Factors Affecting Water Quality of (Large) Rivers-Past Experiences and Future Outlook

Man tends to generalize specific and real time experience into abstract reports and formulae. One such instrument for generalization is the formulation of mathematical models to reproduce observations and to extrapolate such observations into other frames of time and location. Effects of pollution and other factors upon water quality of (large) rivers are such examples, i.e., observations are so numerous and, if not reported in a more generalized form, the information becomes so heterogeneous if not contradictory, that it might be difficult to formulate a consistent concept of quality changing factors and of the processes which they initiate. Therefore, even very early quantitative attempts of water quality assessment and control have used the instrument of mathematical modeling to describe dominant factors that control or change river water quality and to quantify their effects.