The Blue Nile is characterised by growing tensions between Ethiopia, Sudan and Egypt related to increasing demands for water and upcoming unilateral developments. Growing efforts towards basin wide cooperation from the international and scientific community have led to the development of a common decision support tool, the Nile Basin Decision Support System (NBDSS), but applications are still limited. This thesis assumes that a discrepancy between values included in the design of the NBDSS and values that actually play a role in decision making might contribute to the lack of implementation. This assumption involves two important research gaps, namely the absence of a clear overview of values of decision makers in the Blue Nile countries and the capabilities of the NBDSS in considering all values in decision making. This thesis aims to fill these research gaps and finally test the assumption by evaluating the NBDSS from a value perspective. The evaluation uses four elements, namely design requirements to allow value considerations, design values of the NBDSS, actor values and associated potential conflicts and synergies. This thesis produced two main results that are valuable to the academic community, namely a list of values associated with water resources for each Blue Nile country and an evaluation of the NBDSS from a value perspective.
Literature review resulted in five design requirements: transparency, participatory development, flexibility, useful information and reasonable value judgements. Document analysis and model assessment yielded nine design values that should constitute the core functionalities of the system, namely economy, environment, equity, inclusiveness, international cooperation, society, sustainability, trust and usability. However, none of the analysed documents on the NBDSS talks about value considerations explicitly...
... Read more

The United States Army Corps of Engineers (USACE) is scheduled to present their solution for a storm surge barrier on Galveston Island in 2021 to congress for approval. A solution for an engineered dune system on the Galveston Island West End has been proposed, but storm surge models have shown that protection from this engineered dune only goes so far, moreover the search for a proper alternative that fulfills technical requirements and social political influences have proven to be challenging. This study aimsto assess different dune alternatives, proposed in different reports, with a range of multi disciplinary criteria. The assessment of dune alternatives will also result in guidelines that should be considered for design, maintenance and governance aspects for an engineered dune barrier on Galveston Island, TX. Using a multi disciplinary approach for the evaluation of the different dune alternatives, the following research question was formulated: To what extent do the various dune alternatives fit the requirements for a land barrier at the West End of Galveston Island, looking at both technical and sociopolitical aspects? In this context, technical requirements are defined as the storm surge-and rainfall coping capacities of the dune, i.e. against what kind of storm is the dune resistant. Social political influences are a combination of the perception by local residents that are directly influenced by the construction of a dune system, governmental forms of collaboration, and in provide an analysis of the maintainability of the dune alternatives using the storm surge capacities. The different dune alternatives that have been assessed consist of the dune system proposed by the USACE and GLO (2018), the big dune system proposed by Galvez (2019) and the hybrid dune system as proposed by Muller (2017) and will hereafter be called alternative 1, 2 and 3 respectively. In this report a fourth alternative was introduced which is based on the hybrid dune system by Muller (2017) and consists of a clay core instead of a concrete core. Alternative 4 was chosen in order to simulate the difference between a concrete core and a clay core. Based on XBeach calculations, the storm surge coping capability of each dune was determined by projecting 10 year-, 50 year- and 100 year storms onto the dune alternatives. ArcGIS maps from the Galveston Island allowed for projection of flow patterns on the island in order to determine the rainfall coping capacity. An evaluation of sociopolitical aspects was based on a review of the literature on dune systems, forms of collaboration between governmental and private entities, and interviews with various respondents consisting of private individuals and companies, as well as governmental agencies involved in the process. Analysis of the various dune alternatives, based on multi disciplinary criteria, demonstrated that alternative 1 is completely flattened in 50 year storm events, whereas alternatives 2, 3 and 4 show a good storm surge capacity. All alternatives aggravate the current rainfall capacity at Galveston Island West End, because each dune system poses an obstruction that is not there currently. Alternatives 2 through 4 show a good enough storm resilience, requiring post-storm recovery maintenance while still providing a reduced but fair storm surge capacity. The sociopolitical results indicate that Galveston Island West End residents wishes are only safeguarded for alternative 1. On this basis, the main recommendations are to perform tests upon the dune system alternatives regarding storm events occurring in succession, which is not unusual in the Gulf of Mexico. A combination of alongshore erosion rates from the Galveston Island and the effect of dune vegetation should be determined for the dune alternatives, since these aspects were not considered in this research. Further research is needed to identify the combined effects of rainfall and storm surge in order to get insights into the performances of a certain alternatives. Furthermore, the exact role including the desired storm surge capability should be well defined in order to determine which stakeholder wishes and influences are to be fully considered for the dune system design. ... Read more