry is the best livelihood improving strategy for upper catchment residents, while crop irrigation is best suited for lower catchment residents’ livelihoods. After fulfilling household’s domestic water use need, rooftop water harvesting and groundwater respectively may enable farmers earning a profit estimated at US$69–7704 and US$1084–2504 during the dry season from a combination of animal fattening and crop irrigation. Overall, the methodology that I developed and the results that it generated are novel and significant because they identify a potential pathway to move out of sever poverty to a better livelihood within a sustainable environment. The research undertaken can be replicated for appropriate ESS management particular for hydrology-economic model development and policy, as well as for poverty alleviation in the Ethiopian-African rural highlands and to other rural communities worldwide that depend on ESS.Open Acces

Impact of Soil Conservation and Eucalyptus on Hydrology and Soil Loss in the Ethiopian Highlands

The Ethiopian highlands suffer from severe land degradation, including erosion. In response, the Ethiopian government has implemented soil and water conservation practices (SWCPs). At the same time, due to its economic value, the acreage of eucalyptus has expanded, with croplands and pastures converted to eucalyptus plantations. The impact of these changes on soil loss has not been investigated experimentally. The objective of this study, therefore, is to examine the impacts of these changes on stream discharge and sediment load in a sub-humid watershed. The study covers a nine-year period that included installation of SWCPs, a three-fold increase from 1.5 ha in 2010 to 5 ha in 2018 in eucalyptus, and the upgrading of an unpaved to the paved road. Precipitation, runoff, and sediment concentration were monitored by installing weirs at the outlets of the main and four nested watersheds. A total of 867 storm events were collected in the nine years. Runoff and sediment concentration decreased by more than half in nine years. In the main watershed W5, we estimated that evapotranspiration by eucalyptus during the dry phase (November to May) increased approximately from 30 mm a−1 in 2010 to 100 mm a−1 in 2018. In watershed W3 it increased from 2 mm a−1 to 400 mm a−1, requiring more rainfall before saturation excess runoff began in the rain phase. The reduction in runoff led to a decreased sediment load from 70 Mg ha−1 a−1 in 2010 to 2.8 Mg ha−1 a−1 in 2018, though the reduction in discharge may have negative impacts on ecology and downstream water resources. SWCPs became sediment-filled and minimally effective by 2018. This indicates that these techniques are either inappropriate for this sub-humid watershed or require improved design and maintenance

Predicting Shallow Groundwater Tables for Sloping Highland Aquifers

While hydrological science has made great strides forward during the last 50 years with the advance of computing power and availability of satellite images, much is unknown about the sustainable development of water for irrigation, domestic use, and livestock consumption for millions of households in the developing world. Specifically, quantification of shallow underground water resources for irrigation in highland regions remains challenging. The objective is to better understand the hydrology of highland watersheds with sloping hillside aquifers. Therefore, we present a subsurface flow model for hillside aquifers with recharge that varied from day to day. Recharge to the aquifer was estimated by the Thornthwaite Mather procedure. A characteristic time was identified for travel time of water flowing from the upper part of the hillside to the river or well. Using the method of characteristics, we found that the height of shallow groundwater level can be predicted by determining the total recharge over the characteristic time divided by drainable porosity. We apply the model to farmer‐dug wells in the Ethiopian highlands using observed rainfall, potential evaporation, and a fitted travel time. We find that the model performs well with maximum water table heights being determined by the soil surface and minimum heights by the presence or absence of volcanic dikes downhill. Our application shows that unless the water is ponded behind a natural or artificial barrier, hillslope aquifers are unable to provide a continuous source of water during the long, dry season. This clearly limits any irrigation development in the highlands from shallow sloping groundwater

Long-term trends of river flow, sediment yield and crop productivity of Andit tid watershed, central highland of Ethiopia

Andit tid watershed is part of Blue Nile basin located in the central highlands of Ethiopia. The lack of data and information at watershed level resulted in different conclusions from trend studies of river flow, sediment yield and crop productivity at a basin scale. There is an opportunity to improve water and land if it can be underpinned by a better scientific understanding of trends of flow, sediment yield and crop production at the basin level. This research is carried out using descriptive statistics, Mann-Kendall (MK), and Pettit’s test to determine the potential trends of river flow, sediment yield and crop productivity using Andit tid watershed case. The result showed that there was high variability of interannual river flow with CV>30%. The Pettitt test showed a significant abrupt change in monthly (March, July, August, September and October) and seasonal (summer and winter) river flow. The Pettitt test result of sediment yield and crop production showed no change. MK test showed a significant (P<0.05) decreasing trend in March, August, September and October River flow. The other MK values showed no significant trends for all parameters. Researchers should consider representative watershed-based information and data for the analysis and interpretation of large basins

