Novel luminescence diagnosis of storm deposition across intertidal environments.

Salt marshes provide valuable nature-based, low-cost defences protecting against coastal flooding and erosion. Storm sedimentation can improve the resilience of salt marshes to accelerating rates of sea-level rise, which poses a threat to salt marsh survival worldwide. It is therefore important to be able to accurately detect the frequency of storm activity in longer-term sediment records to quantify how storms contribute to salt marsh resilience. Luminescence is able to infer how long mineral grains were exposed to sunlight prior to burial (e.g., the presence or absence of sediment processing). This study used sediment cores collected from the Ribble Estuary, North West England, to show that luminescence properties of sand-sized K-feldspar grains can diagnose the differential modes of deposition across intertidal settings (i.e., sandflat, mudflat and salt marsh) in longer-term sediment records by detecting the variability in sediment bleaching potential between settings (i.e., sediment exposure to sunlight), thus establishing a framework for the interpretation of luminescence properties of intertidal sediments. It then used modern sediment samples collected before and after a storm event to show how such properties can diagnose changes in sediment processing (i.e., bleaching potential) of mudflat sediments caused by storm activity, despite no changes in sediment composition being recorded by geochemical and particle size distribution analyses. This new luminescence approach can be applied to longer-term sediment records to reveal (and date) changes in the environment of deposition and/or depositional dynamics where there is no obvious stratigraphic evidence of such.

Dataset of results from numerical simulations of increased storm intensity in an estuarine salt marsh system.

This article contains data outlining the effects of increased storm intensity on estuarine salt marshes, previously evaluated in Pannozzo et al. (2021), using the Ribble Estuary, in North West England, as a case study. The hydrodynamic model Delft3D was used to simulate various surge height scenarios and evaluate the effects of increasing surge height on the sediment budget of the system. The data shows that an increase in storm intensity (i.e. surge height) promotes flood dominance and triggers a net import of sediment, positively contributing to the sediment budget of the marsh platform and the estuarine system. The timing of the storm surge relative to high or low tide, the duration of the surge and the presence of vegetation do not cause major changes in the sediment budget. This dataset could be used to evaluate how increased storm intensity might influence the sediment budget of estuaries in comparison to other types of coastal systems (e.g., bays) to illustrate how the response of salt marshes to increased storm intensity varies with a change in the hydrodynamics and sediment delivery dynamics of the system.

Experimental data used to validate the FE model of the structural performance of two flexible pipes laid in a single trench.

The objective of the article is to describe the methodology followed to validate the finite element model for the new method of setting pipes in a separate sewer system, using one trench to accommodate the storm pipe over the sanitary pipe "doi.org/10.1016/j.tust.2019.103019" (Abbas et al., 2019). A physical model was established in the Liverpool John Moores University (LJMU) lab to test the structural performance of two PVC pipes buried in one trench. The results of the physical model were used to validate an FE model using the same material properties and boundary conditions used in the physical model. The validation process allowed the FE model to be upgraded to a 3D FE full-scale model for testing the novel method used to place the separate sewer system.

Acoustic measurement and morphological features of organic sediment deposits in combined sewer networks.

The performance of sewer networks has important consequences from an environmental and social point of view. Poor functioning can result in flood risk and pollution at a large scale. Sediment deposits forming in sewer trunks might severely compromise the sewer line by affecting the flow field, reducing cross-sectional areas, and increasing roughness coefficients. In spite of numerous efforts, the morphological features of these depositional environments remain poorly understood. The interface between water and sediment remains inefficiently identified and the estimation of the stock of deposit is frequently inaccurate. In part, this is due to technical issues connected to difficulties in collecting accurate field measurements without disrupting existing morphologies. In this paper, results from an extensive field campaign are presented; during the campaign a new survey methodology based on acoustic techniques has been tested. Furthermore, a new algorithm for the detection of the soil-water interface, and therefore for the correct esteem of sediment stocks is proposed. Finally, results in regard to bed topography, and morphological features at two different field sites are presented and reveal that a large variability in bed forms is present along sewer networks.