Improving predictions of swash dynamics in XBeach: The role of groupiness and incident-band runup

In predicting storm impacts on sandy coasts, possibly with structures, accurate runup and overtopping simulation is an important aspect. Recent investigations (Stockdon et al., 2014; Palmsten and Splinter, 2016) show that despite accurate predictions of the morphodynamics of dissipative sandy beaches, the XBeach model (Roelvink et al., 2009) does not correctly simulate the individual contributions of set-up, and infragravity and incident-band swash to the wave run-up. In this paper we describe an improved numerical scheme and a different way of simulating the propagation of directionally-spread short wave groups in XBeach to better predict the groupiness of the short waves and the resulting infragravity waves. The new approach is tested against field measurements from the DELILAH campaign at Duck, NC, and against video-derived runup measurements at Praia de Faro, a relatively steep sandy beach. Compared to the empirical fit by Vousdoukas et al. (2012) the XBeach model performs much better for more extreme wave conditions, which are severely underestimated by existing empirical formulations.For relatively steep beaches incident-band swash cannot be neglected and a wave-resolving simulation mode is required. Therefore in this paper we also test the non-hydrostatic, wave-resolving model within XBeach for runup and overtopping against three datasets. Results for a high-quality flume test show non-hydrostatic XBeach predicts the run-up height with good accuracy (maximum deviation 15%). A case with a very shallow foreshore typical for the Belgian coast at Wenduine was compared against detailed measurements. Overall the model shows correct behavior for this case. Finally, the model is tested against a large number (551) of physical model tests of overtopping from the CLASH database. For relatively high overtopping discharges the non-hydrostatic XBeach performs quite well, with increasing accuracy for increasing overtopping rates. However, for relatively low overtopping rates of less than 10-20 l/m/s, the model systematically underestimates measured overtopping rates.Coastal Engineerin

Stakeholder’s Value Identification for Adaptive Port Planning: Case Study of Port of Ísafjordur in Iceland

Rivers, Ports, Waterways and Dredging Engineerin

Modelling of sedimentation processes inside Roseires Reservoir (Sudan)

Roseires Reservoir, located on the Blue Nile River in Sudan, is the first trap to the sediments coming from the vast upper river catchment in Ethiopia, which suffers from high erosion and desertification problems. The reservoir has already lost more than one-third of its storage capacity due to sedimentation in the last four decades. Appropriate management of the eroded soils in the upper basin could mitigate this problem. In order to do that, the areas providing the highest sediment volumes to the river have to be identified, since they should have priority with respect to the application of erosion control practices. This requires studying the sedimentation record inside Roseires Reservoir in order to assess when and how much sediment is deposited and to identify its source. This paper deals with the identification of deposition time and soil stratification inside the reservoir, based on historical bathymetric data, numerical modelling and newly acquired soil data. The remoteness of the study area and the extreme climate result in coring campaigns being expensive and difficult. Therefore, these activities need to be optimised and coring locations selected beforehand. This was done by combining bathymetric data and the results of a depth-averaged morphodynamic model recording the vertical stratification in sediment deposits. The model allowed for recognising the areas that are potentially subject to neither net erosion nor bar migration during the lifespan of the reservoir. Verification of these results was carried out by analysing sediment stratification from the data collected during the subsequent field campaign.Hydraulic EngineeringCivil Engineering and Geoscience

Modelling of sedimentation processes inside Roseires Reservoir (Sudan) (discussion)

Discussion paper. Roseires Reservoir, located on the Blue Nile River, in Sudan, is the first trap to the sediments coming from the upper catchment in Ethiopia, which suffers from high erosion and desertification problems. The reservoir lost already more than one third of its 5 storage capacity due to sedimentation in the last four decades. Appropriate management of the eroded area in the upper basin could mitigate this problem. In order to do that, the areas providing the highest sediment volumes to the river have to be identified, since they should have priority with respect to the application of erosion control practices. This requires studying the sedimentation record inside Roseires Reservoir, 10 with the aim of identifying when and how much sediment from a certain area is deposited. The identification of deposition time is derived from soil stratification inside the reservoir. This requires expensive coring campaigns that need to be optimized. The most promising sampling coring areas were therefore selected beforehand by combining bathymetric data and the results of a depth-averaged morphodynamic model able 15 to record vertical stratification in sediment deposits. The model allowed recognising the areas that are potentially neither subject to net erosion nor to bar migration during the life span of the reservoir. Verification of these results was carried out by analysing sediment stratification from the data collected in subsequent field campaign.Hydraulic EngineeringCivil Engineering and Geoscience

