Sediment response dynamics

If any quantitative or qualitative target for sediment is to be set, this will need to take into account the highly dynamic nature of rivers. Furthermore, there is a need to differentiate by river type, to be inclusive of the whole river ecosystem and to look at the continuum of sediment quantity gradient and biological response. There is a requirement for scientists to improve our sediment system understanding, i.e. understanding... 

Soetaert, K., Herman, P.M.J. and Middelburg, J.J., 1996. Dynamic response of deep-sea sediments to seasonal variations A model.- Limnology and Oceanography, 41, 1651-1668. 

The relationships between particle flux, trace element flux and trace element concentration in sediment are more complicated in deep lakes. In a deep lake, there may be a significant proportion of dissolved element held in the water column. If the water column dissolved element inventory approaches the magnitude of the annual flux for that element, then a steady state model is invalid. Instead, the dynamic model outlined in Figure 7 must be used to allow for the time delay in the response of the sediment to changes in trace element supply rate. The disadvantage of this, compared with the steady state sitnation, is that an observed trace element concentration profile does not lead back to a nniqne trace element supply history. However, a trace element snpply history does lead to a definite trace element concentration profile, so it is possible to see if any particular supply history is compatible with the observed concentration data. A practical example of this from Lake Baikal is shown in Boyle et al. (1998), where the exceptional water depth makes this effect particularly strong. 

The dynamic model of Figure 7 can be used to illustrate the impact of water depth on the response of the sediment to changes in trace element supply. The effects on the sediment composition are illnstrated of five year episodes of doubled trace element supply rate (Fig. 8a), doubled particle deposition rate (Fig. 8b) and doubled (Fig. 8c), for different combinations of water depth and initial Ka-... 

J. L. DiLorenzo, The overtide and filtering response of small inlet/bay systems. Hydrodynamics and Sediment Dynamics of Tidal Inlets, eds. D. G. Aubrey and L. Weishar (Springer, 1988), pp. 24-53. 

Each level of the coastal-tract cascade is a self-contained system that shares sediments with other levels. This sediment sharing constrains morphologic responses of the system on given temporal and spatial scales. The internal dynamics of these responses involve morphologic coupling of the upper shoreface to the backbarrier... 

Kalkan E, Kunnath SK (2006) Effects of fling step and forward directivity on seismic response of buildings. Earthq Spectra 22(2) 367-390 King JL, Tucker BE (1984) Observed variations of earthquake motion across a sediment-filled valley. Bull Seismol Soc Am 74(1) 137-151 Kontoe S, Zdravkovic L, Potts DM, Menkiti CO (2011) On the relative merits of simple and advanced constitutive models in dynamic analysis of timnels. Geotechnique 61 815-829... 

The study of the dynamics of biogeochemical profiles governed by microorganisms at benthic interfaces (e.g. wood-water, sediment-water, microbial mat-water Figure 5.11) constitutes one of the keys for understanding the relationships between benthic diversity, the degradation of organic matter and responses to disturbances at different scales, either climate-driven or linked to direct impacts on the seabed. 

Estimates of net sedimentation rates made using the methods described above can range from negative (erosional) or essentially zero (dynamic equilibrium), to rates in the range of 1 to 4 cm/year, and upward to very high rates of deposition, usually in very localized areas or in response to imposed changes to the sedimentary... 

The textbook entitled Environmental Chemodynamics (Thibodeaux, 1996) was the first unified attempt to address multimedia chemical mass transfer in natural systems such as air, water, soil, sediments, etc. Arguably, mass transfer is the key chemo-dynamic process responsible for the presence of many anthropogenic chemicals worldwide as trace contaminants and these chemicals achieving pollutant levels at many locales. Mass transport coefficients (MTCs) are the kinetic parameters that quantify chemical movement rates within and between these natural media. Coefficient estimation methods based upon theoretically sound transport mechanisms... 

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