Deltas worldwide are at risk of elevation loss and drowning due to relative sea-level rise. Management strategies to restore or enhance sedimentation on delta plains, Sedimentation-Enhancing Strategies (hereafter SES), are now being pursued in many deltas but there has been limited cross-disciplinary and cross-delta review. Here we compare 21 existing and planned SES, synthesizing their physical characteristics, funding, governance arrangements, stakeholder engagement, process of implementation, environmental impact, land use change, and potential for upscaling. Strategies exist at various scales, from ~0.05 km² - 500 km². 79% of strategies are capable of outpacing high rates of sea-level rise. Cheaper strategies are limited to short term impacts and small spatial scales, while more expensive strategies can have longer lifetimes. Most strategies create wetlands and flood water storage. Some create opportunities for agriculture, aquaculture, housing, or recreational land use. Combinations of SES will likely be the most effective and sustainable method for maintaining elevation in river deltas.

Prediction of the shoreline response behind offshore breakwaters is essential for coastal protection projects. Due to the complexity of the processes behind the breakwaters (e.g., wave diffraction, currents, longshore transport), detailed modelling needs high computational efforts. Therefore, simplifying the process effect in a simpler coastline model could be efficient. In this study, the coastline evolution model ShorelineS is used. A new routine was implemented in the model to adjust the wave heights and angles behind the offshore breakwaters. Two approaches from the literature and a newly introduced one were tested in this study. The model free grid system was used to simply track the breaker line; such an advantage also helped to form tombolo, which is not common for these types of models. The tests showed promising results for single and multi breakwaters systems; however, the newly introduced approach still needs further testing and refinement for better performance and less computational cost.