|The use of a model to access factors affecting the oxygen balance in the water of the Dollard|
van Es, F.B.; Ruardij, P. (1982). The use of a model to access factors affecting the oxygen balance in the water of the Dollard. Neth. J. Sea Res. 15(3-4): 313-330
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
|Authors|| || Top |
A mathematical model was developed to calculate the contribution of several processes to the oxygen balance in the water of the Dollard. This model was based on a mixing and flushing model for the calculation of the dispersal of organic waste water discharged to the Dollard. Measured data were available of background and total oxygen consumption and primary production in the water, sediment respiration and decomposition rates of the organic waste. This enabled a mean reaeration coefficient to be estimated. The model satisfactorily described the distribution of oxygen concentrations in the Dollard, both in time and space. In summer, the oxygen balance was determined to the same amount by sediment respiration and oxygen consumption in the water, and in autumn largely by the waste discharges. The physical process of reaeration was the predominant oxygen providing process, though in summer primary production was important. The input of oxygen-rich water from the middle part of the estuary was of minor importance. During the highest waste water discharges the oxygen consumption in the mouth of the Dollard was 4 times the background level. Beyond that area the increase was negligible.