Summertime conditions of a muddy estuarine environment: the EsCoSed project contribution

Abstract

As part of the Estuarine Cohesive Sediments (EsCoSed) project, a field experiment was performed in a highly engineered environment, acting as a natural laboratory, to study the physico-chemical properties of estuarine sediments and the associated hydro-morphodynamics during different seasons. The present contribution focuses on the results obtained from the summertime monitoring of the most downstream part of the Misa River (Senigallia, Italy). The measured hydrodynamics suggested a strong interaction between river current, wave forcing and tidal motion; flow velocities, affected by wind waves traveling upstream, changed significantly along the water column in both direction and magnitude. Surficial salinities in the estuary were low in the upper reaches of the estuary and exceeded 10 psu before the river mouth. Montmorillonite dominated the clay mineral assemblage, suggesting that large, low density flocs with high settling velocities (>1 mm s(-1)) may dominate the suspended aggregate materials.

Medium-term dynamics of a middle Adriatic barred beach

“…1). As observed during recent field experiments, the Misa river estuary is dynamic throughout the year and especially during sea storms driven by NNE winds, which mobilize a large amount of sediment and generate significant erosion/deposition patterns nearby the rigid structures (Brocchini et al, 2015(Brocchini et al, , 2017. The investigated site is characterized by a swash-zone slope in the range 1 : 30-1 : 40, an array of submerged bars in a water depth h = 0-3 m and a mild slope of about 1 : 200 for h > 3 m (Fig.…”

“…3a-d do not refer to the prevalent conditions occurring, respectively, in summer and winter, but mainly refer to the most severe winter storms (Fig. 3e), the summertime being characterized by milder wave conditions, due to less strong winds and slowly changing wind directions during storms (see also Brocchini et al, 2015). Further, the fairly well distributed frequency, with respect to the more peaked energy flux, indicates that the annual variability of storms is not bound to the seasonal variability of wave climate.…”

Comparison between the wintertime and summertime dynamics of the Misa River estuary

“…The first of two experimental campaigns was carried out during the summertime in September 2013 (Brocchini et al, 2015). The summertime experiment was smaller in scope and duration than the primary wintertime experiment executed from 20-31 January 2014.…”

“…Sampling was conducted between two winter storms that occurred on 25 and 28 January 2014, respectively. The details of the summertime data collection were previously described (Brocchini et al, 2015).…”

“…Reference source not found. ), comparisons were made with the data previously collected during the summertime experiment (Brocchini et al, 2015), showing a fairly different behavior of the final reach and estuary in summer and winter, with low-flow conditions promoting sediment/flocs deposition and the high-flow conditions promoting: i) riverbed erosion, ii) large sediment suspension and development of the river plume, iii) complex morphological patterns at the mouth, due to convergence of sea and river forcing. Some conclusions are presented in Section 6.…”