Impact Assessment of Land use / Land Cover Change on Soil Erosion and Rural Livelihood in Andit Tid Watershed, North Shewa, Ethiopia

Land use, which is use of land by human for different purposes, is influenced by two broad sets of forces human needs (socio-economic) and environmental features and processes (biophysical). The study was carried out at Andit Tid watershed one of SCRP research unit founded in 1982, located on 390 43’E 9048’N.&nbsp; This research has aimed to assess the trend and main driving force of land use and land cover change (LULCC) within the catchment / watershed during the last two decades and its impact on soil erosion. Structural questioner was used to collect social data from 8% of the total household. Landsat 5 and Landsat 8 Enhanced Thematic Mapper (ETM) and supervised image classification used to identify land use/ land cover change of the study area for 1994 and 2014 years, respectively. TESTMAIN and SPSS version 16 Statistical software’s were used for Soil loss calculation and social data analysis, respectively. The result indicates that, there is expansion of cultivated land by 11.33% (44.55ha) while reduction in natural shrub lands by 7.3 % (35.73ha). The main driving forces of land use land cover change are high number of family member, small land holding size and minimum asset own per household, lower educational level of the household, the household mainly occupied on agriculture and there is lack of animal feed.&nbsp; This change forced farmers to collect cereal crops based on suitability area, sale livestock, use organic and inorganic fertilizer and use improved variety due to low crop productivity. The LULC change has an impact on decline soil fertility, cause serious soil erosion problem with in farmland/watershed. The result also indicated that soil loss reached 3655 ton per annum from the watershed. Therefore, proper handling and land use system need to be implemented, rainwater harvesting structures and soil and water conservation practice need to be encouraged in order reduce soil loss

Eco-hydrological impacts of Eucalyptus in the semi humid Ethiopian Highlands: the Lake Tana Plain

Abstract: Eucalyptus is the tree of choice for wood production by farmers in Ethiopia. Although there are many claims about its harmful effect on ecology and water availability, little actual research exists. The main objective of this study was, therefore, to study the extent of harm of Eucalyptus on the ecosystem. This study was conducted at the Koga Watershed near Lake Tana in Ethiopia. Twenty-five farmers were interviewed and a field experiment with three replications was carried out to quantify the effect of Eucalyptus on various soil physical and chemical properties and maize crop measurements and to compare bulk density, soil moisture contents, maize crop counts and shading effects in fields bordered by Eucalyptus and Croton macrostachyus. Our results show that Eucalyptus decreased both soil nutrients and maize yields within 20 m of the trees. Although moisture content was not affected during the monsoon, it decreased faster within 30 m of the Eucalyptus trees than elsewhere. Soils become water repellent, too. Local farmers ’ perception agreed with our experimental findings and indicated that Eucalyptus trees are exhausting the once productive land. They also reported that Eucalyptus dries up springs. Despite this, the growers insist on planting Eucalyptus because of its cas

Impact of Soil Conservation and Eucalyptus on Hydrology and Soil Loss in the Ethiopian Highlands

The Ethiopian highlands suffer from severe land degradation, including erosion. In response, the Ethiopian government has implemented soil and water conservation practices (SWCPs). At the same time, due to its economic value, the acreage of eucalyptus has expanded, with croplands and pastures converted to eucalyptus plantations. The impact of these changes on soil loss has not been investigated experimentally. The objective of this study, therefore, is to examine the impacts of these changes on stream discharge and sediment load in a sub-humid watershed. The study covers a nine-year period that included installation of SWCPs, a three-fold increase from 1.5 ha in 2010 to 5 ha in 2018 in eucalyptus, and the upgrading of an unpaved to the paved road. Precipitation, runoff, and sediment concentration were monitored by installing weirs at the outlets of the main and four nested watersheds. A total of 867 storm events were collected in the nine years. Runoff and sediment concentration decreased by more than half in nine years. In the main watershed W5, we estimated that evapotranspiration by eucalyptus during the dry phase (November to May) increased approximately from 30 mm a&minus;1 in 2010 to 100 mm a&minus;1 in 2018. In watershed W3 it increased from 2 mm a&minus;1 to 400 mm a&minus;1, requiring more rainfall before saturation excess runoff began in the rain phase. The reduction in runoff led to a decreased sediment load from 70 Mg ha&minus;1 a&minus;1 in 2010 to 2.8 Mg ha&minus;1 a&minus;1 in 2018, though the reduction in discharge may have negative impacts on ecology and downstream water resources. SWCPs became sediment-filled and minimally effective by 2018. This indicates that these techniques are either inappropriate for this sub-humid watershed or require improved design and maintenance