Framework for Dealing with Uncertainty in the Port Planning Process

Ports are complex engineering systems that have always been evolving to satisfy the new or changing demands of stakeholders. However, the ever-growing complexity in port sectors in a volatile environment creates a high degree of uncertainty in port planning projects. This study presents a structured framework to deal with uncertainties in the port planning process. Stakeholder analysis, different methods of addressing uncertain developments, and SWOT analysis were jointly used to develop the framework. Effective actions were planned in response to opportunities and vulnerabilities derived from uncertainties that manifest in a projected lifetime. Face-to-face interviews with key stakeholders and literature review were conducted to identify uncertainties and planning horizons. The framework was applied to the Ports of Isafjordur Network in Iceland. The results show that demand for aquaculture and cruise activities create the main uncertainties for the port network. Uncertainties mainly present opportunities in the short-term horizon, while in the middle-term horizon the port network is confronted with multiple vulnerabilities. The nonlinearity of dealing with uncertainty by application of the framework provides a robust and better plan toward its success in a dynamic world. The framework supports decision making under uncertainty by facilitating adaptive port planning.Accepted author manuscriptRivers, Ports, Waterways and Dredging Engineerin

Flexible and Adaptive Port Planning (PPT): Case Study of Port of Isafjordur

Accepted Author ManuscriptRivers, Ports, Waterways and Dredging Engineerin

A value-based definition of success in adaptive port planning: a case study of the Port of Isafjordur in Iceland

Multiple stakeholders with a wide range of objectives are engaged in a port system. Ports themselves are faced with many uncertainties in this volatile world. To meet stakeholder objectives and deal with uncertainties, adaptive port planning is increasingly being acknowledged. This method offers robust planning, and thereby, a sustainable and flexible port may be developed. The planning process starts with defining success in terms of the specific objectives of stakeholders during the projected lifetime of the port. In the present work, an integrated framework to reach a consensus on the definition of success, involving stakeholders with different influences, stakes and objectives, is presented. The framework synthesises the problem structuring method with stakeholder analysis and combines these with fuzzy logic to support decision-makers in formulating a definition of success in the planning process. Our framework is applied to the Port of Isafjordur, the third busiest port of call for cruise ships in Iceland. Values of stakeholders about port planning were structured around the value-focussed thinking method to identify stakeholder objectives. The highest level of agreement on the objectives, which is viewed here as success in port planning, was revealed by the fuzzy multi-attribute group decision-making method. Success was defined, prioritising an increase in competitiveness among other planning objectives, such as effective and efficient use of land, increasing safety and security, increasing hinterland connectivity, increasing financial performance, better environmental implications, flexibility creation and increasing positive economic and social impacts.Accepted author manuscriptRivers, Ports, Waterways and Dredging Engineerin

Stakeholder salience and prioritization for port master planning, a case study of the multi-purpose Port of Isafjordur in Iceland

The dynamic and ever-increasing complex nature of a port system involves a variety of stakeholders with a broad spectrum of involvement and objectives. In the port master planning, to fulfill the objectives of the various stakeholders and manage conflicts and controversies, a stakeholder analysis is carried out. However, effective and timely engagement of the key stakeholders in the planning process is not an easy task. This paper presents a framework of stakeholder analysis for the case study of the Multi-Purpose Port of Isafjordur in Iceland to underpin the master planning process. The framework deals with a systematic procedure of identification, grouping and then static mapping of stakeholders by means of the power-interest matrix. Further, the fuzzy logic 3-dimensional decision surface was adopted for dynamic salience mapping of the stakeholders. A survey and face-to-face interviews were conducted as tools to collect input for the stakeholder analysis based on the elements of the port master planning. The elements include competitiveness, land use, environmental implication, safety and security, hinterland connection, economic and social impact, financial performance, and flexibility. This paper reveals that dynamic mapping provides a more accurate stakeholder analysis in the field of port master planning than do other methods. The result of the decision surface shows different saliences of key stakeholders, including legislation and public policy, and internal and external stakeholders in the master planning. Thus, in order to have effective and timely stakeholder inclusion throughout the port planning process, a different strategy of engagement with them should be applied. Rivers, Ports, Waterways and Dredging Engineerin