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

Abstract

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.